Commit Graph

53589 Commits

Author SHA1 Message Date
Linus Torvalds
a27611f899 Perf events fixes:
- Fix race between perf_event_exit_task() and perf_pending_task()
    (Luo Gengkun)
 
  - Fix perf header output management regressions (Ian Rogers)
 
  - Require kernel access for text poke events (Zhengchuan Liang)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-urgent-2026-10-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf events fixes from Ingo Molnar:

 - Fix race between perf_event_exit_task() and perf_pending_task()
   (Luo Gengkun)

 - Fix perf header output management regressions (Ian Rogers)

 - Require kernel access for text poke events (Zhengchuan Liang)

* tag 'perf-urgent-2026-10-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Require kernel access for text poke events
  perf: Replace perf_event_header__init_id with full header init
  perf: Fix race between perf_event_exit_task() and perf_pending_task()
2026-10-04 08:35:29 -07:00
Linus Torvalds
1c915d6007 Locking fixes:
- Don't run refcount kunit self-test when !CONFIG_KUNIT_ALL_TESTS
    (Kuan-Wei Chiu)
 
  - Fix futex private hash use-after-free on resize (Chris Mason)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'locking-urgent-2026-10-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Ingo Molnar:

 - Don't run refcount kunit self-test when !CONFIG_KUNIT_ALL_TESTS
   (Kuan-Wei Chiu)

 - Fix futex private hash use-after-free on resize (Chris Mason)

* tag 'locking-urgent-2026-10-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Fix private hash use-after-free on resize
  irq: Make refcount_interrupt kunit test selectable
2026-10-04 08:29:27 -07:00
Linus Torvalds
e767a4ea70 Probes fixes for v7.3-rc5:
- fprobe: Use guard(rcu_sched_notrace) and check rcu_is_watching():
    Exit handlers early if !rcu_is_watching() to prevent potential
    use-after-free during unregistration in idle/quiescent states. Switch
    to guard(rcu_sched_notrace) to avoid fast-path lockdep overhead and
    recursion while ensuring safe grace period synchronization.
 
 - kprobes: Skip disarmed probes when checking optkprobe overlap:
    Continue past disarmed or unprepared probes in get_optimized_kprobe()
    to find active optimized probes. This avoids overwriting active jump
    displacements which can lead to panic.
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Merge tag 'probes-fixes-v7.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes fixes from Masami Hiramatsu:

 - fprobe: Use guard(rcu_sched_notrace) and check rcu_is_watching()

   Exit handlers early if !rcu_is_watching() to prevent potential
   use-after-free during unregistration in idle/quiescent states. Switch
   to guard(rcu_sched_notrace) to avoid fast-path lockdep overhead and
   recursion while ensuring safe grace period synchronization.

 - kprobes: Skip disarmed probes when checking optkprobe overlap

   Continue past disarmed or unprepared probes in get_optimized_kprobe()
   to find active optimized probes. This avoids overwriting active jump
   displacements which can lead to panic.

* tag 'probes-fixes-v7.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  kprobes: Skip disarmed probes when checking optkprobe overlap
  fprobe: Use guard(rcu_sched_notrace) and check rcu_is_watching()
2026-10-02 17:34:18 -07:00
Linus Torvalds
8f150ccedf bpf-fixes
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Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Pull bpf fixes from Alexei Starovoitov:

 - Fix overflow of backward jump offset in constant blinding
   (Alexei Starovoitov)

 - Fix packet range of packet pointers sharing an id when var_off
   tightens umax of one pointer and not the other (Alexei Starovoitov)

 - Fix objects stuck in free_by_rcu_ttrace list of bpf memalloc
   (Alexei Starovoitov)

 - Fix use-after-free of progs detached from busy trampolines: wait for
   an RCU tasks grace period before freeing trampoline progs, and patch
   detached progs out of trampoline images that are still in use
   (Florent Revest)

 - Hold map BTF for the memory allocator destructor record to fix UAF in
   deferred bpf_mem_alloc destruction (Kumar Kartikeya Dwivedi)

 - Fix missing migration protection in resizable hashtab
   lookup_and_delete batch operation (Ömer Mete Kaya)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Fix missing migration protection in __rhtab_map_lookup_and_delete_batch()
  selftests/bpf: Add a test for objects stuck in free_by_rcu_ttrace
  bpf: Fix objects stuck in free_by_rcu_ttrace
  bpf: Factor out __do_call_rcu_ttrace()
  selftests/bpf: Test packet range of pointers sharing an id
  bpf: Fix packet range of pointers sharing an id
  selftests/bpf: Detach a trampoline prog while a task sleeps before it
  bpf: Skip detached progs in trampoline images that are still in use
  bpf: Wait for an RCU tasks grace period before freeing trampoline progs
  bpf: Hold map BTF for the memory allocator destructor record
  bpf: Fix overflow of jump offset in constant blinding
2026-10-02 12:59:32 -07:00
Ömer Mete Kaya
de020dc804
bpf: Fix missing migration protection in __rhtab_map_lookup_and_delete_batch()
bpf_mem_cache_free_rcu() uses this_cpu_ptr() which requires migration
to be disabled. All callers of rhtab_delete_elem() disable migration
except __rhtab_map_lookup_and_delete_batch(), which calls it under
rcu_read_lock() only.

On CONFIG_PREEMPT_RCU, rcu_read_lock() does not disable preemption or
migration, so the task can migrate between CPUs during the delete loop,
causing this_cpu_ptr() to trigger:

  BUG: using smp_processor_id() in preemptible [00000000] code

Fix by wrapping the delete loop in migrate_disable()/migrate_enable()
in __rhtab_map_lookup_and_delete_batch(), matching the migration
protection that the other callers already provide.

Fixes: 818e008482 ("bpf: Implement iteration ops for resizable hashtab")
Reported-by: syzbot+fd7e415d891073b83e1f@syzkaller.appspotmail.com
Signed-off-by: Ömer Mete Kaya <omermetekaya0@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://patch.msgid.link/20260929081609.557899-1-omermetekaya0@gmail.com
Closes: https://syzkaller.appspot.com/bug?extid=fd7e415d891073b83e1f
2026-10-02 11:34:15 +00:00
Chris Mason
f35e3b5784 futex: Fix private hash use-after-free on resize
poll_state_synchronize_rcu(mm->futex.phash.batches) is used by
futex_ref_drop() to check that a grace period has passed since the
current hash was published. This relies on batches referencing a grace
period which started after the hash pointer was assigned.

__futex_pivot_hash() sets mmph->batches before it replaces mmph->hash:

    scoped_guard(rcu) {
            mmph->batches = get_state_synchronize_rcu();
            rcu_assign_pointer(mmph->hash, new);
    }

The scoped_guard(rcu) doesn't stop new grace periods from starting, and
if one starts between those two assignments, futex_ref_drop() can move
forward while a reader still holds a pointer to the old hash.

Fix things by setting mmph->batches after assigning mmph->hash.  The
scoped_guard(rcu) isn't needed, so let's drop that as well.

Fixes: 56180dd20c ("futex: Use RCU-based per-CPU reference counting instead of rcuref_t")
Assisted-by: kres
Signed-off-by: Chris Mason <mason@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://patch.msgid.link/20261001135022.2220288-1-mason@kernel.org
2026-10-02 11:47:13 +02:00
Kuan-Wei Chiu
26f6b6357b irq: Make refcount_interrupt kunit test selectable
Currently, refcount_interrupt_test is built unconditionally when
CONFIG_KUNIT is enabled, causing it to run unexpectedly during boot.

Fix this by introducing CONFIG_REFCOUNT_INTERRUPT_KUNIT_TEST so the
test can be configured independently, following standard kunit
practices.

Fixes: 07a88e2bcd ("irq: Add KUnit test for refcounted interrupt enable/disable")
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Radu Rendec <radu@rendec.net>
Reviewed-by: Boqun Feng <boqun@kernel.org>
Link: https://patch.msgid.link/20261001082519.16195-2-boqun@kernel.org
2026-10-02 11:40:12 +02:00
Leon Hwang
7a39c732a2 kprobes: Skip disarmed probes when checking optkprobe overlap
On x86, an optkprobe at A replaces five bytes with a jump. If a disabled
probe B is at A+2, get_optimized_kprobe() stops at B when arming a new
probe C at A+4. It leaves A optimized:

              A    A+1  A+2  A+3  A+4
  A's jump  | e9 | d0 | d1 | d2 | d3 |
  after C   | e9 | d0 | d1 | d2 | cc |

The INT3 for C overwrites the last byte of A's jump displacement, so
execution can jump to the wrong address. B can have prepared optinsns
while disarmed, but has no jump to unoptimize.

Continue past disarmed and unprepared probes to find the active optimized
probe before arming a probe in its jump.

Link: https://lore.kernel.org/all/20260930053618.104498-1-leon.hwang@linux.dev/

Fixes: afd66255b9 ("kprobes: Introduce kprobes jump optimization")
Cc: stable@vger.kernel.org
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-10-02 15:51:57 +09:00
Alexei Starovoitov
fbd97dd1d3
bpf: Fix objects stuck in free_by_rcu_ttrace
do_call_rcu_ttrace() returns early when call_rcu_ttrace_in_progress is set
and leaves the objects in free_by_rcu_ttrace. __free_rcu() frees
waiting_for_gp_ttrace only and clears the flag. Hence the objects that
free_bulk() or __free_by_rcu() added while RCU tasks trace GP was in flight
stay in free_by_rcu_ttrace until free_bulk() or alloc_bulk() is called for
the same bpf_mem_cache again, which may never happen. The number of such
objects is not bounded.

Turn call_rcu_ttrace_in_progress into three states:
0 - idle
1 - __free_rcu() is queued
2 - __free_rcu() is queued and free_by_rcu_ttrace got more objects since

do_call_rcu_ttrace() sets 2. __free_rcu() does cmpxchg(1 -> 0) and starts
the next GP when it fails. It cannot clear the flag first and check
free_by_rcu_ttrace later, since bpf_mem_alloc_destroy() frees bpf_mem_cache
without waiting for RCU callbacks when the flag is zero.

