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53603 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
4cc6bbaeb3 |
srcu: Fix spurious WARN_ON() for rcu_segcblist_n_cbs() in cleanup_srcu_struct()
This issue was introduced during the recent merge window: |
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Linus Torvalds
|
602042bf29 |
workqueue: Fixes for v7.3-rc6
- Fix a NULL dereference in the chained work check when a kworker queues work on a draining or destroying workqueue outside work item execution. -----BEGIN PGP SIGNATURE----- iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCasUtqA4cdGpAa2VybmVs Lm9yZwAKCRCxYfJx3gVYGWk6AP4ih99Tbz+JiBcsIMAB2l6CVmuIzkZ6J1o2V0nh vR5JoQD/UKxcEb/Zu7e+RmdoCa9+nb4E+O+Qt60OncIG5npwxgQ= =TTbp -----END PGP SIGNATURE----- Merge tag 'wq-for-7.3-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull workqueue fixes from Tejun Heo: - Fix a NULL dereference in the chained work check when a kworker queues work on a draining or destroying workqueue outside work item execution. * tag 'wq-for-7.3-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: Fix NULL current_pwq deref in chained work check |
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Linus Torvalds
|
0d32b3ec5f |
cgroup: Fixes for v7.3-rc6
- During CPU offline, the active mask drops the CPU before cpuset updates the effective CPUs, so a task placement in that window could find no active CPU in the top cpuset and dereference NULL. Restore the NULL check. - The cpuset v2-mode test read the subsystem's root pointer, which is stale during a cgroup filesystem rebind, and the hotplug handler evaluated it before taking the cpuset mutex. Record the mode in a flag and test it under the mutex. -----BEGIN PGP SIGNATURE----- iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCasUtqA4cdGpAa2VybmVs Lm9yZwAKCRCxYfJx3gVYGf+HAP9wEWWAp5XQUuDFaWg6Ft8iPw4Tm+b1d2w4c5il j+EGQgD/ce2FLEIu2642xuvQB4XaScJMT7G+3XZplgBsT4/jrA4= =Qa2B -----END PGP SIGNATURE----- Merge tag 'cgroup-for-7.3-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: - During CPU offline, the active mask drops the CPU before cpuset updates the effective CPUs, so a task placement in that window could find no active CPU in the top cpuset and dereference NULL. Restore the NULL check. - The cpuset v2-mode test read the subsystem's root pointer, which is stale during a cgroup filesystem rebind, and the hotplug handler evaluated it before taking the cpuset mutex. Record the mode in a flag and test it under the mutex. * tag 'cgroup-for-7.3-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup/cpuset: Call is_in_v2_mode() after acquiring cpuset_mutex in cpuset_handle_hotplug() cgroup/cpuset: Handle cpu hotplug race in guarantee_active_cpus() cgroup/cpuset: Don't access cpuset_cgrp_subsys.root in is_in_v2_mode() |
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Linus Torvalds
|
762122d75e |
sched_ext: Fixes for v7.3-rc6
- Taking a CPU offline could hang, or stall until the watchdog ejected the BPF scheduler, when tasks on the dying CPU were still held by the scheduler or sitting on a user dispatch queue. Re-enqueue them onto the local queue when the runqueue goes offline so that the CPU pushes them off like the other sched classes. - The sequence number guarding against stale dispatches was per runqueue, so a task re-enqueued on another CPU could get the same number and a dispatch meant for its earlier instance was applied to the new one. Use a per-task counter. - A task dispatched to another CPU's local queue got its ops.dequeue() only when picked to run and flagged as a core-sched pick. Call it at insertion like for same-CPU dispatches. -----BEGIN PGP SIGNATURE----- iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCasUtpQ4cdGpAa2VybmVs Lm9yZwAKCRCxYfJx3gVYGSu5AQDwrICXDyQlGjzAXzFq+bEKVhtMkHxuk8hm5tAy za4AwwD9FjhJHRy5x89TAmea5Cj++AToL6npdEHv7KDcgqNxsAU= =/aDw -----END PGP SIGNATURE----- Merge tag 'sched_ext-for-7.3-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext Pull sched_ext fixes from Tejun Heo: - Taking a CPU offline could hang, or stall until the watchdog ejected the BPF scheduler, when tasks on the dying CPU were still held by the scheduler or sitting on a user dispatch queue. Re-enqueue them onto the local queue when the runqueue goes offline so that the CPU pushes them off like the other sched classes. - The sequence number guarding against stale dispatches was per runqueue, so a task re-enqueued on another CPU could get the same number and a dispatch meant for its earlier instance was applied to the new one. Use a per-task counter. - A task dispatched to another CPU's local queue got its ops.dequeue() only when picked to run and flagged as a core-sched pick. Call it at insertion like for same-CPU dispatches. * tag 'sched_ext-for-7.3-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: Generate qseq from a per-task counter selftests/sched_ext: Add a test for ops.dequeue() on remote local DSQ moves sched_ext: Call ops.dequeue() when a task arrives on a remote local DSQ sched_ext: Fix CPU hotplug hang when a dying CPU's tasks sit in the BPF scheduler |
