<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/kernel/exit.c, branch v7.3-rc2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge tag 'locking-urgent-2026-08-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2026-08-22T23:29:20+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-08-22T23:29:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0d78592583949b531318b51763ade7ff536ba9bc'/>
<id>0d78592583949b531318b51763ade7ff536ba9bc</id>
<content type='text'>
Pull futex fixes from Ingo Molnar:

 - Enforce that the private futex owner shares the mm when attaching
   (Kyle Zeng, Thomas Gleixner)

 - Fix race on the initial mm-&gt;futex.phash.ref allocation (Hyunwoo Kim)

 - Fix might_sleep() warning in futex_pivot_pending() (Peter Zijlstra)

* tag 'locking-urgent-2026-08-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Fix might_sleep() warning in futex_pivot_pending()
  futex: Fix race on the initial mm-&gt;futex.phash.ref allocation
  futex: Clean up the redundant exit/exec functions
  futex/pi: Plug private futex exec() race
  futex: Sanitize and document task_struct::futex::state transitions
  futex/pi: Reject cross-mm private futex owners
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull futex fixes from Ingo Molnar:

 - Enforce that the private futex owner shares the mm when attaching
   (Kyle Zeng, Thomas Gleixner)

 - Fix race on the initial mm-&gt;futex.phash.ref allocation (Hyunwoo Kim)

 - Fix might_sleep() warning in futex_pivot_pending() (Peter Zijlstra)

* tag 'locking-urgent-2026-08-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Fix might_sleep() warning in futex_pivot_pending()
  futex: Fix race on the initial mm-&gt;futex.phash.ref allocation
  futex: Clean up the redundant exit/exec functions
  futex/pi: Plug private futex exec() race
  futex: Sanitize and document task_struct::futex::state transitions
  futex/pi: Reject cross-mm private futex owners
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-7.3/block-20260819' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux</title>
<updated>2026-08-20T20:55:16+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-08-20T20:55:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=55ab7e14222e5f0b0fd9f7711ca391d2924b35e3'/>
<id>55ab7e14222e5f0b0fd9f7711ca391d2924b35e3</id>
<content type='text'>
Pull block updates from Jens Axboe:

 - NVMe updates via Keith:
     - Enable Clang context analysis for the nvme host driver, adding
       context annotations across core, fabrics, rdma, tcp and pci
     - nvmet reservation state exposed through a new namespace-level
       debugfs directory, plus ABI documentation for the host sysfs and
       target configfs interfaces
     - nvme-tcp host memory disclosure fixes on the read path: reject a
       read that transferred too few bytes, don't accept C2HData based
       on blk_rq_payload_bytes() alone, and fix the R2T case for a read
       command
     - Parallelize nvme-rdma I/O queue allocation and startup (Surabhi)
     - Apple nvme fixes and quirks: page aligned admin queue buffers,
       destroy the admin queue on removal, and various DMA/NVMMU
       correctness fixes
     - A large pile of nvmet and host fixes for out-of-bounds reads,
       refcount/resource leaks, and NULL derefs across auth, zns,
       passthru, pci-epf, rdma and configfs
     - Various other fixes and cleanups

 - MD updates via Yu Kuai:
     - llbitmap reshape support, the large series wiring exact bitmap
       mapping and reshape lifecycle through raid5 and raid10, growing
       the page cache in place, and remapping checkpointed bits as
       reshape progresses
     - raid5 fixes for lockless max_nr_stripes and recovery_offset
       accesses, a reshape deadlock with more failed devices than max
       degraded, and bitmap batch counter consistency
     - Atomic write handling for raid1/raid10, and removal of the
       REQ_NOWAIT support from raid1/10/456
     - raid5-ppl use-after-free fix in ppl_do_flush()
     - A batch of smaller fixes across md core and the bitmap code

 - s390/dasd ESE full-track write support and the surrounding
   infrastructure, plus enabling CONTEXT_ANALYSIS for s390/block

 - RWF_DONTCACHE support for block devices, built on new task-context
   bio completion infrastructure, and wiring it up for the iomap and
   buffer dropbehind writeback paths

 - Async io_uring zone reset all, plus zone management command cleanups
   allowing REQ_NOWAIT and tightening conventional zone rejection

 - Block integrity refactoring: lift BIP_CHECK_FLAGS to the shared
   header, handle nogenerate/noverify properly in fs-integrity, and drop
   the blk-integrity.h include from bdev.c

 - Split out a new blk_plug.h header

 - ublk improvements: add UBLK_F_IO_DESC_SIZE, split request validation
   from io_desc init, reject non-power-of-2 zone sizes in SET_PARAMS,
   and a series of hardening fixes around map/unmap and auto buf reg

 - null_blk cleanups and configfs serialization fixes

 - nbd queue freeze removal on the setup paths, and a new
   pre_defined_connections module parameter for pre-created devices

 - blk-cgroup fixes for the race between policy activation and blkg
   destruction, and accounting per-cpu stats over possible CPUs across
   blk-stat, iolatency, iocost and kyber

 - Various dio fixes: leak on metadata mapping error, validate user
   space vectors during extraction, and set dma_alignment from the
   backing file for loop and zloop direct I/O