Now __free_rcu() queues itself, so the one that didn't see 'draining' may
do call_rcu_tasks_trace() after rcu_barrier_tasks_trace() in
free_mem_alloc(). Queue it under rcu_read_lock() and do synchronize_rcu()
before the barriers. Calling rcu_barrier_tasks_trace() twice works too, but
creating and destroying hash maps in a loop on many cpus slows down to one
free_mem_alloc() per GP and kworkers pile up.

Fixes: 8d5a8011b3 ("bpf: Batch call_rcu callbacks instead of SLAB_TYPESAFE_BY_RCU.")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260930095920.601738-3-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-10-01 18:40:04 +02:00
Alexei Starovoitov
47f4f695ce
bpf: Factor out __do_call_rcu_ttrace()
Move the part of do_call_rcu_ttrace() that runs after
call_rcu_ttrace_in_progress is set into __do_call_rcu_ttrace().
The next patch will call it from __free_rcu().
No functional change.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260930095920.601738-2-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-10-01 18:40:04 +02:00
Alexei Starovoitov
b88822d258
bpf: Fix packet range of pointers sharing an id
Since commit 022ac07508 ("bpf: use reg->var_off instead of reg->off
for pointers"), find_good_pkt_pointers() sets the range of all packet
pointers sharing an id from the umax of the compared pointer, and
check_packet_access() requires umax + off + size <= range.  That assumes
the umax of two such pointers differ by exactly their constant distance.
reg_bounds_sync() breaks it when var_off tightens one umax and not the
other:

	r4 &= 0x38
	if r4 > 50 goto exit     ; umax 50, var_off (0x0; 0x38)
	r5 = pkt + r4            ; umax 50
	r6 = r5
	r6 += 8                  ; umax 56, not 58

Comparing r6 with pkt_end sets the range to 56, and the valid 8-byte
load at r5 is rejected (50 + 8 > 56).  Comparing r5 sets it to 50, and
the out-of-bounds 1-byte load at r6 - 7, i.e. r5 + 1, is accepted
(56 - 7 + 1 <= 50).

Don't call reg_bounds_sync() on a packet pointer that keeps its id (a
constant was added or subtracted) or its range (an unknown non-negative
value was subtracted), so that var_off cannot tighten its umax.  Only
update the 32-bit bounds from var_off: reg_bounds_sanity_check() wants
them constant when the lower half of var_off is, e.g. for pkt + 8.

This relies on nothing else changing the 64-bit bounds of a packet
pointer, which holds today.

var_off of such a pointer is no longer narrowed by its bounds.  Adjust
three verifier_align expectations; the low bits, which the alignment
checks use, don't change.  veristat on the selftests shows no verdict
changes and +0.8% insns in test_cls_redirect_subprogs.

Fixes: 022ac07508 ("bpf: use reg->var_off instead of reg->off for pointers")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20261001145255.855630-1-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-10-01 18:39:27 +02:00
Linus Torvalds
703033e235 Summary
* Fix sysctl jiffies conversions errors introduced in 2dc164a48e ("sysctl:
   Create converter functions with two new macros")
 
   - Ensure that mult_hz does *not* wrap
   - Ensure we pass just the magnitude for the negative branch in
     proc_int_k2u_conv_kop
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Merge tag 'sysctl-7.03-fixes-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl

Pull sysctl fixes from Joel Granados:
 "Fix sysctl jiffies conversions errors introduced in 2dc164a48e
  ("sysctl: Create converter functions with two new macros")

   - Ensure that mult_hz does *not* wrap

   - Ensure we pass just the magnitude for the negative branch in
     proc_int_k2u_conv_kop"

* tag 'sysctl-7.03-fixes-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  time/jiffies: Saturate in mult_hz() instead of wrapping
  sysctl: Negate before converting in the int read path
2026-10-01 06:31:40 -07:00
Zhengchuan Liang
357e8a77a5 perf: Require kernel access for text poke events
Perf events with exclude_kernel=1 can be opened without kernel perf
access. However, exclude_kernel does not suppress text-poke sideband
records. Every PERF_RECORD_TEXT_POKE is marked PERF_RECORD_MISC_KERNEL
and contains a raw kernel instruction address.

An unprivileged task can therefore open and mmap a task-local software
event with text_poke=1. Both opening a count-only tracepoint event and
configuring UDP GRO for ESP-in-UDP cause updates to inline static calls;
the observer receives the relocated addresses of the modified instructions.
For a known kernel image, any such address reveals the runtime kernel
text base despite KASLR.

Call perf_allow_kernel() whenever attr.text_poke is set, regardless of
exclude_kernel. Events that neither monitor kernel execution nor request
text-poke records retain their existing permissions.

Fixes: e17d43b93e ("perf: Add perf text poke event")
Assisted-by: LLM
Signed-off-by: Zhengchuan Liang <zcliangcn@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/99131354c41e23188f778b92f90363775b482395.1790573390.git.zcliangcn@gmail.com
2026-10-01 14:02:06 +02:00
Ian Rogers
b9d1fdc6f4 perf: Replace perf_event_header__init_id with full header init
perf_iterate_sb() invokes its callback for each matching perf_event on
the CPU and task context, passing a shared caller-allocated event
structure.

perf_event_header__init_id() mutated header->size in place by adding
event->id_header_size, requiring sideband output callbacks to save and
restore header fields across iterations. Three sideband callbacks failed
to save and restore header.size around perf_event_header__init_id():
 - perf_event_ksymbol_output()
 - perf_event_bpf_output()
 - perf_event_text_poke_output()

When multiple events with attr.ksymbol, attr.bpf_event, or
attr.text_poke and sample_id_all are active on the same CPU, each
subsequent event receives a record whose header.size is inflated by all
preceding events' id_header_size values while only a single id_sample is
written, leaving uninitialized ring-buffer bytes at the end of the
record and causing userspace perf to fail with -EFAULT ("Bad address")
when parsing the sample_id trailer.

Similarly, perf_event_mmap_output() set PERF_RECORD_MISC_MMAP_BUILD_ID
in mmap_event->event_id.header.misc when event->attr.build_id was
enabled, but only saved and restored header.size and header.type. If an
event with attr.build_id was followed by an event with attr.mmap2 and
!attr.build_id, the second event received PERF_RECORD_MISC_MMAP_BUILD_ID
in header.misc while its payload contained maj/min/ino/ino_generation
instead of a build ID.

Rather than splitting header initialization between callers and output
callbacks and saving/restoring mutated header fields, replace
perf_event_header__init_id() with perf_event_header__init(), which
initializes header->type, header->misc, and header->size alongside the
sample_id fields on each invocation.

Fixes: 76193a9452 ("perf, bpf: Introduce PERF_RECORD_KSYMBOL")
Fixes: 6ee52e2a3f ("perf, bpf: Introduce PERF_RECORD_BPF_EVENT")
Fixes: e17d43b93e ("perf: Add perf text poke event")
Fixes: 88a16a1309 ("perf: Add build id data in mmap2 event")
Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260929222332.973435-1-irogers@google.com
Cc: stable@vger.kernel.org
2026-10-01 14:02:06 +02:00
Luo Gengkun
ffb684f2aa perf: Fix race between perf_event_exit_task() and perf_pending_task()
A race condition exists between perf_event_exit_task() and
perf_pending_task() during begin_new_exec().

During begin_new_exec(), perf_event_exit_task() may be called, and the
PF_EXITING flag is not set on task. So perf_sigtrap() continues to execute
and triggers WARN_ON_ONCE(event->ctx->task != current).

Since both task exit and exec paths can call perf_event_exit_task() which
sets ctx->task to TASK_TOMBSTONE, fix this by explicitly checking if
event->ctx->task equals TASK_TOMBSTONE and dropping the redundant
PF_EXITING check.

Fixes: 97ba62b278 ("perf: Add support for SIGTRAP on perf events")
Signed-off-by: Luo Gengkun <luogengkun2@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260920075026.990582-1-luogengkun2@huawei.com
2026-10-01 14:02:05 +02:00
Linus Torvalds
5cd9813d84 audit/stable-7.3 PR 20260930
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Merge tag 'audit-pr-20260930' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

Pull audit fix from Paul Moore:
 "A single audit fix for a potential UAF error in some audit filter
  configurations"

* tag 'audit-pr-20260930' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: fix exe mark UAF in kill_rules()
2026-09-30 19:08:10 -07:00
Masami Hiramatsu (Google)
e0a6249190 fprobe: Use guard(rcu_sched_notrace) and check rcu_is_watching()
unregister_fprobe() and unregister_fprobe_async() (used by BPF
kprobe-multi) rely on standard RCU grace periods (synchronize_rcu()
and call_rcu()) to wait until in-flight fprobe handlers complete before
freeing the fprobe.

However, if an fprobe handler executes while RCU is not watching (such
as in the idle loop or nohz_full extended quiescent states), standard
RCU does not track preemption-disabled sections. Consequently,
synchronize_rcu() does not wait for those executions, which can lead
to a use-after-free if the fprobe is freed immediately after
unregistration. Ensure handlers exit early when !rcu_is_watching().

Furthermore, fprobe_fgraph_entry() and fprobe_ftrace_entry() previously
used guard(rcu)() and rcu_read_lock(), which invoke lockdep on every
hit under CONFIG_PROVE_LOCKING. This adds overhead and can cause lockdep
recursion if probed functions interact with lockdep.

Since rhltable_lookup() and rhl_for_each_entry_rcu() use
rcu_dereference_all_check() (which checks rcu_read_lock_any_held()),
holding preemption disabled via rcu_read_lock_sched_notrace() is fully
valid and sufficient so long as rcu_is_watching() is true.