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Waiman Long
|
b8eb5fd5bd |
cgroup/cpuset: Call is_in_v2_mode() after acquiring cpuset_mutex in cpuset_handle_hotplug()
It is reported by sashiko that calling is_in_v2_mode() outside of
cpuset_mutex critical section in cpuset_handle_hotplug() can introduce
a TOCTOU race where cgroup hierarchy may have changed from v1 to v2 or
vice versa after is_in_v2_mode() is called leading to erroneously skip
the allocation of tmpmasks or incorrectly modify cpus_allowed masks,
resulting in cpuset state corruption. Fix that by calling is_in_v2_mode()
after acquiring the cpuset_mutex.
Fixes:
|
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Linus Torvalds
|
22430ae5d9 |
printk fixes for 7.3-rc7
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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()
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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
|
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Kuba Piecuch
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e6ac89b8b1 |
sched_ext: Generate qseq from a per-task counter
finish_dispatch() uses the qseq embedded in p->scx.ops_state to tell
whether the QUEUED instance of a task it's about to claim is the one
scx_bpf_dsq_insert() saw. qseq is generated from rq->scx.ops_qseq, but
the counters of different rqs are independent, so if a task is dequeued
and re-enqueued on a different rq between scx_bpf_dsq_insert() and
finish_dispatch(), the new QUEUED instance can end up with the same
qseq as the old one:
CPU X CPU Z
----- -----
enqueue p on rq A, qseq = N
ops.dispatch()
scx_bpf_dsq_insert(p)
records qseq N
sched_setaffinity(p)
dequeue p from rq A
enqueue p on rq B, qseq = N
finish_dispatch(p, N)
qseq matches, p is claimed
The claim itself is still atomic so the core stays consistent, but an
insert issued for a previous QUEUED instance gets applied to a new one
which the BPF scheduler has just received through ops.enqueue(). This
breaks the guarantee that dispatches targeting a stale instance are
ignored.
Generate qseq from a per-task counter, p->scx.ops_qseq, instead so that
consecutive QUEUED instances of a task never share a qseq regardless of
which rq they're on. The counter is only updated in
scx_do_enqueue_task() with the task's rq locked, so no additional
synchronization is needed, and it fits in an existing hole in struct
sched_ext_entity on 64bit. Remove the now unused rq->scx.ops_qseq.
Never generate qseq 0. NONE and DISPATCHING don't carry a qseq, so
scx_bpf_dsq_insert() on a task in either state records 0. With a
per-task counter, every task's first QUEUED instance would otherwise get
qseq 0 and could be claimed by such an insert. Wrap the counter where
the QSEQ field wraps so that it can't reach a value that shifts to 0 on
32bit either.
Fixes:
|
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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()
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Linus Torvalds
|
8f150ccedf |
bpf-fixes
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Waiman Long
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23b1ab15ca |
cgroup/cpuset: Handle cpu hotplug race in guarantee_active_cpus()
With commit |
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Ömer Mete Kaya
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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:
|
||
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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:
|
||
|
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:
|
||
|
Petr Mladek
|
c83e3d2912 |
braille: nbcon: Allow to use a serial console with NBCON API as Braille console
The Braille console is not registered in console_list. Instead, it is
integrated with the virtual terminal (VT) and shows what is displayed
on the terminal. It writes the data using con->write*() callback
of the associated serial console driver.
braille_write() is called from the VT code under console_lock().
