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8f150ccedf
53579 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
8f150ccedf |
bpf-fixes
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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:
|
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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:
|
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Alexei Starovoitov
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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> |
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Alexei Starovoitov
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b88822d258
|
bpf: Fix packet range of pointers sharing an id
Since commit |
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Linus Torvalds
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703033e235 |
Summary
* Fix sysctl jiffies conversions errors introduced in |
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Linus Torvalds
|
5cd9813d84 |
audit/stable-7.3 PR 20260930
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Zhan Xusheng
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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
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Zhan Xusheng
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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 |
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Florent Revest (Anthropic)
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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:
|
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Florent Revest (Anthropic)
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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:
|
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Linus Torvalds
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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() |
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Linus Torvalds
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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 |
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Linus Torvalds
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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 |
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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 |
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Linus Torvalds
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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
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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 |
||
|
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:
|
||
|
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:
|
||
|
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. -----BEGIN PGP SIGNATURE----- iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCarWSLQ4cdGpAa2VybmVs Lm9yZwAKCRCxYfJx3gVYGY+sAP9y6nJh6vIvFh/X9FlJtWlNo0mncOKhy93E8jii 8CKnPQEAhvX3+Gcdl+imTh4Z915kdsEByBjTTPPOXnQxI8BKUAY= =VhBF -----END PGP SIGNATURE----- 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 |
||
|
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. -----BEGIN PGP SIGNATURE----- iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCarWSKg4cdGpAa2VybmVs Lm9yZwAKCRCxYfJx3gVYGYoiAQD6JUCqDjv2Hr1YeMFlsoYVQZ7tNmljVnPD2tZ6 9WmD/AEAotdlmzM8egOuDqAi2s+UMJPm8vCZuxVzewiGqhYELgk= =0Ljp -----END PGP SIGNATURE----- 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 |
||
|
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:
|
||
|
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
...
|
||
|
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:
|
||
|
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 |
||
|
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:
|
||
|
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:
|
||
|
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:
|
||
|
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:
|
||
|
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:
|
||
|
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:
|
||
|
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
|
||
|
Florian Schmaus
|
41112a787f |
PM: hibernate: Freeze kernel threads after image preallocation
Commit |
||
|
Davi Chaves Azevedo
|
3cb0243767 |
sched/cache: Refresh LLC capacity across CPU hotplug, to fix capacity underestimation bug
The scheduler scales LLC capacity by the fraction of cache-sharing CPUs
covered by a domain:
llc_bytes = cache_size * span_weight / shared_weight
During CPU teardown, sched_cpu_deactivate() rebuilds scheduler domains
before cacheinfo_cpu_pre_down() removes the CPU from shared_cpu_map. The
new domains therefore use the old sharing weight. The later call to
sched_update_llc_bytes() looks up the departing CPU's sd_llc, which has
already been detached, and returns without correcting the surviving CPUs.
On a Ryzen 5 7535U with twelve logical CPUs sharing a 16 MiB LLC,
offlining one SMT sibling left the remaining CPUs with:
llc_bytes = floor(16777216 * 11 / 12) = 15379114 bytes
The correct capacity is still 16777216 bytes. On systems with active
cache-aware scheduling, an underestimated capacity can cause
exceed_llc_capacity() to reject aggregation for a process whose footprint
would fit. Unchanged cpuset partitions sharing the physical cache can
also retain stale capacity when a CPU comes online in another partition.
Pass the cache-sharing mask already retained by cacheinfo to the
scheduler update. Refresh every surviving CPU using its own LLC domain
so that each partition receives the correct share. This also preserves
the correction needed as cache-sharing maps grow during boot.
Keep the existing CPU-hotplug and scheduler-domain synchronization. The
update remains on the hotplug path; no steady-state scheduling operation
or persistent allocation is added.
Fixes:
|
||
|
Chen Yu
|
65efcccddc |
sched/cache: Skip kernel threads for cache aware scheduling to rubustify the code
Kernel thread should not be covered by cache aware scheduling as
it borrows the statistics from the user space thread. Filter the
kernel thread in account_mm_sched().
In theory a kernel thread does not have any valid
cache group, so !grp should gate the kernel thread.