Define and use guard(rcu_sched_notrace)() across fprobe_ftrace_entry(),
fprobe_fgraph_entry(), and fprobe_return(). This eliminates fast-path
rcu_read_lock() and lockdep overhead while guaranteeing safe grace
period synchronization.

Link: https://lore.kernel.org/all/179064115227.394389.16910234241400391996.stgit@devnote2/

Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/bug/linux-e46bcd68-4a56-4f19-a255-e3772980e5e3
Fixes: 657b594b20 ("fprobe: Fix unregister_fprobe() to wait for RCU grace period")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
2026-09-30 08:41:31 +09:00
Zhan Xusheng
fdd6553e1e time/jiffies: Saturate in mult_hz() instead of wrapping
Return ULONG_MAX for values that don't fit an unsigned long.
proc_int_u2k_conv_uop() now correctly rejects a result above INT_MAX.

This is the erroneous behaviour that is being fixed. The input has to
exceed ULONG_MAX / HZ for the product to wrap, so the value below is
specific to CONFIG_HZ=1000:

  # echo 18446744073709552 > /proc/sys/net/ipv4/tcp_keepalive_time
  # cat /proc/sys/net/ipv4/tcp_keepalive_time
  0

That value is now rejected with an error.

The original bound ("*u_ptr > INT_MAX / HZ") was removed in commit
2dc164a48e ("sysctl: Create converter functions with two new macros").

Fixes: 2dc164a48e ("sysctl: Create converter functions with two new macros")
Cc: stable@vger.kernel.org
Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
2026-09-29 10:00:40 +02:00
Zhan Xusheng
e955f14fa8 sysctl: Negate before converting in the int read path
proc_int_k2u_conv_kop() reports the sign through *negp and the magnitude
through *u_ptr, but for a negative value it hands the sign-extended int to
the converter and negates the result:

	*u_ptr = k_ptr_op ? -k_ptr_op((ulong)val) : -(ulong)val;

With div_hz() and CONFIG_HZ=1000 a stored -1000 becomes
(ulong)-1000 / 1000 == 18446744073709550, and negating that wraps:

	# echo -1 > /proc/sys/net/ipv4/tcp_fin_timeout
	# cat /proc/sys/net/ipv4/tcp_fin_timeout
	-18428297329635842066

The magnitude is HZ dependent but the wrap is not: the negation happens
after the division at every CONFIG_HZ.

Take the magnitude first and convert that, which is what the open-coded
version did before commit 2dc164a48e ("sysctl: Create converter
functions with two new macros") folded it into a macro.  The
k_ptr_op == NULL branch was already correct.

All three int converters that pass a k_ptr_op are affected:
proc_dointvec_jiffies(), proc_dointvec_userhz_jiffies() and
proc_dointvec_ms_jiffies().

Fixes: 2dc164a48e ("sysctl: Create converter functions with two new macros")
Cc: stable@vger.kernel.org
Reviewed-by: Bradley Morgan <brads@mainlining.org>
Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
2026-09-29 09:25:14 +02:00
Florent Revest (Anthropic)
17637e1a58
bpf: Skip detached progs in trampoline images that are still in use
bpf_tramp_image_put() makes sure a trampoline image is not freed while
a task may still be running in it, but nothing similar is done for the
progs called by that image. Detach drops the last prog reference right
away and the prog is freed after grace periods, on the basis that a
task still in the traced function skips the fexit progs once the nop at
ip_after_call is patched to a jump.

That leaves out a task sleeping in a sleepable prog that runs before
the detached one, which no grace period waits for:

  CPU 0                               CPU 1
  in image I, sleeping in prog S
                                      detach P from I's trampoline
                                       -> new image, bpf_tramp_image_put(I)
                                      bpf_prog_put(P), last ref
                                      grace periods, P freed
  back from S
  __bpf_prog_enter(P)
  call P->bpf_func

If S and P are fexit progs the task is already past the patched jump,
and fentry only images don't have one. On x86 this is an int3 in
poisoned bpf_prog_pack memory:

  Oops: int3: 0000 [#1] SMP NOPTI
  CPU: 18 UID: 0 PID: 94573 Comm: x169 Not tainted 6.18.44 #1 PREEMPT(lazy)
  RIP: 0010:0xffffffffc0601d8d
  Call Trace:
   <TASK>
   ? bpf_trampoline_6442515411+0x1a4/0x21b
   bpf_lsm_bprm_committed_creds+0x5/0x10
   security_bprm_committed_creds+0x5f/0x70
   begin_new_exec+0x2d6/0x410
   ...

We hit this in production when progs attached through trampolines got
detached while their hooks were busy, and it was independently found
with a fuzzer and KASAN.

Have the JITs emit a patchable nop in front of each prog call sequence
and record it in the image. When a prog is detached, patch its nop to a
jump over the call sequence. Progs that stay attached keep running for
the tasks that are in the image, and ip_after_call isn't needed anymore.

The task can be in any image that isn't freed yet, not only in the
current one. It sleeps in image I1 that calls S, P and Q, then P is
detached and the trampoline moves to image I2, then Q is detached and
its call is still in I1. So the trampoline keeps a list of its images
until they are freed, and detaching a prog patches its nop in all of
them. Images hold a reference on the trampoline for that long.

On riscv and loongarch a jump of any range takes several instructions,
and a task preempted in the middle of them could resume into half of the
new sequence. The nop is a single instruction there, patched to a near
branch through arch_bpf_trampoline_skip().

With the extra nops, BPF_MAX_TRAMP_LINKS progs no longer fit in a page
on x86 and arm64 (and already didn't on powerpc), so lower the limit
there like s390 does.

Fixes: e21aa34178 ("bpf: Fix fexit trampoline.")
Reported-by: Sechang Lim <rhkrqnwk98@gmail.com>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Florent Revest (Anthropic) <florent.revest@linux.dev>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20260926135605.1217928-3-florent.revest@linux.dev
Closes: https://lore.kernel.org/bpf/20260815071927.147049-1-zirajs7@gmail.com/
2026-09-29 05:54:16 +00:00
Florent Revest (Anthropic)
0fb5751a6e
bpf: Wait for an RCU tasks grace period before freeing trampoline progs
When a prog is detached from a trampoline, it is freed after an RCU
grace period, or an RCU tasks trace one if it is sleepable. This covers
the tasks that are running the prog, since the prog's enter helper takes
the matching read lock before the prog is called. On a preemptible
kernel, it doesn't cover a task that was preempted in the trampoline
just before the enter helper. That task holds no lock yet, and it calls
the prog after it was freed:

  BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_enter_recur+0x3a5/0x3f0
  Read of size 8 at addr ffffc90000055040 by task candidate/110
  CPU: 1 UID: 0 PID: 110 Comm: candidate Not tainted 7.3.0-rc2-00014-g15071f2a1263-dirty #2 PREEMPT(full)
  Call Trace:
   <TASK>
   __bpf_prog_enter_recur+0x3a5/0x3f0
   bpf_trampoline_6442509193+0x37/0xf1
   __x64_sys_futex+0x9/0x410
   do_syscall_64+0xb0/0x530
   ...

Wait for an RCU tasks grace period before the existing one when freeing
a prog that was linked to a trampoline. An RCU tasks grace period only
ends once the tasks that were preempted have run again, and
bpf_tramp_image_put() already relies on it to free the image. It doesn't
wait for tasks that sleep in the trampoline, the next commit takes care
of those.

Only progs that were linked to a trampoline can be called this way, so
bpf_trampoline_add_prog() marks them and other progs are still freed as
before.

Fixes: e21aa34178 ("bpf: Fix fexit trampoline.")
Reported-by: Junseo Lim <zirajs7@gmail.com>
Signed-off-by: Florent Revest (Anthropic) <florent.revest@linux.dev>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20260926135605.1217928-2-florent.revest@linux.dev
Closes: https://lore.kernel.org/bpf/aqdrwVpanH3WGurX@omen-arch/
2026-09-29 05:54:16 +00:00
Linus Torvalds
6f8319e3e9 10 hotfixes. 5 are cc:stable.
- Fix module loading incorrectly returning success after alloc_tag codetag
   setup failed.
 
 - Restore MADV_COLLAPSE semantics for shmem so forced collapse ignores the
   shmem THP/mTHP sysfs settings.
 
 - Make alloc_tag UAPI structure padding explicit.
 
 - Fix DAMON schemes unexpectedly stopping after quotas are disabled through
   the online parameter update interface.
 
 - Fix a false SW_TAGS KASAN invalid-access report when freeing vmapped task
   stacks.
 
 - Split the MEMORY MANAGEMENT - MEMORY POLICY AND MIGRATION MAINTAINERS
   entry into separate MIGRATION and NUMA PLACEMENT entries.
 
 - Move memory tiering maintenance under NUMA PLACEMENT.
 
 - Add Gregory Price as a NUMA PLACEMENT co-maintainer.
 
 - Add Heming Zhao as an ocfs2 reviewer.
 