The associated serial console driver can be converted to the NBCON API
though. The situation is similar to flushing nbcon consoles in the legacy
loop when some boot consoles are still registered, see
nbcon_legacy_emit_next_record().
But there is a big difference though. braille_write() is not directly
called from the code paths flushing registered consoles. The VT code
expects that braille_write() succeeds. It does not replay the message
when it can't acquire the ownership. As a result, braille_write():
+ must try harder to get the ownership.
+ has to be synchronized only against non-printk serial console
which depend nbcon_device_try_acquire() using NBCON_PRIO_NORMAL.
Let's look at it from another side and try to simulate the original
locking using the NBCON API:
1. Take con->device_lock(), aka the port->lock in the legacy serial
console driver.
2. Acquire nbcon context to provide some synchronization for a panic()
context. Use NBCON_PRIO_NORMAL because it contends only with
nbcon_device_try_acquire() users. Do it in a busy loop. It should
always succeed when con->device_lock() succeeded because all other
users do the same. The only exception is when the context get acquired
by a CPU handling panic.
3. In panic, disable interrupts and try to acquire the nbcon context.
Use NBCON_PRIO_PANIC. And try even an unsafe takeover because
otherwise the Braille console won't see the text shown during panic().
It is similar to the oops_in_progress/trylock handling in the legacy
serial console driver.
Finally, avoid the newline prepending logic in the existing serial console
drivers when they are used as a Braille console. As explained above,
the Braille console shows the last modified line on the terminal (VT).
braille_write() is called when single characters are added. Most
messages are not ended by newline. Anyway, the VT code does not have
logic to reply partially printed messages.
Fixes:
|
||
|
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:
|
||
|
Sunho Park
|
26f90559a7 |
srcu: Fix WARN_ON() for rcu_segcblist_n_cbs() in cleanup_srcu_struct()
The WARN_ON() added by commit |
||
|
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:
|
||
|
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> |
||
|
Alexei Starovoitov
|
b88822d258
|
bpf: Fix packet range of pointers sharing an id
Since commit |
||
|
Linus Torvalds
|
703033e235 |
Summary
* Fix sysctl jiffies conversions errors introduced in |
||
|
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:
|
||
|
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:
|
||
|
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:
|
||
|
Linus Torvalds
|
5cd9813d84 |
audit/stable-7.3 PR 20260930
-----BEGIN PGP SIGNATURE----- iQJIBAABCgAyFiEES0KozwfymdVUl37v6iDy2pc3iXMFAmq9uDwUHHBhdWxAcGF1 bC1tb29yZS5jb20ACgkQ6iDy2pc3iXPJLA//fX34uv5DfBWSgIj6BxoeCWYqgRuX nb8kWQQa5lF8u8WhK2z3z8017Pg5aZmQruy+VvLhGf+1L6JmFA8hi9CflGi4RQfB Tii/HQkjxRms+uU4vAManTEyXMGwix6fBTz2S1cfwgfsigBvfrp7xaN9cm7szx19 xd5n7WQHByohz4GFVL0A14S/jmGyLseeLmjB/rbI/gaPRQ+MWL+KfMtM1yigAuf9 RQtJTS7gXw2119m3YGzrMAKqci54acjYWyR7NDB8uGktPI4AKnRA9cNIQWE4c+e6 MCRwHhfjMHKeS54C37CZRvuDh9NAn8DQmhO8SKllfnVlk4T9dYuC0VdbMUTT5IDg r0MFh8hKUibW30pFlJdWembJWsHF94ukDcX2lgwPY/LTnzf3wGaccNKYmuCj3fMR QclScMwg+Hq42PwY8v7aVYICK8B/PHsMULu+GRPSzMXFD7gdxSyFGtMEMSWD/5GV DZdHyGxnOtjVPzc2CEUyMdPWTGUU0QaH6hPSRPmiSuL50TAefh58Rq33fkHZb1X9 15wMvauJPuGeqvyaAqifusof8M0f9uuxGdrbN4T/jnFhzHe58PyogNh/5PychFjC 3fuPW4ByvbXQuLWl80czmxkJ+IVE0p30P4/JRtHwuOcEEKP4+mXhAaMkl0KWd3+d 4s7N0Px8M6pMoNE= =Npw9 -----END PGP SIGNATURE----- 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() |
||
|
Kuba Piecuch
|
af701b8d32 |
sched_ext: Call ops.dequeue() when a task arrives on a remote local DSQ