Add the PF_KTHREAD check explicitly here for safety
reasons, to guard against future modifications and
to pair with task_tick_cache().
Fixes:
|
||
|
Tim Chen
|
b636fef85b |
sched/cache: Introduce task_struct->sched_cache_grp to fix UAF
Add a sched_cache_grp pointer to task_struct so that scheduler code
can access the cache group directly via the task, without going
through mm->sched_cache_grp. This decouples the scheduler's hot-path
accesses from the mm_struct.
Each task holds its own refcount on the sched_cache_group, separate
from the reference held by its mm_struct. The reference is acquired
in copy_mm() (fork) and exec_mmap() (exec), and released in exit_mm().
This fixes the use-after-free when account_mm_sched() reaches the group
through a task whose mm is being switched, as reported by Hyunwoo:
https://lore.kernel.org/lkml/apPb-Dr4nPYuHQOK@v4bel/
Convert all scheduler code in fair.c and exit.c to use
p->sched_cache_grp instead of p->mm->sched_cache_grp.
Keep the fork/exec/exit reference management out of the generic mm
paths: add sched_cache_fork(), sched_cache_fork_cleanup(),
sched_cache_exec_mmap() and sched_cache_exit_mm() in
kernel/sched/cache_sched.c (with empty stubs for !CONFIG_SCHED_CACHE),
so fs/exec.c, kernel/fork.c and kernel/exit.c each call one helper
instead of open-coding the refcounting under #ifdef. Also add
sched_cache_group_get() and task_cache_group_get().
Fixes:
|
||
|
Tim Chen
|
28f9c0e0a0 |
sched/cache: Decouple sched_cache_group from mm to fix UAF
Currently the sched cache grouping is by mm and the scheduling statistics
sched_cache_stat lives in the mm structure. This ties the life cycle
of scheduling stats with mm.
In account_mm_sched(), the scheduling stats are accessed by
task->mm->sc_stat. However, a task may be switching mm on one CPU when
another CPU is running account_mm_sched(), and possibly accessing the
old mm that was freed. This problem was found when running tests with
KASAN by Hyunwoo:
https://lore.kernel.org/lkml/apPb-Dr4nPYuHQOK@v4bel/
Instead of serializing the mm access by introducing extra acquisition of
rq lock in the mm free path, extract sched_cache_stat from mm_struct,
rename it as sched_cache_group and manage its life cycle apart from
mm_struct with its own ref counting. This allows us in the next patch
access sched_cache_group directly from task, and add a refcount
on sched_cache_group when a task links to it. This prevents the use
after free issue when accessing stale and released old mm and its
sched cache stat a task switches to a new mm while account_mm_sched()
is done elsewhere.
The other benefit of this restructure is in the future, the grouping of
tasks to a LLC would have the flexibility to be associated with a user
defined grouping, or cgroup, cookie group, numa_group or others instead
of just with a single mm address space.
Rename sched_cache_stat to sched_cache_group and turn it into a refcounted
object allocated from mm_struct. The mm_struct now holds a pointer
(sched_cache_grp) to this object instead of embedding it.
Fixes:
|
||
|
Lu Wang
|
d6013e2465 |
sched/cache: Honor migrate_llc_task semantics in active load balance, to fix LLC mis-scheduling bug
Cache aware scheduling introduced the migrate_llc_task migration type to direct
tasks toward their preferred LLC, but its semantics can be lost when passive
load balance falls back to active load balance (ALB). This may allow ALB to
select a candidate whose preferred LLC does not match the destination, moving
it away from its preferred LLC.
Example scenario:
src_rq has two runnable tasks, p1 and p2. p1 prefers dst_rq (dst_llc), while p2
prefers src_rq (src_llc). In this case, migrate_llc_task is set because src_rq
has at least one task, p1, that wants to migrate to dst_rq. In ALB,
can_migrate_task() finds p2 and returns true for it, thus moving p2 out of its
preferred LLC.
Solution:
The CPU stopper in ALB constructs a fresh lb_env that does not inherit
migration_type from the passive load-balance pass. Two approaches are
possible:
(a) Add a new member to struct rq so ALB can inherit migrate_llc_task
from the passive LB that triggered it.