 - Fix mmap_prepare() state being copied onto a merged VMA rather than only
   onto a newly allocated VMA.
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Merge tag 'mm-hotfixes-stable-2026-09-27-19-12' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM fixes from Andrew Morton:

 - Fix module loading incorrectly returning success after alloc_tag
   codetag setup failed

 - Restore MADV_COLLAPSE semantics for shmem so forced collapse ignores
   the shmem THP/mTHP sysfs settings

 - Make alloc_tag UAPI structure padding explicit

 - Fix DAMON schemes unexpectedly stopping after quotas are disabled
   through the online parameter update interface

 - Fix a false SW_TAGS KASAN invalid-access report when freeing vmapped
   task stacks

 - Split the MEMORY MANAGEMENT - MEMORY POLICY AND MIGRATION MAINTAINERS
   entry into separate MIGRATION and NUMA PLACEMENT entries

 - Move memory tiering maintenance under NUMA PLACEMENT

 - Add Gregory Price as a NUMA PLACEMENT co-maintainer

 - Add Heming Zhao as an ocfs2 reviewer

 - Fix mmap_prepare() state being copied onto a merged VMA rather than
   only onto a newly allocated VMA

* tag 'mm-hotfixes-stable-2026-09-27-19-12' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/vma: predicate setting mmap_prepare VMA fields on new vma alloc
  MAINTAINERS: add Heming Zhao as ocfs2 reviewer
  MAINTAINERS: make Gregory a co-maintainer of MEMORY MANAGEMENT - NUMA PLACEMENT
  MAINTAINERS: move memory tiering under MEMORY MANAGEMENT - NUMA PLACEMENT
  MAINTAINERS: split up MEMORY MANAGEMENT - MEMORY POLICY AND MIGRATION
  kasan: unpoison task stack below watermark only in generic mode
  mm/damon/core: don't skip damos_adjust_quota() while esz is not zero
  alloc_tag: avoid implicit padding in uapi
  mm: shmem: ignore sysfs configs for shmem forced collapse
  module: fix lost error code from codetag_load_module()
2026-09-28 20:11:31 -07:00
Linus Torvalds
104484baf7 workqueue: Fixes for v7.3-rc4
- Fix a NULL dereference in the flush dependency check when a worker flushes
   outside a work item, such as from the OOM path during worker creation.
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Merge tag 'wq-for-7.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue fix from Tejun Heo:

 - Fix a NULL dereference in the flush dependency check when a worker
   flushes outside a work item, such as from the OOM path during worker
   creation

* tag 'wq-for-7.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Fix NULL current_pwq deref in flush dependency check
2026-09-27 08:55:24 -07:00
Linus Torvalds
b1fa457bdd cgroup: Fixes for v7.3-rc4
- A cpuset partition could claim CPUs an ancestor partition already held
   exclusively. Restore the rejection an earlier change had turned into a
   warning.
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Merge tag 'cgroup-for-7.3-rc4-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fix from Tejun Heo:

 - A cpuset partition could claim CPUs an ancestor partition already
   held exclusively. Restore the rejection an earlier change had turned
   into a warning.

* tag 'cgroup-for-7.3-rc4-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup/cpuset: Return PERR_NOCPUS in remote_partition_enable() on subpartitions_cpus conflict
2026-09-27 08:51:45 -07:00
Linus Torvalds
7cdf91542e sched_ext: Fixes for v7.3-rc4
- The CPU topology helper for BPF schedulers took no buffer size, so its
   structure couldn't grow without breaking schedulers built against the
   older layout. Add a size argument.
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Merge tag 'sched_ext-for-7.3-rc4-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

Pull sched_ext fix from Tejun Heo:

 - The CPU topology helper for BPF schedulers took no buffer size, so
   its structure couldn't grow without breaking schedulers built against
   the older layout. Add a size argument.

* tag 'sched_ext-for-7.3-rc4-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
  sched_ext: Add a size argument to scx_bpf_cid_topo() so struct scx_cid_topo can grow
2026-09-27 08:50:25 -07:00
Linus Torvalds
673dab7eac Scheduler fixes:
- Fix LLC mis-scheduling bugs (Tim Chen, Lu Wang)
 
  - Fix cache-grouping related scheduling statistics UAF bugs (Tim Chen)
 
  - Skip kernel threads for cache aware scheduling to rubustify the code
    (Chen Yu)
 
  - Refresh LLC capacity across CPU hotplug, to fix capacity
    underestimation bug (Davi Chaves Azevedo)
 
  - Account PSI IRQ time to the execution context, not the scheduling
    context, to fix proxy scheduling accounting bug (Zhan Xusheng)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-urgent-2026-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:

 - Fix LLC mis-scheduling bugs (Tim Chen, Lu Wang)

 - Fix cache-grouping related scheduling statistics UAF bugs (Tim Chen)

 - Skip kernel threads for cache aware scheduling to rubustify the code
   (Chen Yu)

 - Refresh LLC capacity across CPU hotplug, to fix capacity
   underestimation bug (Davi Chaves Azevedo)

 - Account PSI IRQ time to the execution context, not the scheduling
   context, to fix proxy scheduling accounting bug (Zhan Xusheng)

* tag 'sched-urgent-2026-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Account PSI IRQ time to the execution context, not the scheduling context
  sched/cache: Refresh LLC capacity across CPU hotplug, to fix capacity underestimation bug
  sched/cache: Skip kernel threads for cache aware scheduling to rubustify the code
  sched/cache: Introduce task_struct->sched_cache_grp to fix UAF
  sched/cache: Decouple sched_cache_group from mm to fix UAF
  sched/cache: Honor migrate_llc_task semantics in active load balance, to fix LLC mis-scheduling bug
  sched/cache: Keep nr_pref_llc_running in the runnable domain, to fix LLC mis-scheduling bug
2026-09-27 08:24:16 -07:00
Linus Torvalds
5ccda18d1b Perf events fixes:
- Fixes for KVM guest PEBS virtualization (Sean Christopherson)
 
  - Fixes for various Intel PMUs related to PEBS data-source
    (Dapeng Mi)
 
  - Fix Intel Panther Cove event scheduling constraints (Dapeng Mi)
 
  - Fix Intel DMR/NVL OMR extra registers event scheduling (Dapeng Mi)
 
  - Rename two confusingly named PMU attributes (Dapeng Mi)
 
  - Fix a refcount leak in attach_perf_ctx_data() (Namhyung Kim)
 
  - Fix NULL pointer dereference crash in __perf_pmu_sched_task()
    (Puranjay Mohan)
 
  - Fix CPU-wide event scheduling (Puranjay Mohan)
 
  - Fix x86 LBR branch entry generation (Puranjay Mohan)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-urgent-2026-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf events fixes from Ingo Molnar:

 - Fixes for KVM guest PEBS virtualization (Sean Christopherson)

 - Fixes for various Intel PMUs related to PEBS data-source (Dapeng Mi)

 - Fix Intel Panther Cove event scheduling constraints (Dapeng Mi)

 - Fix Intel DMR/NVL OMR extra registers event scheduling (Dapeng Mi)

 - Rename two confusingly named PMU attributes (Dapeng Mi)

 - Fix a refcount leak in attach_perf_ctx_data() (Namhyung Kim)

 - Fix NULL pointer dereference crash in __perf_pmu_sched_task()
   (Puranjay Mohan)

 - Fix CPU-wide event scheduling (Puranjay Mohan)

 - Fix x86 LBR branch entry generation (Puranjay Mohan)

* tag 'perf-urgent-2026-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fill branch entries with a single assignment
  perf/core: Run sched_task() for PMUs with only CPU-wide events
  perf/core: Fix NULL pmu_ctx passed to pmu->sched_task()
  perf/core: Fix a refcount leak in attach_perf_ctx_data()
  perf/x86/intel: Rename NVL offcore_rsp attribute to offmodule_rsp
  perf/x86/intel: Rename DMR offcore_rsp attribute to offmodule_rsp
  perf/x86/intel: Fix precise OMR event scheduling for DMR/NVL
  perf/x86/intel: Constrain Panther Cove UOPS_DISPATCHED events to PMCs 0-3
  perf/x86/intel: Delete dead NVL PEBS data-source initcall
  perf/x86/intel: Fix Panther Cove PEBS data-source snoop states
  perf/x86/intel: Remove incorrect Panther Cove PEBS data-source constraints
  perf/x86/intel: Remove incorrect LionCove PEBS data-source constraints
  perf/x86/intel: Update arw_latency_data() mem-op direction handling
  perf/x86/intel: Fix DKT PEBS load/store direction for latency events, to fix sample classification
  perf/x86/intel: Fix CMT PEBS load/store direction for latency events, to fix sample classification
  perf/x86/intel: Fix GRT PEBS load/store direction for latency events, to fix sample classification
  perf/x86/intel: Make @data a mandatory param for intel_guest_get_msrs()
  perf/x86/intel: Don't pointlessly context switch DS_AREA (and PEBS config) if PEBS is unused
  perf/x86/intel: Don't write PEBS_ENABLED on host<=>guest xfers if CPU has PEBS isolation, to fix stuck PEBS_ENABLED
  perf/x86/intel: Ensure KVM guest PEBS path doesn't set unwanted PERF_GLOBAL_CTRL bits
2026-09-27 08:15:58 -07:00
Pavankumar Kondeti
db6365ced4 workqueue: Fix NULL current_pwq deref in flush dependency check
check_flush_dependency() uses current_wq_worker() to determine whether
the caller is a workqueue worker and then dereferences worker->current_pwq
to test whether the current workqueue is WQ_MEM_RECLAIM.

current_wq_worker() only means that %current has PF_WQ_WORKER set. A
kworker can reach check_flush_dependency() while it is not executing a
work item. One such path is worker_thread() acting as the pool manager,
where create_worker() does GFP_KERNEL allocation and the allocation path
invokes the OOM notifier. In that state worker->current_pwq is NULL
because current_pwq is set only by process_one_work() and cleared again
after the work function returns.