When a task in the BPF scheduler's custody is moved to another CPU's local DSQ, ops.dequeue() is only called once the task is picked for execution, from set_next_task_scx() with SCX_DEQ_CORE_SCHED_EXEC, even though no core-sched pick took place. It should instead be called without flags when the task is inserted into the destination DSQ, as it is for same-rq dispatches. move_remote_task_to_local_dsq() sets p->scx.sticky_cpu across the migration so that deactivate_task() on the source rq doesn't end custody. Since commit |
||
|
Waiman Long
|
e06b678e3b |
cgroup/cpuset: Don't access cpuset_cgrp_subsys.root in is_in_v2_mode()
After seeing the patch [1] to guard is_in_v2_mode() with RCU, it makes
me realize that is_in_v2_mode() may be called in a context where a new
cgroup filesystem is being rebound with stale cpuset_cgrp_subsys.root
pointer. Avoid this potential UaF situation by adding a new cpuset_v2_mode
flag which is set when the cpuset_v2_mode mount option is used. This
flag is written into only when cpuset_bind() is being called with a
stable cpuset_cgrp_subsys.root value. The is_in_v2_mode() helper is
modified to read the new cpuset_v2_mode flag instead of accessing
cpuset_cgrp_subsys.root directly.
[1] https://lore.kernel.org/lkml/20260929084124.626693-2-arighi@nvidia.com
Fixes:
|
||
|
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:
|
||
|
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
|
||
|
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 |
||
|
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:
|
||
|
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:
|
||
|
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. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCarnNOQAKCRDdBJ7gKXxA jnb1AP9l03wZLtqQJAoTAmRhExD96zqcaFYM/nXgbkXSobw5VwD/dwswYDiV2wjP I6Pn/q0pquurB8RcJhH0Nh4EjmAFDgQ= =1nf9 -----END PGP SIGNATURE----- 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() |
||
|
Pavankumar Kondeti
|
980db94e3e |
workqueue: Fix NULL current_pwq deref in chained work check
current_wq_worker() only tells us that %current is a kworker. It does
not guarantee that the worker is currently executing a work item, as
worker->current_pwq is populated only while process_one_work() is running
the work function.
is_chained_work() can be reached while queueing on a draining or
destroying workqueue. If a kworker outside work-item execution reaches
that path, current_wq_worker() returns a worker but worker->current_pwq is
NULL, and the chained-work test can fault before it emits the intended
warning.
Guard the chained-work test with worker->current_pwq. A kworker without
current_pwq is not executing work on the target workqueue, so the helper
should return false and let the draining/destroying warning fire.
Fixes:
|
||
|
Tejun Heo
|
d35a535d3e |
sched_ext: Fix CPU hotplug hang when a dying CPU's tasks sit in the BPF scheduler
A CPU going down has to empty its own rq. Its hotplug thread waits in sched_cpu_wait_empty() until nothing else is left, and the only thing that wakes it is balance_push(), which runs from __schedule() on the dying CPU and pushes off the migratable tasks the CPU picks. sched_ext breaks this. A task sitting on a user DSQ or held by the BPF scheduler is still counted on its rq, but an inactive CPU no longer calls ops.dispatch() and can't pull the task back. The dying CPU goes idle with the task still counted, and one of two things happens: - Another CPU consumes the task. The rq empties without a __schedule() on the dying CPU, so the hotplug thread is never woken and cpu_down() hangs holding cpu_hotplug_lock. - The task is affine only to the dying CPU. Nothing can move it, and the offline stalls until the watchdog ejects the BPF scheduler. When the rq goes offline, re-enqueue every task on it that isn't already on the local DSQ. An enqueue on an offline rq lands on the local DSQ, so the dying CPU itself picks the tasks