 - bio cleanups

 - Various other fixes and cleanups all over

* tag 'for-7.3/block-20260819' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (241 commits)
  nbd: add pre_defined_connections module parameter for pre-created devices
  nbd: remove queue freeze for newly created nbd from netlink path
  nbd: factor out a nbd_genl_foreach_sock
  nbd: skip queue freeze when setting size at device startup
  nbd: remove queue freeze in nbd_add_socket
  nbd: clear queue limits on disconnect
  nbd: disallow NBD_SET_SOCK on an active device
  nbd: simplify find_fallback() by removing redundant logic
  blk-mq: add missing call to srcu_barrier() in blk_mq_free_tag_set()
  block: mtip32xx: synchronize ioctls with device removal
  ublk: avoid teardown retry loop on xarray allocation failure
  null_blk: fix UBSAN shift-out-of-bounds when zone_size is 0 or overflows
  block: don't include blk-integrity.h in bdev.c
  xfs: avoid double deferrals for RWF_DONTCACHE writes
  loop: Fix recently introduced lock inversion
  block: set QUEUE_FLAG_DYING unconditionally in blk_mark_disk_dead()
  swim3: Add missing MODULE_DESCRIPTION
  selftests: ublk: add SET_PARAMS validation test
  selftests: ublk: add helper for SET_PARAMS
  ublk: reject non-power-of-2 zone sizes in SET_PARAMS
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull block updates from Jens Axboe:

 - NVMe updates via Keith:
     - Enable Clang context analysis for the nvme host driver, adding
       context annotations across core, fabrics, rdma, tcp and pci
     - nvmet reservation state exposed through a new namespace-level
       debugfs directory, plus ABI documentation for the host sysfs and
       target configfs interfaces
     - nvme-tcp host memory disclosure fixes on the read path: reject a
       read that transferred too few bytes, don't accept C2HData based
       on blk_rq_payload_bytes() alone, and fix the R2T case for a read
       command
     - Parallelize nvme-rdma I/O queue allocation and startup (Surabhi)
     - Apple nvme fixes and quirks: page aligned admin queue buffers,
       destroy the admin queue on removal, and various DMA/NVMMU
       correctness fixes
     - A large pile of nvmet and host fixes for out-of-bounds reads,
       refcount/resource leaks, and NULL derefs across auth, zns,
       passthru, pci-epf, rdma and configfs
     - Various other fixes and cleanups

 - MD updates via Yu Kuai:
     - llbitmap reshape support, the large series wiring exact bitmap
       mapping and reshape lifecycle through raid5 and raid10, growing
       the page cache in place, and remapping checkpointed bits as
       reshape progresses
     - raid5 fixes for lockless max_nr_stripes and recovery_offset
       accesses, a reshape deadlock with more failed devices than max
       degraded, and bitmap batch counter consistency
     - Atomic write handling for raid1/raid10, and removal of the
       REQ_NOWAIT support from raid1/10/456
     - raid5-ppl use-after-free fix in ppl_do_flush()
     - A batch of smaller fixes across md core and the bitmap code

 - s390/dasd ESE full-track write support and the surrounding
   infrastructure, plus enabling CONTEXT_ANALYSIS for s390/block

 - RWF_DONTCACHE support for block devices, built on new task-context
   bio completion infrastructure, and wiring it up for the iomap and
   buffer dropbehind writeback paths

 - Async io_uring zone reset all, plus zone management command cleanups
   allowing REQ_NOWAIT and tightening conventional zone rejection

 - Block integrity refactoring: lift BIP_CHECK_FLAGS to the shared
   header, handle nogenerate/noverify properly in fs-integrity, and drop
   the blk-integrity.h include from bdev.c

 - Split out a new blk_plug.h header

 - ublk improvements: add UBLK_F_IO_DESC_SIZE, split request validation
   from io_desc init, reject non-power-of-2 zone sizes in SET_PARAMS,
   and a series of hardening fixes around map/unmap and auto buf reg

 - null_blk cleanups and configfs serialization fixes

 - nbd queue freeze removal on the setup paths, and a new
   pre_defined_connections module parameter for pre-created devices

 - blk-cgroup fixes for the race between policy activation and blkg
   destruction, and accounting per-cpu stats over possible CPUs across
   blk-stat, iolatency, iocost and kyber

 - Various dio fixes: leak on metadata mapping error, validate user
   space vectors during extraction, and set dma_alignment from the
   backing file for loop and zloop direct I/O