[  416.760634][  T375] Call trace:
[  416.760638][  T375]  check_flush_dependency+0x80/0x120 (P)
[  416.760648][  T375]  __flush_work+0x98/0x224
[  416.760657][  T375]  flush_work+0x30/0x44
[  416.760665][  T375]  ...
[  416.760710][  T375]  blocking_notifier_call_chain+0x58/0xa0
[  416.760719][  T375]  out_of_memory+0xb4/0x458
[  416.760730][  T375]  __alloc_pages_may_oom+0x11c/0x1a8
[  416.760739][  T375]  __alloc_pages_slowpath+0x314/0x46c
[  416.760746][  T375]  __alloc_frozen_pages_noprof+0x110/0x1a4
[  416.760753][  T375]  new_slab+0x12c/0x484
[  416.760759][  T375]  ___slab_alloc+0x7a8/0xc7c
[  416.760765][  T375]  __slab_alloc+0x74/0xd8
[  416.760772][  T375]  __kmalloc_cache_node_noprof+0x2ac/0x304
[  416.760779][  T375]  alloc_worker+0x28/0x60
[  416.760785][  T375]  create_worker+0x4c/0x20c
[  416.760790][  T375]  worker_thread+0xe8/0x2b8
[  416.760796][  T375]  kthread+0x1a8/0x200
[  416.760805][  T375]  ret_from_fork+0x10/0x20

Guard the WQ_MEM_RECLAIM-worker warning with worker->current_pwq. If the
kworker is not currently executing a work item, there is no current
workqueue to diagnose with that warning. The PF_MEMALLOC warning is left
unchanged so explicit reclaim context flushing a !WQ_MEM_RECLAIM target
is still reported.

Fixes: fca839c00a ("workqueue: warn if memory reclaim tries to flush !WQ_MEM_RECLAIM workqueue")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Pavankumar Kondeti <pavan.kondeti@oss.qualcomm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2026-09-26 22:18:50 -10:00
Hao Ge
c79cf15eb3 module: fix lost error code from codetag_load_module()
If codetag_load_module() fails, err is not set to reflect the failure
and load_module() returns 0 after the module has been torn down.

Also, if the module is a livepatch, mod->klp_info allocated by
copy_module_elf() leaks on this error path.  Free it via a new
livepatch_cleanup label.

Link: https://lore.kernel.org/20260827030503.49171-1-hao.ge@linux.dev
Fixes: 044d2aee6c ("alloc_tag: handle module codetag load errors as module load failures")
Signed-off-by: Hao Ge <hao.ge@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Sashiko <sashiko-bot@kernel.org>
Suggested-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Bradley Morgan <brads@mainlining.org>
Cc: Aaron Tomlin <atomlin@atomlin.com>
Cc: Luis Chamberalin <mcgrof@kernel.org>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: <stable@vger.kernel.org>
2026-09-26 13:55:09 -07:00
Tejun Heo
94480606a6 sched_ext: Add a size argument to scx_bpf_cid_topo() so struct scx_cid_topo can grow
scx_bpf_cid_topo() copies struct scx_cid_topo into a buffer the BPF program
sized from its own vmlinux.h while the verifier sizes the write from the
running kernel's BTF. The struct may grow and each growth then breaks every
scheduler built against the older layout, rejected at load or written past
its buffer. This is the usual hole for a struct handed to BPF, closed
elsewhere with a size argument, and it was missed here.

Take the buffer size, copy the smaller of it and the kernel's struct and set
the rest to -1. Accesses to the copy are CO-RE relocated, so the struct can
grow by appending fields, which its comment now states. The kfunc changes in
place: the cid interface is still being finalized and no released scheduler
uses the current form.

Fixes: e9b55af47e ("sched_ext: Add topological CPU IDs (cids)")
Cc: stable@vger.kernel.org # v7.2+
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-09-26 10:09:12 -10:00
Hui Peng
31c88350b7 cgroup/cpuset: Return PERR_NOCPUS in remote_partition_enable() on subpartitions_cpus conflict
When a remote partition is created underneath an existing local partition
via a non-partition (PRS_MEMBER) intermediate cgroup, update_prstate() sees
parent->partition_root_state == PRS_MEMBER and calls
remote_partition_enable().

Commit 86888c7bd1 ("cgroup/cpuset: Add warnings to catch inconsistency
in exclusive CPUs") replaced the cpumask_intersects(tmp->new_cpus,
subpartitions_cpus) error check in remote_partition_enable() with
WARN_ON_ONCE(). As a result, remote_partition_enable() emits a warning
and proceeds to enable the remote partition on CPUs that are already
owned by the ancestor local partition in subpartitions_cpus.

This can be reproduced on Linux 7.3.0-rc3 with:

  mkdir -p /tmp/cg1
  mount -t cgroup2 none /tmp/cg1
  echo "+cpuset" > /tmp/cg1/cgroup.subtree_control

  mkdir /tmp/cg1/A
  echo 1 > /tmp/cg1/A/cpuset.cpus
  echo 1 > /tmp/cg1/A/cpuset.cpus.exclusive
  echo root > /tmp/cg1/A/cpuset.cpus.partition
  echo "+cpuset" > /tmp/cg1/A/cgroup.subtree_control

  mkdir /tmp/cg1/A/B
  echo 1 > /tmp/cg1/A/B/cpuset.cpus
  echo 1 > /tmp/cg1/A/B/cpuset.cpus.exclusive
  echo "+cpuset" > /tmp/cg1/A/B/cgroup.subtree_control

  mkdir /tmp/cg1/A/B/D
  echo 1 > /tmp/cg1/A/B/D/cpuset.cpus
  echo 1 > /tmp/cg1/A/B/D/cpuset.cpus.exclusive
  echo root > /tmp/cg1/A/B/D/cpuset.cpus.partition

which triggers:

  WARNING: kernel/cgroup/cpuset.c:1594 at remote_partition_enable+0x1c1/0x300

and leaves both /tmp/cg1/A and /tmp/cg1/A/B/D as active root partitions
claiming exclusive CPU 1.

Fix this by returning PERR_NOCPUS when tmp->new_cpus intersects
subpartitions_cpus in remote_partition_enable(), matching the error code
used by remote_cpus_update() for the same subpartitions_cpus conflict, and
add a regression test case to
tools/testing/selftests/cgroup/test_cpuset_prs.sh.

Tested in QEMU on Linux 7.3.0-rc3 using the reproducer above and
tools/testing/selftests/cgroup/test_cpuset_prs.sh.

Fixes: 86888c7bd1 ("cgroup/cpuset: Add warnings to catch inconsistency in exclusive CPUs")
Suggested-by: Guopeng Zhang <guopeng.zhang@linux.dev>
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Hui Peng <benquike@gmail.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2026-09-26 08:07:26 -10:00
Linus Torvalds
efb27d4767 Probes fixes for v7.3-rc4:
- kprobes: Fix permanent hang when flushing the kprobe optimizer
   Fix a deadlock when disabling kprobe optimization via sysctl or debugfs
   where flushers hung waiting for optimizer_completion. Replaced the
   completion with an optimizer_passes counter and wait_var_event_mutex()
   under kprobe_mutex so concurrent flushers can wait and wake up safely.
 
 - fprobe: Terminate the fgraph_data list when the reservation is not filled
   Fix an issue where unused shadow stack data left uninitialized by
   fprobe_fgraph_entry() was misparsed as stale fprobe headers on return.
   Explicitly write a zero word to terminate the list and update
   read_fprobe_header() to handle the zeroed slot properly.
 
 - ftracetest: Fix unique symbol check in kprobe_non_uniq_symbol.tc
   Fix false test failures in kprobe_non_uniq_symbol.tc on architectures
   like s390 where a symbol exists once in core kernel but also in modules.
   Anchor the /proc/kallsyms search regex to the end of the line so that
   module symbols are not incorrectly counted.
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Merge tag 'probes-fixes-v7.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probe fixes from Masami Hiramatsu:

 - kprobes: Fix permanent hang when flushing the kprobe optimizer

   Fix a deadlock when disabling kprobe optimization via sysctl or
   debugfs where flushers hung waiting for optimizer_completion.
   Replaced the completion with an optimizer_passes counter and
   wait_var_event_mutex() under kprobe_mutex so concurrent flushers can
   wait and wake up safely.

 - fprobe: Terminate the fgraph_data list when the reservation is not
   filled

   Fix an issue where unused shadow stack data left uninitialized by
   fprobe_fgraph_entry() was misparsed as stale fprobe headers on
   return. Explicitly write a zero word to terminate the list and update
   read_fprobe_header() to handle the zeroed slot properly.

 - ftracetest: Fix unique symbol check in kprobe_non_uniq_symbol.tc

   Fix false test failures in kprobe_non_uniq_symbol.tc on architectures
   like s390 where a symbol exists once in core kernel but also in
   modules. Anchor the /proc/kallsyms search regex to the end of the
   line so that module symbols are not incorrectly counted.

* tag 'probes-fixes-v7.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  kprobes: Fix permanent hang when flushing the kprobe optimizer
  fprobe: Terminate the fgraph_data list when the reservation is not filled
  selftests/ftrace: Fix unique symbol check in kprobe_non_uniq_symbol.tc
2026-09-26 08:36:29 -07:00
Jérémy Jean
aa650d87a4 audit: fix exe mark UAF in kill_rules()
kill_rules() removes mixed AUDIT_DIR and AUDIT_EXE rules when an audit
tree is pruned. It drops entry->rule.exe before removing the rule from
the RCU-visible filter lists.

After a rule has been installed with AUDIT_ADD_RULE, which requires
CAP_AUDIT_CONTROL, removing the watched directory can race with another
task that is still evaluating the rule. In that case, fsnotify can free
the executable mark before the reader reaches audit_mark_compare(),
causing a use-after-free.

KASAN reports:

    BUG: KASAN: slab-use-after-free in audit_mark_compare+0x8d/0xa0

Unlink the published rules from the RCU-visible lists and retain them
on tree->rules for cleanup. If any rule has an executable mark, wait for
a single RCU grace period before removing the marks and scheduling the
entries for freeing. Otherwise, call_rcu() already provides the required
deferred freeing without a synchronous wait.