and balance_push() pushes them off, the same as for the other sched classes. From then on no sched_ext path on another CPU can pull a task off the rq. ops.dispatch() currently stops as soon as the CPU goes inactive, and CPU hotplug then waits for an RCU grace period before taking the rq offline. A BPF-held task affine only to the dying CPU and preempted inside an RCU read-side critical section would block that grace period, and the rq would never go offline. Test SCX_RQ_ONLINE directly so that ops.dispatch() keeps running until the rq goes offline. Only the dying CPU's own hotplug thread clears the flag during teardown, and task_can_run_on_remote_rq() still keeps other rqs' tasks off the CPU. Fixes: |
||
|
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. -----BEGIN PGP SIGNATURE----- iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCarjXAw4cdGpAa2VybmVs Lm9yZwAKCRCxYfJx3gVYGa2RAQCDvPDErwcBmDHdeAMr6Rr0pXzDf2pYa6LdLL0B XIPCzQD/Y8d3woLh3/CDUfjpkQE/x7QkWj6paZbiILNcenaA+Ac= =wYPe -----END PGP SIGNATURE----- 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 |
||
|
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. -----BEGIN PGP SIGNATURE----- iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCarjXAw4cdGpAa2VybmVs Lm9yZwAKCRCxYfJx3gVYGctVAQD3UPz2537MRkVZtcy4QfgyObMRXEaTGEBBJV+g ougCLgD/ZOVFjyK/bD3wXgtpiRZq9NbL+VvPQfrOjqz3Q/wVww8= =Vyrg -----END PGP SIGNATURE----- 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 |
||
|
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. -----BEGIN PGP SIGNATURE----- iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCarjW+w4cdGpAa2VybmVs Lm9yZwAKCRCxYfJx3gVYGX2cAP0VlU9fUs+6zw+CPEvxDfRClCsMvwpbHEh9EtFQ 1csnhQD+KnIhvmascPtuZLhcYScKfA9ZvvYw/Nme7RVmQ/I8HA8= =UsTG -----END PGP SIGNATURE----- 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 |
||
|
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
|
||
|
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
|
||
|
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:
|
||
|
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:
|
||
|
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:
|
||
|
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 |
||
|
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. -----BEGIN PGP SIGNATURE----- iQFPBAABCgA5FiEEh7BulGwFlgAOi5DV2/sHvwUrPxsFAmq3llUbHG1hc2FtaS5o aXJhbWF0c3VAZ21haWwuY29tAAoJENv7B78FKz8bAhEH/0EAamjv7/EDUoUq+BOO a2gnlYqvr+zcrDVQLNgiYbvTRDfIFPOdB2LpY7Rguee3747qeL7kkNATD10WFr1F 5lXe5LaLncNIrvHDdtcT5eER5ePAuSDMSL5CwnJrRvXJw42iFsqegZ07nrvc9HFS 5zw7Ej9VnFJFxeXIY3J4U92wkntLJ3JhsNheomOtQmEZU1g5ZPAbdq0icNrC3CAb FTezYk60VG0CT/gNTSd8JFnI4P5vKlZpkFFCLLMmptW4yQU9+ZdT55JRgY7wJ8ye w5rLBTRJrFhDgNAjoehMkoAtxik3dKgede7qlwxUk0sv+gwXssw28b5zabRBJgee XQ8= =cHwO -----END PGP SIGNATURE----- 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 |
||
|
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:
|
||
|
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:
|
||
|
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). -----BEGIN PGP SIGNATURE----- iQFGBAABCAAwFiEEcM8Aw/RY0dgsiRUR7l+9nS/U47UFAmq2mDESHHJqd0Byand5 c29ja2kubmV0AAoJEO5fvZ0v1OO1wFAH/2e9iz++Qjb9SODpGX/2Fz07qb4SBRCP Zf0r74G7qfoPczcLuiKu8irb1FSvlwr1nlcygWcF0gYLg9TJCaaQ7JIxHL/9ePV0 lbINk+4ozu5S6AbMh7O5wpv3n+nwBtg1wZZP3kSY4hxQ5zymACuEzwBTGT9vfQVA GpkrasgQVTOyt1gWAO8Ak3WX3z1EaBqzl8DsCm/75PVq2Wy1I801JagtYT6KArf6 kqH19SdiihrTl+2k/k2Vvc14H9XYfXab77ShWv1JgKF7X1QqaO8QWVFQulj0bpgc LLSlpiQXqBYfz469bPGyS2U6tyFioynqoiWQfdxC6zBGcHv1Jl3LdDg= =mfRN -----END PGP SIGNATURE----- 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 |
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Andrea Parri
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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:
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