 - bio cleanups

 - Various other fixes and cleanups all over

* tag 'for-7.3/block-20260819' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (241 commits)
  nbd: add pre_defined_connections module parameter for pre-created devices
  nbd: remove queue freeze for newly created nbd from netlink path
  nbd: factor out a nbd_genl_foreach_sock
  nbd: skip queue freeze when setting size at device startup
  nbd: remove queue freeze in nbd_add_socket
  nbd: clear queue limits on disconnect
  nbd: disallow NBD_SET_SOCK on an active device
  nbd: simplify find_fallback() by removing redundant logic
  blk-mq: add missing call to srcu_barrier() in blk_mq_free_tag_set()
  block: mtip32xx: synchronize ioctls with device removal
  ublk: avoid teardown retry loop on xarray allocation failure
  null_blk: fix UBSAN shift-out-of-bounds when zone_size is 0 or overflows
  block: don't include blk-integrity.h in bdev.c
  xfs: avoid double deferrals for RWF_DONTCACHE writes
  loop: Fix recently introduced lock inversion
  block: set QUEUE_FLAG_DYING unconditionally in blk_mark_disk_dead()
  swim3: Add missing MODULE_DESCRIPTION
  selftests: ublk: add SET_PARAMS validation test
  selftests: ublk: add helper for SET_PARAMS
  ublk: reject non-power-of-2 zone sizes in SET_PARAMS
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tags 'ipc-7.3-rc1.misc' and 'kernel-7.3-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs</title>
<updated>2026-08-17T15:27:30+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-08-17T15:27:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=043d7a2b4045df5eebc699c39bc3a571afb9f1ae'/>
<id>043d7a2b4045df5eebc699c39bc3a571afb9f1ae</id>
<content type='text'>
Pull misc ipc and core updates from Christian Brauner:

 - reject mq_notify() with a zero signal number

 - fix coding style in the exit path

* tag 'ipc-7.3-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  mqueue: reject mq_notify with signo 0

* tag 'kernel-7.3-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  kernel: exit: fix coding style missing spaces
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull misc ipc and core updates from Christian Brauner:

 - reject mq_notify() with a zero signal number

 - fix coding style in the exit path

* tag 'ipc-7.3-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  mqueue: reject mq_notify with signo 0

* tag 'kernel-7.3-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  kernel: exit: fix coding style missing spaces
</pre>
</div>
</content>
</entry>
<entry>
<title>futex: Clean up the redundant exit/exec functions</title>
<updated>2026-08-15T22:16:32+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@kernel.org</email>
</author>
<published>2026-08-07T15:07:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=221b62e97811845340c888993ae049467399d2b5'/>
<id>221b62e97811845340c888993ae049467399d2b5</id>
<content type='text'>
futex_exit_release() and futex_exec_release() are identical now. That means
also exit_mm_release() and exec_mm_release() are identical.

Consolidate the whole lot and remove the redundant copies.

Signed-off-by: Thomas Gleixner &lt;tglx@kernel.org&gt;
Reviewed-by: Kyle Zeng &lt;kylebot@openai.com&gt;
Acked-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
futex_exit_release() and futex_exec_release() are identical now. That means
also exit_mm_release() and exec_mm_release() are identical.

Consolidate the whole lot and remove the redundant copies.

Signed-off-by: Thomas Gleixner &lt;tglx@kernel.org&gt;
Reviewed-by: Kyle Zeng &lt;kylebot@openai.com&gt;
Acked-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: split out a new blk_plug.h header</title>
<updated>2026-08-04T12:57:05+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2026-08-04T12:55:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=758b86f7bc8a2582d0783f3535854ea05d3ff97d'/>
<id>758b86f7bc8a2582d0783f3535854ea05d3ff97d</id>
<content type='text'>
blkdev.h gets included in various places outside the block layer just
for struct blk_plug and related plugging functions.

Split blk_plug into a separate helper to reduce the amount of code
that needs to get rebuilt when blkdev.h changes and to slightly
reduce compile times.

In io_uring this requires pulling in a few other headers explicitly that
previously were implicitly included through blkdev.h.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Christian Brauner (Amutable) &lt;brauner@kernel.org&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Reviewed-by: Damien Le Moal &lt;dlemoal@kernel.org&gt;
Link: https://patch.msgid.link/20260804125524.740996-1-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
blkdev.h gets included in various places outside the block layer just
for struct blk_plug and related plugging functions.

Split blk_plug into a separate helper to reduce the amount of code
that needs to get rebuilt when blkdev.h changes and to slightly
reduce compile times.

In io_uring this requires pulling in a few other headers explicitly that
previously were implicitly included through blkdev.h.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Christian Brauner (Amutable) &lt;brauner@kernel.org&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Reviewed-by: Damien Le Moal &lt;dlemoal@kernel.org&gt;
Link: https://patch.msgid.link/20260804125524.740996-1-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>posix-cpu-timers: Prevent UAF caused by non-leader exec() race</title>
<updated>2026-07-05T09:44:06+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@kernel.org</email>
</author>
<published>2026-07-03T10:02:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=920f893f735e92ba3a1cd9256899a186b161928d'/>
<id>920f893f735e92ba3a1cd9256899a186b161928d</id>
<content type='text'>
Wongi and Jungwoo decoded and reported a non-leader exec() related race
which can result in an UAF:

 sys_timer_delete()			exec()
   posix_cpu_timer_del()
   // Observes old leader
   p = pid_task(pid, pid_type);		de_thread()
   					  switch_leader();
					  release_task(old_leader)
					    __exit_signal(old_leader)
					      sighand = lock(old_leader, sighand);
					      posix_cpu_timers*_exit();
   sighand = lock_task_sighand(p)	      unhash_task(old_leader);
     sh = lock(p, sighand)	    	      old_leader-&gt;sighand = NULL;
					      unlock(sighand);
     (p-&gt;sighand == NULL)
	unlock(sh)
	return NULL;

   // Returns without action
   if(!sighand)
      return 0;
   free_posix_timer();

This is "harmless" unless the deleted timer was armed and enqueued in
p-&gt;signal because on exec() a TGID targeted timer is inherited.

