Pull timer fix from Ingo Molnar: "Fix an argument order bug in the alarm timer forwarding logic, which may cause missed expirations or incorrect overrun accounting" * tag 'timers-urgent-2026-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: alarmtimer: Fix argument order in alarm_timer_forward()
Pull futex fixes from Ingo Molnar: - Tighten up the sys_futex_requeue() ABI a bit, to disallow dissimilar futex flags and potential UaF access (Peter Zijlstra) - Fix UaF between futex_key_to_node_opt() and vma_replace_policy() (Hao-Yu Yang) - Clear stale exiting pointer in futex_lock_pi() retry path, which triggered a warning (and potential misbehavior) in stress-testing (Davidlohr Bueso) * tag 'locking-urgent-2026-03-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Clear stale exiting pointer in futex_lock_pi() retry path futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy() futex: Require sys_futex_requeue() to have identical flags
Pull tracing fixes from Steven Rostedt: - Fix potential deadlock in osnoise and hotplug The interface_lock can be called by a osnoise thread and the CPU shutdown logic of osnoise can wait for this thread to finish. But cpus_read_lock() can also be taken while holding the interface_lock. This produces a circular lock dependency and can cause a deadlock. Swap the ordering of cpus_read_lock() and the interface_lock to have interface_lock taken within the cpus_read_lock() context to prevent this circular dependency. - Fix freeing of event triggers in early boot up If the same trigger is added on the kernel command line, the second one will fail to be applied and the trigger created will be freed. This calls into the deferred logic and creates a kernel thread to do the freeing. But the command line logic is called before kernel threads can be created and this leads to a NULL pointer dereference. Delay freeing event triggers until late init. * tag 'trace-v7.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Drain deferred trigger frees if kthread creation fails tracing: Fix potential deadlock in cpu hotplug with osnoise
Fuzzying/stressing futexes triggered:
WARNING: kernel/futex/core.c:825 at wait_for_owner_exiting+0x7a/0x80, CPU#11: futex_lock_pi_s/524
When futex_lock_pi_atomic() sees the owner is exiting, it returns -EBUSY
and stores a refcounted task pointer in 'exiting'.
After wait_for_owner_exiting() consumes that reference, the local pointer
is never reset to nil. Upon a retry, if futex_lock_pi_atomic() returns a
different error, the bogus pointer is passed to wait_for_owner_exiting().
CPU0 CPU1 CPU2
futex_lock_pi(uaddr)
// acquires the PI futex
exit()
futex_cleanup_begin()
futex_state = EXITING;
futex_lock_pi(uaddr)
futex_lock_pi_atomic()
attach_to_pi_owner()
// observes EXITING
*exiting = owner; // takes ref
return -EBUSY
wait_for_owner_exiting(-EBUSY, owner)
put_task_struct(); // drops ref
// exiting still points to owner
goto retry;
futex_lock_pi_atomic()
lock_pi_update_atomic()
cmpxchg(uaddr)
*uaddr ^= WAITERS // whatever
// value changed
return -EAGAIN;
wait_for_owner_exiting(-EAGAIN, exiting) // stale
WARN_ON_ONCE(exiting)
Fix this by resetting upon retry, essentially aligning it with requeue_pi.
Fixes: 3ef240eaff36 ("futex: Prevent exit livelock")
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260326001759.4129680-1-dave@stgolabs.net
Boot-time trigger registration can fail before the trigger-data cleanup
kthread exists. Deferring those frees until late init is fine, but the
post-boot fallback must still drain the deferred list if kthread
creation never succeeds.
Otherwise, boot-deferred nodes can accumulate on
trigger_data_free_list, later frees fall back to synchronously freeing
only the current object, and the older queued entries are leaked
forever.
To trigger this, add the following to the kernel command line:
trace_event=sched_switch trace_trigger=sched_switch.traceon,sched_switch.traceon
The second traceon trigger will fail and be freed. This triggers a NULL
pointer dereference and crashes the kernel.