Cc: stable@vger.kernel.org
Fixes: 34d99af52a ("audit: implement audit by executable")
Assisted-by: Codex:gpt-5
Signed-off-by: Jérémy Jean <Jeremy.Jean@oss.cyber.gouv.fr>
Reviewed-by: Ricardo Robaina <rrobaina@redhat.com>
Tested-by: Ricardo Robaina <rrobaina@redhat.com>
Reviewed-by: Bradley Morgan <brads@mainlining.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2026-09-25 16:18:51 -04:00
Kumar Kartikeya Dwivedi
ab39974240
bpf: Hold map BTF for the memory allocator destructor record
bpf_ma_set_dtor() duplicates map->record so that the bpf_mem_alloc
destructor can release the special fields of hash and rhash map elements
once the allocator frees them for good. btf_record_dup() only acquires
references on kernel and module BTF. Fields whose types live in the map
BTF keep pointing into it: a kptr to a local type refers to map->btf,
and a list_head or rb_root field carries a value_rec owned by the struct
meta table of map->btf.

That borrowed state can outlive the map. When RCU callbacks are still in
flight, bpf_mem_alloc_destroy() copies the allocator and defers the final
drain, together with the destructor context, to a workqueue.
bpf_map_free() then frees map->record and drops the map's BTF reference
as soon as map_free() returns. Once the program that loaded the BTF is
gone as well, the BTF is freed while the worker still uses the
duplicate. The worker dereferences it through btf_is_kernel() and
btf_find_struct_meta() in bpf_obj_free_fields() when destroying elements
that were freed under RCU, and through btf_is_kernel() in
btf_record_free() when releasing the context itself:

  BUG: KASAN: slab-use-after-free in btf_is_kernel+0x19/0x30
  Read of size 1 at addr ffff88811505dce8 by task kworker/u16:2/50
  Workqueue: events_unbound free_mem_alloc_deferred
  Call Trace:
   btf_is_kernel+0x19/0x30
   btf_record_free+0xc7/0xf0
   htab_dtor_ctx_free+0x1a/0x30
   free_mem_alloc_no_barrier+0x39/0x230
   free_mem_alloc_deferred+0x2a/0x40
   process_scheduled_works+0x5ce/0x9d0
   worker_thread+0x42a/0x5e0
   kthread+0x1f5/0x230
   ret_from_fork+0x1dd/0x390
   ret_from_fork_asm+0x1a/0x30

  Allocated by task 358:
   __kmalloc_cache_noprof+0x287/0x510
   btf_new_fd+0xf7/0x3d0
   __sys_bpf+0x487/0x840

  Freed by task 0:
   kfree+0x186/0x560
   rcu_core+0x6f6/0xd40

Freeing a map that still holds more elements than the allocator's high
watermark is enough to get there, because the bulk free during teardown
queues the RCU callback that makes bpf_mem_alloc_destroy() defer.
Non-preallocated hash maps and resizable hash maps both register the
destructor and are affected alike.

Keep one reference on the map BTF in the destructor context. Every
non-kernel pointer in the duplicated record is either map->btf or memory
owned by it, so a single reference covers kptrs, list heads, and rb
roots, and mirrors what bpf_map_meta_alloc() does for the duplicated
record of an inner map. Release it only after the duplicated record has
been freed: the worker is preemptible and not in an RCU read-side
critical section, so dropping the last reference first would let the
BTF be freed while btf_record_free() still reads its fields.

Fixes: 1df97a7453 ("bpf: Register dtor for freeing special fields")
Reported-by: Yuan Chen <chenyuan@kylinos.cn>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260901062845.1379760-3-chenyuan_fl@163.com
Link: https://patch.msgid.link/20260925064652.2261885-1-memxor@gmail.com
2026-09-25 17:29:04 +00:00
Linus Torvalds
4ba51ef66a Power management fix for 7.3-rc5
Address a hibernation regression introduced during the 7.2 development
 cycle that causes the image memory preallocation to deadlock if it
 depends on frozen kernel threads (Florian Schmaus).
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Merge tag 'pm-7.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fix from Rafael Wysocki:
 "Address a hibernation regression introduced during the 7.2 development
  cycle that causes the image memory preallocation to deadlock if it
  depends on frozen kernel threads (Florian Schmaus)"

* tag 'pm-7.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: hibernate: Freeze kernel threads after image preallocation
2026-09-25 09:47:05 -07:00
Andrea Parri
5bfa9f1a9d kprobes: Fix permanent hang when flushing the kprobe optimizer
Writing 0 to /proc/sys/debug/kprobes-optimization while a kprobe is
jump-optimized never returns. The writer sleeps in D state forever with
kprobe_sysctl_mutex held, so any later read or write of that sysctl
hangs as well. For example, with vfs_read+9 as an optimizable address
in this build:

  # cd /sys/kernel/tracing
  # echo 'p:myprobe vfs_read+9' >> kprobe_events
  # echo 1 > events/kprobes/myprobe/enable
  # # wait until /sys/kernel/debug/kprobes/list shows [OPTIMIZED]
  # echo 0 > /proc/sys/debug/kprobes-optimization

  INFO: task sh:246 blocked for more than 10 seconds.
  Call Trace:
   <TASK>
   __schedule+0x1176/0x4f70
   schedule+0xdc/0x2c0
   schedule_timeout+0x17b/0x260
   wait_for_completion+0x173/0x3c0
   wait_for_kprobe_optimizer_locked+0xbc/0x130
   proc_kprobes_optimization_handler+0x156/0x1b0
   proc_sys_call_handler+0x324/0x490
   vfs_write+0x52d/0xfe0
   ksys_write+0xff/0x200
   do_syscall_64+0x106/0x630
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   </TASK>
  ...
  INFO: task cat:265 is blocked on a mutex likely owned by task sh:246.

wait_for_kprobe_optimizer_locked() reinitializes optimizer_completion,
asks the optimizer thread to flush and sleeps in wait_for_completion().
The thread drains the (un)optimizing lists, but calls complete() only
if completion_done() is true, i.e. if the completion is already done,
which never happens while someone waits. disarm_all_kprobes() and
kprobe_trace_self_tests_init() wait the same way.

Calling complete() unconditionally would not be enough: the waiter
drops kprobe_mutex while it sleeps, and nothing else serializes the
sysctl handler against the debugfs "enabled" file. A second flusher
that still finds the lists non-empty, e.g. because a disabled probe is
queued for unoptimizing, reinitializes the completion under the first:

  sysctl write                      debugfs "enabled" write
  unoptimize_all_kprobes()
    wait_for_kprobe_optimizer_locked()
      init_completion(c)
      mutex_unlock(&kprobe_mutex)
      wait_for_completion(c)
                                    disarm_all_kprobes()
                                      wait_for_kprobe_optimizer_locked()
                                        init_completion(c)
                                          // c->wait is reset, the first
                                          // waiter is off the queue
                                        mutex_unlock(&kprobe_mutex)
                                        wait_for_completion(c)
  kprobe_optimizer()
    complete(c)
      // wakes the debugfs writer only

where c is &optimizer_completion. Lining up the two writes during an
optimizer pass loses the sysctl writer this way.

Replace the completion with a counter of optimizer passes, bumped at the
end of each pass and signalled with wake_up_var_locked(), both under
kprobe_mutex. A flusher samples the count and waits with
wait_var_event_mutex(), which drops kprobe_mutex only while sleeping, so
a new count means a whole pass ran in the meantime. Nothing is
reinitialized, so several flushers can sleep in the wait at once.

Link: https://lore.kernel.org/all/20260924092142.199198-1-parri.andrea@gmail.com/

Fixes: 73c12f2094 ("kprobes: Use dedicated kthread for kprobe optimizer")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-09-25 23:35:23 +09:00
Alexei Starovoitov
ad139384ec
bpf: Fix overflow of jump offset in constant blinding
bpf_jit_blind_insn() rewrites 'if rX op imm goto off' into:

  AX = imm ^ rnd
  AX ^= rnd
  if rX op AX goto off

and subtracts 2 from off when the jump is backward. off is s16, so
-32767 and -32768 wrap and the jump goes 32767 insns forward, past the
end of the prog. The jump is inside the patch, hence bpf_adj_branches()
doesn't check it. The kernel crashes when such prog runs with
bpf_jit_harden=2.

Return -ERANGE in such case. bpf_jit_blind_constants() fails the same
way when blinding of other insns moves a jump out of range.

Fixes: 4f3446bb80 ("bpf: add generic constant blinding for use in jits")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260924182353.277516-1-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
2026-09-25 04:43:27 +02:00
Linus Torvalds
ee9c669f9b sched_ext: Fixes for v7.3-rc4
- A task reenqueued while its dispatch was still completing had its queued
   state clobbered by the dispatcher, dropping every later dispatch of the
   task. Wait for the in-flight dispatch to settle first.
 
 - A wakeup activation on another CPU marked the destination runqueue as
   mid-wakeup, stranding a pending local reenqueue. If the scheduler was
   unloaded first, the stale request pointed into freed memory that the next
   scheduler dereferenced.
 
 - ops.dequeue() ran with the source dispatch queue's lock held, so a
   scheduler iterating that queue from the callback deadlocked the CPU.
 
 - Schedulers with their own CPU ID mapping had no way to learn a task's
   initial CPU mask and rebuilt it themselves, which went wrong across
   sub-scheduler enable and re-home. Pass it to ops.enable().
 
 - A bypass dispatch event counter missed the dispatches made by the
   end-of-dispatch fallback and under-reported.
 