As sys_timer_delete() freed the underlying posix timer object
run_posix_cpu_timers() or any timerqueue related add/delete operations on
other timers will access the freed object's timerqueue node, which results
in an UAF.

There is a similar problem vs. posix_cpu_timer_set(). For regular posix
timers it just transiently returns -ESRCH to user space, but for the use
case in do_cpu_nanosleep() it's the same UAF just that the k_itimer is
allocated on the stack.

Also posix_cpu_timer_rearm() fails to rearm the timer, which means it stops
to expire.

While debating solutions Frederic pointed out another problem:

   posix_cpu_timer_del(tmr)
					__exit_signal(p)
					  posix_cpu_timers*_exit(p);
					  unhash_task(p);
					  p-&gt;sighand = NULL;
     sh = lock_task_sighand(p)
        sighand = p-&gt;sighand;
	if (!sighand)
	    return NULL;
	lock(sighand);

     if (!sh)
	WARN_ON_ONCE(timer_queued(tmr));

On weakly ordered architectures it is not guaranteed that
posix_cpu_timer_del() will observe the stores in posix_cpu_timers*_exit()
when p-&gt;sighand is observed as NULL, which means the WARN() can be a false
positive.

Solve these issues by:

  1) Changing the store in __exit_signal() to smp_store_release().

  2) Adding a smp_acquire__after_ctrl_dep() into the !sighand path
     of lock_task_sighand().

  3) Creating a helper function for looking up the task and locking sighand
     which does not return when sighand == NULL. Instead it retries the
     task lookup and only if that fails it gives up.

  4) Using that helper in the three affected functions.

#1/#2 ensures that the reader side which observes sighand == NULL also
observes all preceeding stores, i.e. the stores in posix_cpu_timers*_exit()
and the ones in unhash_task().

#3 ensures that the above described non-leader exec() situation is handled
gracefully. When the task lookup returns the old leader, but sighand ==
NULL then it retries. In the non-leader exec() case the subsequent task
lookup will observe the new leader due to #1/#2. In normal exit() scenarios
the subsequent lookup fails.

When the task lookup fails, the function also checks whether the timer is
still enqueued and issues a warning if that's the case. Unfortunately there
is nothing which can be done about it, but as the task is already not
longer visible the timer should not be accessed anymore. This check also
requires memory ordering, which is not provided when the first lookup
fails. To achieve that the check is preceeded by a smp_rmb() which pairs
with the smp_wmb() in write_seqlock() in __exit_signal(). That ensures that
the stores in posix_cpu_timers*_exit() are visible.

The history of the non-leader exec() issue goes back to the early days of
posix CPU timers, which stored a pointer to the group leader task in the
timer. That obviously fails when a non-leader exec() switches the leader.
commit e0a70217107e ("posix-cpu-timers: workaround to suppress the problems
with mt exec") added a temporary workaround for that in 2010 which survived
about 10 years. The fix for the workaround changed the task pointer to a
pid pointer, but failed to see the subtle race described above. So the
Fixes tag picks that commit, which seems to be halfways accurate.

Thanks to Frederic Weissbecker, Oleg Nesterov and Peter Zijlstra for
review, feedback and suggestions and to Wongi and Jungwoo for the excellent
bug report and analysis!

Fixes: 55e8c8eb2c7b ("posix-cpu-timers: Store a reference to a pid not a task")
Reported-by: Wongi Lee &lt;qw3rtyp0@gmail.com&gt;
Reported-by: Jungwoo Lee &lt;jwlee2217@gmail.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@kernel.org&gt;
Reviewed-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: stable@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Wongi and Jungwoo decoded and reported a non-leader exec() related race
which can result in an UAF:

 sys_timer_delete()			exec()
   posix_cpu_timer_del()
   // Observes old leader
   p = pid_task(pid, pid_type);		de_thread()
   					  switch_leader();
					  release_task(old_leader)
					    __exit_signal(old_leader)
					      sighand = lock(old_leader, sighand);
					      posix_cpu_timers*_exit();
   sighand = lock_task_sighand(p)	      unhash_task(old_leader);
     sh = lock(p, sighand)	    	      old_leader-&gt;sighand = NULL;
					      unlock(sighand);
     (p-&gt;sighand == NULL)
	unlock(sh)
	return NULL;

   // Returns without action
   if(!sighand)
      return 0;
   free_posix_timer();

This is "harmless" unless the deleted timer was armed and enqueued in
p-&gt;signal because on exec() a TGID targeted timer is inherited.

As sys_timer_delete() freed the underlying posix timer object
run_posix_cpu_timers() or any timerqueue related add/delete operations on
other timers will access the freed object's timerqueue node, which results
in an UAF.

There is a similar problem vs. posix_cpu_timer_set(). For regular posix
timers it just transiently returns -ESRCH to user space, but for the use
case in do_cpu_nanosleep() it's the same UAF just that the k_itimer is
allocated on the stack.