Keep the deferred boot-time behavior, but when kthread creation fails,
drain the whole queued list synchronously. Do the same in the late-init
drain path so queued entries are not stranded there either.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260324221326.1395799-3-atwellwea@gmail.com
Fixes: 61d445af0a7c ("tracing: Add bulk garbage collection of freeing event_trigger_data")
Signed-off-by: Wesley Atwell <atwellwea@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Pull sysctl fix from Joel Granados: "Fix uninitialized variable error when writing to a sysctl bitmap Removed the possibility of returning an unjustified -EINVAL when writing to a sysctl bitmap" * tag 'sysctl-7.00-fixes-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl: sysctl: fix uninitialized variable in proc_do_large_bitmap
The following sequence may leads deadlock in cpu hotplug:
task1 task2 task3
----- ----- -----
mutex_lock(&interface_lock)
[CPU GOING OFFLINE]
cpus_write_lock();
osnoise_cpu_die();
kthread_stop(task3);
wait_for_completion();
osnoise_sleep();
mutex_lock(&interface_lock);
cpus_read_lock();
[DEAD LOCK]
Fix by swap the order of cpus_read_lock() and mutex_lock(&interface_lock).
Cc: stable@vger.kernel.org
Cc: <mathieu.desnoyers@efficios.com>
Cc: <zhang.run@zte.com.cn>
Cc: <yang.tao172@zte.com.cn>
Cc: <ran.xiaokai@zte.com.cn>
Fixes: bce29ac9ce0bb ("trace: Add osnoise tracer")
Link: https://patch.msgid.link/20260326141953414bVSj33dAYktqp9Oiyizq8@zte.com.cn
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Luo Haiyang <luo.haiyang@zte.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Pull power management fixes from Rafael Wysocki:
"These fix two cpufreq issues, one in the core and one in the
conservative governor, and two issues related to system sleep:
- Restore the cpufreq core behavior changed inadvertently during the
6.19 development cycle to call cpufreq_frequency_table_cpuinfo()
for cpufreq policies getting re-initialized which ensures that
policy->max and policy->cpuinfo_max_freq will be valid going
forward (Viresh Kumar)
- Adjust the cached requested frequency in the conservative cpufreq
governor on policy limits changes to prevent it from becoming stale
in some cases (Viresh Kumar)
- Prevent pm_restore_gfp_mask() from triggering a WARN_ON() in some
code paths in which it is legitimately called without invoking
pm_restrict_gfp_mask() previously (Youngjun Park)
- Update snapshot_write_finalize() to take trailing zero pages into
account properly which prevents user space restore from failing
subsequently in some cases (Alberto Garcia)"
* tag 'pm-7.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM: sleep: Drop spurious WARN_ON() from pm_restore_gfp_mask()
PM: hibernate: Drain trailing zero pages on userspace restore
cpufreq: conservative: Reset requested_freq on limits change
cpufreq: Don't skip cpufreq_frequency_table_cpuinfo()
Pull dma-mapping fixes from Marek Szyprowski: "A set of fixes for DMA-mapping subsystem, which resolve false- positive warnings from KMSAN and DMA-API debug (Shigeru Yoshida and Leon Romanovsky) as well as a simple build fix (Miguel Ojeda)" * tag 'dma-mapping-7.0-2026-03-25' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux: dma-mapping: add missing `inline` for `dma_free_attrs` mm/hmm: Indicate that HMM requires DMA coherency RDMA/umem: Tell DMA mapping that UMEM requires coherency iommu/dma: add support for DMA_ATTR_REQUIRE_COHERENT attribute dma-direct: prevent SWIOTLB path when DMA_ATTR_REQUIRE_COHERENT is set dma-mapping: Introduce DMA require coherency attribute dma-mapping: Clarify valid conditions for CPU cache line overlap dma-mapping: handle DMA_ATTR_CPU_CACHE_CLEAN in trace output dma-debug: Allow multiple invocations of overlapping entries dma: swiotlb: add KMSAN annotations to swiotlb_bounce()
During futex_key_to_node_opt() execution, vma->vm_policy is read under
speculative mmap lock and RCU. Concurrently, mbind() may call
vma_replace_policy() which frees the old mempolicy immediately via
kmem_cache_free().
This creates a race where __futex_key_to_node() dereferences a freed
mempolicy pointer, causing a use-after-free read of mpol->mode.
[ 151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349)
[ 151.414046] Read of size 2 at addr ffff888001c49634 by task e/87
[ 151.415969] Call Trace:
[ 151.416732] __asan_load2 (mm/kasan/generic.c:271)
[ 151.416777] __futex_key_to_node (kernel/futex/core.c:349)
[ 151.416822] get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593)
Fix by adding rcu to __mpol_put().
Fixes: c042c505210d ("futex: Implement FUTEX2_MPOL")
Reported-by: Hao-Yu Yang <naup96721@gmail.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Hao-Yu Yang <naup96721@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Link: https://patch.msgid.link/20260324174418.GB1850007@noisy.programming.kicks-ass.net