 - Selftests for the dequeue locking and initial mask changes.
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Merge tag 'sched_ext-for-7.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

Pull sched_ext fixes from Tejun Heo:

 - A task reenqueued while its dispatch was still completing had its
   queued state clobbered by the dispatcher, dropping every later
   dispatch of the task. Wait for the in-flight dispatch to settle
   first

 - A wakeup activation on another CPU marked the destination runqueue as
   mid-wakeup, stranding a pending local reenqueue. If the scheduler was
   unloaded first, the stale request pointed into freed memory that the
   next scheduler dereferenced

 - ops.dequeue() ran with the source dispatch queue's lock held, so a
   scheduler iterating that queue from the callback deadlocked the CPU

 - Schedulers with their own CPU ID mapping had no way to learn a task's
   initial CPU mask and rebuilt it themselves, which went wrong across
   sub-scheduler enable and re-home. Pass it to ops.enable()

 - A bypass dispatch event counter missed the dispatches made by the
   end-of-dispatch fallback and under-reported

 - Selftests for the dequeue locking and initial mask changes

* tag 'sched_ext-for-7.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
  sched_ext: Count SCX_EV_SUB_BYPASS_DISPATCH in the dispatch fallback
  selftests/sched_ext: Check the cmask cid-form ops.enable() receives
  sched_ext: Pass the initial cmask to cid-form ops.enable()
  selftests/sched_ext: Test that ops.dequeue() can iterate the consumed DSQ
  sched_ext: Don't run ops.dequeue() with a DSQ lock held
  sched_ext: Derive SCX_RQ_IN_WAKEUP from the core enqueue flags
  sched_ext: Wait for SCX_OPSS_DISPATCHING before reenqueueing a task
2026-09-24 15:04:11 -07:00
Linus Torvalds
e8dfd03a1c cgroup: Fixes for v7.3-rc4
- With local event accounting, a fork rejected by the pids controller
   updated pids.events without notifying its pollers.
 
 - A cgroup selftest failed to compile with fortification enabled because
   an O_TMPFILE open lacked its mode argument.
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Merge tag 'cgroup-for-7.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fixes from Tejun Heo:

 - With local event accounting, a fork rejected by the pids controller
   updated pids.events without notifying its pollers

 - A cgroup selftest failed to compile with fortification enabled
   because an O_TMPFILE open lacked its mode argument

* tag 'cgroup-for-7.3-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup/pids: Restore pids.events notifications in local mode
  selftests: cgroup: give the O_TMPFILE open in get_temp_fd() a mode
2026-09-24 14:26:12 -07:00
Guopeng Zhang
1765a153d9 cgroup/pids: Restore pids.events notifications in local mode
A fork rejected by the pids controller increments the counter reported by
pids.events. When local event accounting is selected, however, pids_event()
returns after notifying only events_local_file, leaving pids.events pollers
asleep.

On legacy hierarchies, pids.events.local does not exist. With
pids_localevents, pids.events reports the same local counter. In both
cases, pids.events changes without generating a notification.

This can be reproduced with a pids_localevents mount:

    mkdir /tmp/test
    mount -t cgroup2 -o pids_localevents none /tmp/test
    mkdir /tmp/test/t
    echo 1 > /tmp/test/t/pids.max
    cat /tmp/test/t/pids.events                 # max 0
    timeout 3 inotifywait -e modify /tmp/test/t/pids.events &
    sh -c 'echo $$ > /tmp/test/t/cgroup.procs; (true &)' 2>/dev/null
    wait
    cat /tmp/test/t/pids.events                 # max 1

Without this patch, inotifywait times out without reporting an event.
Notify pids.events before returning from the local event path.

Fixes: 3f26a885a0 ("cgroup/pids: Add pids.events.local")
Cc: stable@vger.kernel.org # v6.11+
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
2026-09-24 06:22:11 -10:00
Linus Torvalds
5fc5768c7c bpf-fixes
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Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Pull bpf fixes from Alexei Starovoitov:

 - Fix bpf_skb_change_tail() to drop the checksum offload instead of
   rejecting the trim of CHECKSUM_PARTIAL skbs (Daniel Borkmann)

 - Add KF_PERFMON kfunc flag and require CAP_PERFMON for kfuncs that
   read arbitrary memory and for untrusted read-only memory reads
   (Daniel Borkmann)

 - Clear scalar delta on narrowing stack spill (Daniel Borkmann)

 - Set up the frame pointer for the exception callback in arm64 JIT, and
   zero-fill other CPUs when BPF_F_CPU update creates a per-cpu hash
   element (Donggeun Yoo)

 - Various fixes (Emil Tsalapatis):
     - Fix bounds check underflow for skb-backed dynptrs
     - Fix rx_queue_mapping context access code generation in bpf_sock
     - Reject packet pointer arguments to subprogs that may mutate the
       packet
     - Reject ALU instructions that see arena and non-arena operands on
       different code paths

 - Fix copied_seq double-counting on sockmap self-redirect
   (Geliang Tang)

 - Fix divide-by-zero in btf_struct_walk() on a flexible array of
   zero-sized elements, fix out-of-bounds read of rtt_min in sock_ops
   (Jiayuan Chen)

 - Fix bpf_sock_destroy() out-of-bounds read of sk_protocol on TIME_WAIT
   and request socks, and sleeping under RCU when destroying a listener
   with pending children (Jiayuan Chen)

 - Fix JEQ/JNE with immediate operand in MIPS32 JIT and missing zero
   extension of BSWAP 16/32 in MIPS64 JIT (Johan Almbladh)

 - Avoid soft lockup in htab lookup[_and_delete] batch operations on
   large maps (Jose Fernandez)

 - Various fixes (Kumar Kartikeya Dwivedi):
     - Verify global subprogs in each sleepability context they are
       called from
     - Make post-verification instruction rewrites killable
     - Preserve packet pointer displacement in regsafe()
     - Apply CO-RE relocations before subprogram validation, restrict
       CO-RE poisoning to relocatable instructions, and reject truncated
       ldimm64 CO-RE relocations in libbpf
     - Assign lock identity to callback map values
     - Compare stack frames in regs_exact()
     - Bound ownership depth through local kptrs and graph roots

 - Fix u32 overflow in map batch operations when the map size exceeds
   4GB (Masoud Aghasi)

 - Fix UAF in bpf memalloc due to concurrent consumption of ttrace lists
   in alloc_bulk() (Pu Lehui)

 - Allow gotox as the terminal instruction of a program or a subprogram
   (Siddharth Chintamaneni)

 - Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL, skip unsettled links
   in link iterator, and reject dev-bound-only programs on other devices
   (Weiming Shi)

 - Reject non-negative stack offsets in stack_slot_obj_get_spi()
   (Xu Yunxiang)

 - Check params size before reading reserved fields in
   bpf_crypto_ctx_create() (Yuqi Xu)

 - Reject max_entries > INT_MAX in sock_map_alloc() (Zhao Gongyi)

 - Use a 32-bit compare in xsk_map_gen_lookup() (Zhiling Zou)

 - Use kvfree() in xdp_test_run_teardown() (Zhixing Chen)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (58 commits)
  selftests/bpf: Test per-cpu initialization of a BPF_F_CPU created element
  bpf: Zero-fill other CPUs when BPF_F_CPU creates a per-cpu hash element
  bpf: Fix BSWAP 32 and 16 on MIPS64
  bpf: Fix immediate JMP JEQ/JNE on MIPS32
  bpf: Reject dev-bound-only programs on other devices
  bpf, sockmap: Reject max_entries > INT_MAX in sock_map_alloc
  selftests/bpf: Test for mixed arena/nonarena code paths
  bpf: Prevent variable arena/non-arena register contents
  selftests/bpf: Test rejection of pkt args to mutating subprogs
  bpf: Reject pkt arguments in mutating subprogs
  selftests/bpf: Add selftests for rx_queue_mapping context access
  bpf: Fix bpf_sock context code generation
  selftests/bpf: Test dynptr slices past end of skb
  bpf: Fix bounds check for skb-backed dynptrs
  selftests/bpf: Reject iterator destruction through fp+0
  bpf: Reject non-negative offsets in stack_slot_obj_get_spi()
  bpf: Check params size before reading reserved fields
  selftests/bpf: Check local object ownership depth
  bpf: Bound ownership depth through local kptrs and graph roots
  selftests/bpf: Cover frame changes in bounded loops
  ...
2026-09-24 08:25:26 -07:00
Donggeun Yoo
c3a66e5f5b
bpf: Zero-fill other CPUs when BPF_F_CPU creates a per-cpu hash element
pcpu_init_value() initializes the per-cpu area of a newly created
[lru_]percpu_hash element.  The area is recycled, so when the value
comes from a BPF program (onallcpus == false) it writes the running
CPU's slot and zeroes the rest.

bpf_percpu_hash_update() passes onallcpus == true, which delegates to
pcpu_copy_value().  pcpu_copy_value() writes only the CPU named in
map_flags when BPF_F_CPU is set, so on the create path the other slots
keep the recycled element's values:

  update(k1, 0xdeadc0de, BPF_F_ALL_CPUS)  every CPU holds 0xdeadc0de
  delete(k1)                              element back on the freelist
  update(k2, 0xc0ffee, BPF_F_CPU | 0)     creates, writes CPU 0 only
  lookup(k2)                              CPU 0 0xc0ffee, rest 0xdeadc0de

Zero-fill the other CPUs on that arm too.

Fixes: c6936161fd ("bpf: Add BPF_F_CPU and BPF_F_ALL_CPUS flags support for percpu_hash and lru_percpu_hash maps")
Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20260924102321.2120434-2-donggeunyoo.kernel@gmail.com
2026-09-24 14:24:51 +00:00
Zhan Xusheng
a0bb6fac53 sched/core: Account PSI IRQ time to the execution context, not the scheduling context
psi_account_irqtime() has two callers which share rq->psi_irq_time, and
they disagree about the context: __schedule() passes the outgoing rq->curr,
sched_tick() passes rq->donor.  Under proxy execution the donor is blocked
on a mutex while rq->curr burns the CPU.

The tick charges PSI_IRQ_FULL to the donor's cgroup and advances the
timestamp, so the call from __schedule() then finds delta <= 0 and charges
nothing.  The delta is not counted twice, it lands on the wrong cgroup.

Pass rq->curr, which is what the call read before commit af0c8b2bf6
("sched: Split scheduler and execution contexts") renamed 'curr' to
'donor' across sched_tick().  Without CONFIG_SCHED_PROXY_EXEC the two rq
members are a union, so this only changes anything where that option is set,
and it depends on EXPERT.