Also posix_cpu_timer_rearm() fails to rearm the timer, which means it stops
to expire.

While debating solutions Frederic pointed out another problem:

   posix_cpu_timer_del(tmr)
					__exit_signal(p)
					  posix_cpu_timers*_exit(p);
					  unhash_task(p);
					  p-&gt;sighand = NULL;
     sh = lock_task_sighand(p)
        sighand = p-&gt;sighand;
	if (!sighand)
	    return NULL;
	lock(sighand);

     if (!sh)
	WARN_ON_ONCE(timer_queued(tmr));

On weakly ordered architectures it is not guaranteed that
posix_cpu_timer_del() will observe the stores in posix_cpu_timers*_exit()
when p-&gt;sighand is observed as NULL, which means the WARN() can be a false
positive.

Solve these issues by:

  1) Changing the store in __exit_signal() to smp_store_release().

  2) Adding a smp_acquire__after_ctrl_dep() into the !sighand path
     of lock_task_sighand().

  3) Creating a helper function for looking up the task and locking sighand
     which does not return when sighand == NULL. Instead it retries the
     task lookup and only if that fails it gives up.

  4) Using that helper in the three affected functions.

#1/#2 ensures that the reader side which observes sighand == NULL also
observes all preceeding stores, i.e. the stores in posix_cpu_timers*_exit()
and the ones in unhash_task().

#3 ensures that the above described non-leader exec() situation is handled
gracefully. When the task lookup returns the old leader, but sighand ==
NULL then it retries. In the non-leader exec() case the subsequent task
lookup will observe the new leader due to #1/#2. In normal exit() scenarios
the subsequent lookup fails.

When the task lookup fails, the function also checks whether the timer is
still enqueued and issues a warning if that's the case. Unfortunately there
is nothing which can be done about it, but as the task is already not
longer visible the timer should not be accessed anymore. This check also
requires memory ordering, which is not provided when the first lookup
fails. To achieve that the check is preceeded by a smp_rmb() which pairs
with the smp_wmb() in write_seqlock() in __exit_signal(). That ensures that
the stores in posix_cpu_timers*_exit() are visible.

The history of the non-leader exec() issue goes back to the early days of
posix CPU timers, which stored a pointer to the group leader task in the
timer. That obviously fails when a non-leader exec() switches the leader.
commit e0a70217107e ("posix-cpu-timers: workaround to suppress the problems
with mt exec") added a temporary workaround for that in 2010 which survived
about 10 years. The fix for the workaround changed the task pointer to a
pid pointer, but failed to see the subtle race described above. So the
Fixes tag picks that commit, which seems to be halfways accurate.

Thanks to Frederic Weissbecker, Oleg Nesterov and Peter Zijlstra for
review, feedback and suggestions and to Wongi and Jungwoo for the excellent
bug report and analysis!

Fixes: 55e8c8eb2c7b ("posix-cpu-timers: Store a reference to a pid not a task")
Reported-by: Wongi Lee &lt;qw3rtyp0@gmail.com&gt;
Reported-by: Jungwoo Lee &lt;jwlee2217@gmail.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@kernel.org&gt;
Reviewed-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: stable@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>kernel: exit: fix coding style missing spaces</title>
<updated>2026-06-29T08:29:22+00:00</updated>
<author>
<name>mingzhu wang</name>
<email>mingzhu.wang@transsion.com</email>
</author>
<published>2026-06-09T02:15:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d7337cad4dbe6caf9535d3539daed353dd425dc1'/>
<id>d7337cad4dbe6caf9535d3539daed353dd425dc1</id>
<content type='text'>
Add spaces around bitwise AND and shift operators in sys_exit()
to comply with the Linux kernel coding style.

Signed-off-by: mingzhu wang &lt;mingzhu.wang@transsion.com&gt;
Link: https://patch.msgid.link/20260609021436.1739-1-mingzhu.wang@transsion.com
Signed-off-by: Christian Brauner (Amutable) &lt;brauner@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add spaces around bitwise AND and shift operators in sys_exit()
to comply with the Linux kernel coding style.

Signed-off-by: mingzhu wang &lt;mingzhu.wang@transsion.com&gt;
Link: https://patch.msgid.link/20260609021436.1739-1-mingzhu.wang@transsion.com
Signed-off-by: Christian Brauner (Amutable) &lt;brauner@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'sched-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip</title>
<updated>2026-06-15T09:20:18+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-06-15T09:20:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2cbf335f8ccc7a6418159858dc03e36df8e3e5cf'/>
<id>2cbf335f8ccc7a6418159858dc03e36df8e3e5cf</id>
<content type='text'>
Pull scheduler updates from Ingo Molnar:
 "SMP load-balancing updates:

   - A large series to introduce infrastructure for cache-aware load
     balancing, with the goal of co-locating tasks that share data
     within the same Last Level Cache (LLC) domain. By improving cache
     locality, the scheduler can reduce cache bouncing and cache misses,
     ultimately improving data access efficiency.

     Implemented by Chen Yu and Tim Chen, based on early prototype work
     by Peter Zijlstra, with fixes by Jianyong Wu, Peter Zijlstra and
     Shrikanth Hegde.