(b) Define a new flag LBF_ACTIVE_LB_LLC and select the stopper callback
at kick time to preserve the migration semantics across the
asynchronous boundary.
We choose (b) because it avoids passing migration_type through the
stopper, which would affect the meaning of migration_type for
delayed-dequeue tasks.
Fixes:
|
||
|
Tim Chen
|
0d6526f82c |
sched/cache: Keep nr_pref_llc_running in the runnable domain, to fix LLC mis-scheduling bug
alb_break_llc() decides whether to break LLC preference during active
load balance. It does so by testing that every runnable fair task on the
source rq prefers its LLC:
env->src_rq->nr_pref_llc_running == env->src_rq->cfs.h_nr_runnable
But the two counters cover different sets. nr_pref_llc_running is updated
in account_llc_enqueue()/account_llc_dequeue(), next to cfs_rq->nr_queued,
so it follows queued tasks. h_nr_runnable is updated in set_delayed()/
clear_delayed() and drops delay-dequeued tasks.
So under DELAY_DEQUEUE, a preferring task that goes to sleep stays counted
in nr_pref_llc_running while h_nr_runnable falls. The equality then breaks,
alb_break_llc() returns false, and active balance is free to pull a task
off its preferred LLC. Active balance only moves runnable tasks, and this
is the only LLC check it consults: once the stopper runs, LBF_ACTIVE_LB
skips the per-task test in can_migrate_task(). The runnable set is the one
we want.
Fix it on the counter side. A task should be counted in
nr_pref_llc_running exactly while it is both queued on its preferred LLC
(pref_llc_queued) and runnable (!sched_delayed). Define that membership
once in task_pref_llc_runnable(), and adjust the counter only through
pref_llc_running_inc()/pref_llc_running_dec() from the four sites that
change either input: account_llc_enqueue(), account_llc_dequeue(),
set_delayed() and clear_delayed(). Gating every update on the same
predicate keeps the delay, wake and dequeue paths from double-counting
or underflowing; see the comments at those sites for the ordering.
nr_llc_running and sd->llc_counts are not touched and stay on queued
semantics.
Fixes:
|
||
|
Xu Yunxiang
|
79a9172f3a |
bpf: Reject non-negative offsets in stack_slot_obj_get_spi()
bpf_get_spi() computes (-off - 1) / BPF_REG_SIZE using C division,
which truncates toward zero. For off == 0, this produces spi 0, the
same index used by the valid stack slot at fp-8.
stack_slot_obj_get_spi() currently checks alignment and the resulting
spi bounds, but does not reject the non-negative offset itself. It can
therefore validate a PTR_TO_STACK register holding fp+0 against an
iterator stored at fp-8 even though the runtime receives the actual fp+0
pointer. An effectful iterator kfunc can then interpret memory outside
the BPF stack as iterator state.
Reject non-negative offsets before converting the offset to an spi. All
valid stack objects begin at a negative offset from the frame pointer.
Fixes:
|
||
|
Linus Torvalds
|
0a15ba6b0c |
Timer race fixes:
- Fix timer signal <-> exec() race, to prevent UAF (Thomas Gleixner)
- Clean up POSIX CPU timers right after de_thread(), to prevent UAF
(Hyunwoo Kim)
- Fix POSIX CPU timers race between expiry and timer_settime(),
to prevent UAF (Thomas Gleixner)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'timers-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer race fixes from Ingo Molnar:
- Fix timer signal <-> exec() race, to prevent UAF (Thomas Gleixner)
- Clean up POSIX CPU timers right after de_thread(), to prevent UAF
(Hyunwoo Kim)
- Fix POSIX CPU timers race between expiry and timer_settime(),
to prevent UAF (Thomas Gleixner)
* tag 'timers-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-cpu-timers: Prevent freeing a timer which is queued on the expiry list
exec: Cleanup POSIX timers right after de_thread()
signal: Prevent exec() race
|
||
|
Linus Torvalds
|
fecbe78ac0 |
Scheduler fix:
- Avoid false positive migration warning for proxy donors
(Andrea Righi)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Ingo Molnar:
- Avoid false positive migration warning for proxy donors
(Andrea Righi)
* tag 'sched-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/core: Avoid false migration warning for proxy donors
|