Fixes: af0c8b2bf6 ("sched: Split scheduler and execution contexts")
Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://patch.msgid.link/20260918132915.1236312-1-zhanxusheng@xiaomi.com
2026-09-24 10:32:50 +02:00
Liang Luo
4409a85735 sched_ext: Count SCX_EV_SUB_BYPASS_DISPATCH in the dispatch fallback
When a descendant scheduler enters bypass mode, its tasks are parked in
the bypass DSQs of the nearest non-bypassing ancestor, which is then
responsible for running them. On behalf of such a non-bypassing host,
scx_dispatch_sched() consumes those bypass DSQs from two places: the
attempt made every SCX_BYPASS_HOST_NTH dispatches, and the
end-of-dispatch fallback that keeps the CPU from going idle while
bypassed descendants still have tasks queued.

The former increments SCX_EV_SUB_BYPASS_DISPATCH but the latter does
not, even though both perform the same scx_consume_dispatch_q() on the
same bypass DSQ. The descendant bypass dispatches done by the fallback
are therefore missing from the counter exposed via sysfs,
scx_dump_state() and the scx_bpf_events() kfunc, which under-reports the
actual number of such dispatches.

Add the missing __scx_add_event() so the fallback counts them too. When
@sch itself is bypassing, scx_dispatch_sched() takes the earlier
self-bypass branch and returns before reaching these host paths; that
mode is accounted for by SCX_EV_BYPASS_DISPATCH at enqueue time and is
intentionally left unchanged.

Fixes: 025b1bd419 ("sched_ext: Implement hierarchical bypass mode")
Signed-off-by: Liang Luo <luoliang@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
2026-09-23 08:16:10 -10:00
Puranjay Mohan
3d8d741009 perf/core: Run sched_task() for PMUs with only CPU-wide events
perf_pmu_sched_task() returns early when cpuctx->task_ctx is set and
leaves the work to perf_ctx_sched_task_cb(), which only walks
ctx->pmu_ctx_list. A PMU whose events are all CPU-wide is not on that
list, so nothing calls its sched_task(). With

  perf record -b -e cycles -a -- ls

armv8pmu_sched_task() is skipped on every switch to a task that has a
perf context but no event on that PMU, and BRBE records leak across the
task boundary. intel_pmu_lbr_add() calls perf_sched_cb_inc()
unconditionally too, so LBR records leak the same way on x86.

Drop the early return and skip only the CPCs that
perf_ctx_sched_task_cb() handles. That one needs a gate of its own to
make the split exact: it tests cpc->sched_cb_usage, which
perf_sched_cb_inc() sets per CPU for every branch stack user, so a task
with an event for that PMU pinned to another CPU would be handled twice.
On x86 the second __intel_pmu_lbr_restore() finds lbr_stack_state ==
LBR_NONE and calls intel_pmu_lbr_reset(), throwing away the callstack
the first one restored.

cpc->task_epc is set only while a task context is scheduled in, and
there is one epc per PMU on ctx->pmu_ctx_list, so the two gates are
inverses.

For the CPCs perf_pmu_sched_task() picks up, the callback now runs
outside the perf_ctx_disable() and perf_ctx_enable() pair in
perf_event_context_sched_in(). __perf_pmu_sched_task() disables the PMU
around the call itself.

Fixes: bd27568117 ("perf: Rewrite core context handling")
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Yifan Wu <wuyifan50@huawei.com>
Link: https://patch.msgid.link/20260810133540.1947118-3-puranjay@kernel.org
Cc: stable@vger.kernel.org
2026-09-23 11:48:35 +02:00
Puranjay Mohan
36bb85cf36 perf/core: Fix NULL pmu_ctx passed to pmu->sched_task()
perf_pmu_sched_task() returns early when cpuctx->task_ctx is set, and
cpc->task_epc is only non-NULL while a task context is scheduled in on
this CPU. __perf_pmu_sched_task() therefore always passes NULL:

  Unable to handle kernel NULL pointer dereference at virtual address 00
  pc : armv8pmu_sched_task+0x14/0x50
  Call trace:
   armv8pmu_sched_task+0x14/0x50 (P)
   perf_pmu_sched_task+0xac/0x108
   __perf_event_task_sched_out+0x6c/0xe0

Pass &cpc->epc instead, the CPU-wide context for this PMU, which the
function already dereferences a few lines up to find pmu.

armv8pmu_sched_task() is the only in-tree implementation that
dereferences the argument, and it only reads ->pmu, so the oops needs
BRBE, added in v6.17.

Fixes: bd27568117 ("perf: Rewrite core context handling")
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Yifan Wu <wuyifan50@huawei.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260810133540.1947118-2-puranjay@kernel.org
2026-09-23 11:48:35 +02:00
Namhyung Kim
cca4980630 perf/core: Fix a refcount leak in attach_perf_ctx_data()
The attach_perf_ctx_data() can race on global and !global cases.  The
global case is protected by global_ctx_data_rwsem and shares a single
reference count using perf_ctx_data.global field.

But when it races with !global case, it may miss to set the global field
and result in a reference count leak.

 CPU1                                  CPU2
 ----------------------------------------------------------------
 attach_task_ctx_data(.global=1)       attach_task_ctx_data(.global=0)
   cd1 = alloc_perf_ctx_data();          cd2 = alloc_perf_ctx_data();
                                         //    { .global = 0, .refcount = 1 };

                                         try_cmpxchg(); // success,
                                         // task->perf_ctx_data = cd2
   try_cmpxhg(); // fail; old = cd2
   refcount_inc_not_zero(&old->refcount); // success
     // old.refcount = 2
   free_perf_ctx_data(cd1);

Then later detach_global_ctx_data() will see the data but it's not
marked as global, so it won't call detach_task_ctx_data().

Fixes: 506e64e710 ("perf: attach/detach PMU specific data")
Assisted-by: Sashiko.dev:Gemini-3.1-pro
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260920231639.11910-1-namhyung@kernel.org
2026-09-23 11:48:35 +02:00
Weiming Shi
6db1ce73e9
bpf: Reject dev-bound-only programs on other devices
__bpf_offload_dev_match() falls back to comparing offdev pointers after an
exact netdev mismatch. Bound-only programs normally have NULL offdevs, so
unrelated netdevs compare equal. A bound-only program on an
offload-registered netdev can instead inherit a real offdev and match a
sibling port. With CAP_BPF and CAP_NET_ADMIN, a caller can use
bpf(BPF_LINK_CREATE) with a different target ifindex to run metadata kfuncs
specialized for the bound driver on the target driver's xdp_buff. Running a
veth-bound program on tun reads beyond tun's bare stack xdp_buff as a
veth_xdp_buff.

  Oops: general protection fault, probably for non-canonical address
  KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
  RIP: 0010:veth_xdp_rx_timestamp (drivers/net/veth.c:1673)
  Call Trace:
   ...
   tun_build_skb (drivers/net/tun.c:1739)
   tun_get_user (drivers/net/tun.c:1856)
   tun_chr_write_iter (drivers/net/tun.c:2091)
   vfs_write (fs/read_write.c:595 fs/read_write.c:687)
   ksys_write (fs/read_write.c:739)
   do_syscall_64 (arch/x86/entry/syscall_64.c:84)
   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
  Kernel panic - not syncing: Fatal exception in interrupt

Restrict non-offloaded programs to exact netdev matches and retain the
shared-offdev fallback only for genuinely offloaded multi-port programs.

Fixes: 2b3486bc2d ("bpf: Introduce device-bound XDP programs")
Reported-by: <co+ac0a8c41de69121d@bugs.sh>
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260917161335.1020405-2-bestswngs@gmail.com/
Link: https://patch.msgid.link/20260920132303.4109240-3-bestswngs@gmail.com
2026-09-23 02:19:02 +00:00
Emil Tsalapatis
f85f5917aa
bpf: Prevent variable arena/non-arena register contents
The verifier marks ALU instructions that include at least
one arena operand with needs_zext: These instructions are
fixed up after verification to be ALU32 instructions to
ensure that the result is a valid offset into an arena.
However, different code paths may provide two non-arena
64-bit arguments to the same instruction. The result of
the operation in that code path is wrong, since it is
now unexpectedly truncated to 32 bits and zero-extended.

Add logic to the verifier to ensure every instruction either
always has at least one PTR_TO_ARENA argument, or never does.
Since needs_zext already tracks the first scenario, add a
prevent_zext field in bpf_insn_aux to track the latter.
Reject instructions that use arena arguments and have prevent_zext
set, or do not have arena arguments and have needs_zext set.

Fixes: 6082b6c328 ("bpf: Recognize addr_space_cast instruction in the verifier.")
Reported-by: Nicholas Carlini <nicholas@carlini.com>
Suggested-by: Nicholas Carlini <nicholas@carlini.com>
Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20260922172028.6269-8-emil@etsalapatis.com
2026-09-22 19:34:04 +00:00
Emil Tsalapatis
a6c1edfbe2
bpf: Reject pkt arguments in mutating subprogs
The verifier tracks changes in how PTR_TO_PACKET registers'
bounds are modified across subprog boundaries. PTR_TO_PACKET
registers are actually passed as PTR_TO_MEM, which is assumed
valid for the entire call. This is not the case with packet memory,
where a pskb_* call may invalidate its memory region.

Reject BPF code that passes PTR_TO_PACKET pointers to subprogs that
may mutate a packet. We cannot pass the pointer as a true PTR_TO_PACKET
because we would also need to somehow pass the PTR_TO_PACKET_META
or PTR_TO_PACKET_END to the subprog. Since we cannot avoid representing
the pointer in the subprog as PTR_TO_MEM, only permit it if the
subprog is guaranteed not to mutate the packet.

Fixes: 80f281664f5a ("bpf: Support pointers in global func args")
Reported-by: Nicholas Carlini <nicholas@carlini.com>
Suggested-by: Nicholas Carlini <nicholas@carlini.com>
Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20260922172028.6269-6-emil@etsalapatis.com
2026-09-22 19:34:04 +00:00