   - A series to simplify CONFIG_SCHED_SMT ifdef usage (Shrikanth Hegde)

  Fair scheduler updates:

   - A series to improve SD_ASYM_CPUCAPACITY scheduling by introducing
     SMT awareness (Andrea Righi, K Prateek Nayak)

   - A series to optimize cfs_rq and sched_entity allocation for better
     data locality (Zecheng Li)

   - A preparatory series to change fair/cgroup scheduling to a single
     runqueue, without the final change (Peter Zijlstra)

   - Auto-manage ext/fair dl_server bandwidth (Andrea Righi)

   - Fix cpu_util runnable_avg arithmetic (Hongyan Xia)

   - Optimize update_tg_load_avg()'s rate-limiting code (Rik van Riel)

   - Allow account_cfs_rq_runtime() to throttle current hierarchy
     (K Prateek Nayak)

   - Update util_est after updating util_avg during dequeue, to fix the
     util signal update logic, which reduces signal noise (Vincent
     Guittot)

  Scheduler topology updates:

   - Allow multiple domains to claim sched_domain_shared (K Prateek
     Nayak)

   - Add parameter to split LLC (Peter Zijlstra)

  Core scheduler updates:

   - Use trace_call__&lt;tp&gt;() to save a static branch (Gabriele Monaco)

  Scheduler statistics updates:

   - Drop now-stale mul_u64_u64_div_u64() cputime over-approximation
     guard (Nicolas Pitre)

  Deadline scheduler updates:

   - Reject debugfs dl_server writes for offline CPUs (Andrea Righi)

   - Fix replenishment logic for non-deferred servers (Yuri Andriaccio)

  RT scheduling updates:

   - Turn RT_PUSH_IPI default off for non PREEMPT_RT (Steven Rostedt)

   - Update default bandwidth for real-time tasks to 1.0 (Yuri
     Andriaccio)

  Proxy scheduling updates:

   - A series to implement Optimized Donor Migration for Proxy Execution
     (John Stultz, Peter Zijlstra)

   - Various proxy scheduling cleanups and fixes (Peter Zijlstra,
     K Prateek Nayak)

  Misc fixes, improvements and cleanups by Aaron Lu, Andrea Righi,
  Zenghui Yu, Chen Yu, Guanyou.Chen, John Stultz, Shrikanth Hegde,
  Peter Zijlstra, Liang Luo and Yiyang Chen"

* tag 'sched-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (91 commits)
  sched/fair: Fix newidle vs core-sched
  sched/deadline: Use task_on_rq_migrating() helper
  sched/core: Combine separate 'else' and 'if' statements
  sched/fair: Fix cpu_util runnable_avg arithmetic
  sched/fair: Unify cfs_rq throttling via account_cfs_rq_runtime()
  sched/fair: Move the throttled tasks to a local list in tg_unthrottle_up()
  sched/fair: Call update_curr() before unthrottling the hierarchy
  sched/fair: Use throttled_csd_list for local unthrottle
  sched/fair: Convert cfs bandwidth throttling to use guards
  sched/fair: Allocate cfs_tg_state with percpu allocator
  sched/fair: Remove task_group-&gt;se pointer array
  sched/fair: Co-locate cfs_rq and sched_entity in cfs_tg_state
  sched: restore timer_slack_ns when resetting RT policy on fork
  MAINTAINERS: Fix spelling mistake in Peter's name
  sched: Simplify ttwu_runnable()
  sched/proxy: Remove superfluous clear_task_blocked_in()
  sched/proxy: Remove PROXY_WAKING
  sched/proxy: Switch proxy to use p-&gt;is_blocked
  sched/proxy: Only return migrate when needed
  sched: Be more strict about p-&gt;is_blocked
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull scheduler updates from Ingo Molnar:
 "SMP load-balancing updates:

   - A large series to introduce infrastructure for cache-aware load
     balancing, with the goal of co-locating tasks that share data
     within the same Last Level Cache (LLC) domain. By improving cache
     locality, the scheduler can reduce cache bouncing and cache misses,
     ultimately improving data access efficiency.

     Implemented by Chen Yu and Tim Chen, based on early prototype work
     by Peter Zijlstra, with fixes by Jianyong Wu, Peter Zijlstra and
     Shrikanth Hegde.

   - A series to simplify CONFIG_SCHED_SMT ifdef usage (Shrikanth Hegde)

  Fair scheduler updates:

   - A series to improve SD_ASYM_CPUCAPACITY scheduling by introducing
     SMT awareness (Andrea Righi, K Prateek Nayak)

   - A series to optimize cfs_rq and sched_entity allocation for better
     data locality (Zecheng Li)

   - A preparatory series to change fair/cgroup scheduling to a single
     runqueue, without the final change (Peter Zijlstra)

   - Auto-manage ext/fair dl_server bandwidth (Andrea Righi)

   - Fix cpu_util runnable_avg arithmetic (Hongyan Xia)

   - Optimize update_tg_load_avg()'s rate-limiting code (Rik van Riel)

   - Allow account_cfs_rq_runtime() to throttle current hierarchy
     (K Prateek Nayak)

   - Update util_est after updating util_avg during dequeue, to fix the
     util signal update logic, which reduces signal noise (Vincent
     Guittot)

  Scheduler topology updates:

   - Allow multiple domains to claim sched_domain_shared (K Prateek
     Nayak)

   - Add parameter to split LLC (Peter Zijlstra)

  Core scheduler updates:

   - Use trace_call__&lt;tp&gt;() to save a static branch (Gabriele Monaco)

  Scheduler statistics updates:

   - Drop now-stale mul_u64_u64_div_u64() cputime over-approximation
     guard (Nicolas Pitre)

  Deadline scheduler updates:

   - Reject debugfs dl_server writes for offline CPUs (Andrea Righi)

   - Fix replenishment logic for non-deferred servers (Yuri Andriaccio)

  RT scheduling updates:

   - Turn RT_PUSH_IPI default off for non PREEMPT_RT (Steven Rostedt)

   - Update default bandwidth for real-time tasks to 1.0 (Yuri
     Andriaccio)

  Proxy scheduling updates:

   - A series to implement Optimized Donor Migration for Proxy Execution
     (John Stultz, Peter Zijlstra)

   - Various proxy scheduling cleanups and fixes (Peter Zijlstra,
     K Prateek Nayak)

  Misc fixes, improvements and cleanups by Aaron Lu, Andrea Righi,
  Zenghui Yu, Chen Yu, Guanyou.Chen, John Stultz, Shrikanth Hegde,
  Peter Zijlstra, Liang Luo and Yiyang Chen"

* tag 'sched-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (91 commits)
  sched/fair: Fix newidle vs core-sched
  sched/deadline: Use task_on_rq_migrating() helper
  sched/core: Combine separate 'else' and 'if' statements
  sched/fair: Fix cpu_util runnable_avg arithmetic
  sched/fair: Unify cfs_rq throttling via account_cfs_rq_runtime()
  sched/fair: Move the throttled tasks to a local list in tg_unthrottle_up()
  sched/fair: Call update_curr() before unthrottling the hierarchy
  sched/fair: Use throttled_csd_list for local unthrottle
  sched/fair: Convert cfs bandwidth throttling to use guards
  sched/fair: Allocate cfs_tg_state with percpu allocator
  sched/fair: Remove task_group-&gt;se pointer array
  sched/fair: Co-locate cfs_rq and sched_entity in cfs_tg_state
  sched: restore timer_slack_ns when resetting RT policy on fork
  MAINTAINERS: Fix spelling mistake in Peter's name
  sched: Simplify ttwu_runnable()
  sched/proxy: Remove superfluous clear_task_blocked_in()
  sched/proxy: Remove PROXY_WAKING
  sched/proxy: Switch proxy to use p-&gt;is_blocked
  sched/proxy: Only return migrate when needed
  sched: Be more strict about p-&gt;is_blocked
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip</title>
<updated>2026-06-15T08:51:14+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-06-15T08:51:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=764e77d868a5b932c709e20ddb5993f9111a841c'/>
<id>764e77d868a5b932c709e20ddb5993f9111a841c</id>
<content type='text'>
Pull locking updates from Ingo Molnar:
 "Futex updates:

   - Optimize futex hash bucket access patterns (Peter Zijlstra)

   - Large series to address the robust futex unlock race for real, by
     Thomas Gleixner:

      "The robust futex unlock mechanism is racy in respect to the
       clearing of the robust_list_head::list_op_pending pointer because
       unlock and clearing the pointer are not atomic.

       The race window is between the unlock and clearing the pending op
       pointer. If the task is forced to exit in this window, exit will
       access a potentially invalid pending op pointer when cleaning up
       the robust list.

       That happens if another task manages to unmap the object
       containing the lock before the cleanup, which results in an UAF.

       In the worst case this UAF can lead to memory corruption when
       unrelated content has been mapped to the same address by the time
       the access happens.

       User space can't solve this problem without help from the kernel.
       This series provides the kernel side infrastructure to help it
       along:

        1) Combined unlock, pointer clearing, wake-up for the
           contended case

        2) VDSO based unlock and pointer clearing helpers with a
           fix-up function in the kernel when user space was interrupted
           within the critical section.

      ... with help by André Almeida:

        - Add a note about robust list race condition (André Almeida)
        - Add self-tests for robust release operations (André Almeida)

  Context analysis updates:

   - Implement context analysis for 'struct rt_mutex'. (Bart Van Assche)
   - Bump required Clang version to 23 (Marco Elver)

  Guard infrastructure updates:

   - Series to remove NULL check from unconditional guards (Dmitry
     Ilvokhin)

  Lockdep updates:

   - Restore self-test migrate_disable() and sched_rt_mutex state on
     PREEMPT_RT (Karl Mehltretter)

  Membarriers updates:

   - Use per-CPU mutexes for targeted commands (Aniket Gattani)
   - Modernize membarrier_global_expedited with cleanup guards (Aniket
     Gattani)
   - Add rseq stress test for CFS throttle interactions (Aniket Gattani)

  percpu-rwsems updates:

   - Extract __percpu_up_read() to optimize inlining overhead (Dmitry
     Ilvokhin)

  Seqlocks updates:

   - Allow UBSAN_ALIGNMENT to fail optimizing (Heiko Carstens)

  Lock tracing:

   - Add contended_release tracepoint to sleepable locks such as
     mutexes, percpu-rwsems, rtmutexes, rwsems and semaphores (Dmitry
     Ilvokhin)

  MAINTAINERS updates:

   - MAINTAINERS: Add RUST [SYNC] entry (Boqun Feng)

  Misc updates and fixes by Randy Dunlap, YE WEI-HONG, Fabricio Parra,
  Dmitry Ilvokhin and Peter Zijlstra"

* tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (36 commits)
  locking: Add contended_release tracepoint to sleepable locks
  locking/percpu-rwsem: Extract __percpu_up_read()
  tracing/lock: Remove unnecessary linux/sched.h include
  futex: Optimize futex hash bucket access patterns
  rust: sync: completion: Mark inline complete_all and wait_for_completion
  MAINTAINERS: Add RUST [SYNC] entry
  cleanup: Specify nonnull argument index
  selftests: futex: Add tests for robust release operations
  Documentation: futex: Add a note about robust list race condition
  x86/vdso: Implement __vdso_futex_robust_try_unlock()
  x86/vdso: Prepare for robust futex unlock support
  futex: Provide infrastructure to plug the non contended robust futex unlock race
  futex: Add robust futex unlock IP range
  futex: Add support for unlocking robust futexes
  futex: Cleanup UAPI defines
  x86: Select ARCH_MEMORY_ORDER_TSO
  uaccess: Provide unsafe_atomic_store_release_user()
  futex: Provide UABI defines for robust list entry modifiers
  futex: Move futex related mm_struct data into a struct
  futex: Make futex_mm_init() void
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull locking updates from Ingo Molnar:
 "Futex updates:

   - Optimize futex hash bucket access patterns (Peter Zijlstra)

   - Large series to address the robust futex unlock race for real, by
     Thomas Gleixner:

      "The robust futex unlock mechanism is racy in respect to the
       clearing of the robust_list_head::list_op_pending pointer because
       unlock and clearing the pointer are not atomic.

       The race window is between the unlock and clearing the pending op
       pointer. If the task is forced to exit in this window, exit will
       access a potentially invalid pending op pointer when cleaning up
       the robust list.

       That happens if another task manages to unmap the object
       containing the lock before the cleanup, which results in an UAF.

       In the worst case this UAF can lead to memory corruption when
       unrelated content has been mapped to the same address by the time
       the access happens.

       User space can't solve this problem without help from the kernel.
       This series provides the kernel side infrastructure to help it
       along:

        1) Combined unlock, pointer clearing, wake-up for the
           contended case

        2) VDSO based unlock and pointer clearing helpers with a
           fix-up function in the kernel when user space was interrupted
           within the critical section.

      ... with help by André Almeida:

        - Add a note about robust list race condition (André Almeida)
        - Add self-tests for robust release operations (André Almeida)

  Context analysis updates:

   - Implement context analysis for 'struct rt_mutex'. (Bart Van Assche)
   - Bump required Clang version to 23 (Marco Elver)

  Guard infrastructure updates:

   - Series to remove NULL check from unconditional guards (Dmitry
     Ilvokhin)

  Lockdep updates:

   - Restore self-test migrate_disable() and sched_rt_mutex state on
     PREEMPT_RT (Karl Mehltretter)

  Membarriers updates:

   - Use per-CPU mutexes for targeted commands (Aniket Gattani)
   - Modernize membarrier_global_expedited with cleanup guards (Aniket
     Gattani)
   - Add rseq stress test for CFS throttle interactions (Aniket Gattani)

  percpu-rwsems updates:

   - Extract __percpu_up_read() to optimize inlining overhead (Dmitry
     Ilvokhin)

  Seqlocks updates:

   - Allow UBSAN_ALIGNMENT to fail optimizing (Heiko Carstens)

  Lock tracing:

   - Add contended_release tracepoint to sleepable locks such as
     mutexes, percpu-rwsems, rtmutexes, rwsems and semaphores (Dmitry
     Ilvokhin)

  MAINTAINERS updates:

   - MAINTAINERS: Add RUST [SYNC] entry (Boqun Feng)

  Misc updates and fixes by Randy Dunlap, YE WEI-HONG, Fabricio Parra,
  Dmitry Ilvokhin and Peter Zijlstra"

* tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (36 commits)
  locking: Add contended_release tracepoint to sleepable locks
  locking/percpu-rwsem: Extract __percpu_up_read()
  tracing/lock: Remove unnecessary linux/sched.h include
  futex: Optimize futex hash bucket access patterns
  rust: sync: completion: Mark inline complete_all and wait_for_completion
  MAINTAINERS: Add RUST [SYNC] entry
  cleanup: Specify nonnull argument index
  selftests: futex: Add tests for robust release operations
  Documentation: futex: Add a note about robust list race condition
  x86/vdso: Implement __vdso_futex_robust_try_unlock()
  x86/vdso: Prepare for robust futex unlock support
  futex: Provide infrastructure to plug the non contended robust futex unlock race
  futex: Add robust futex unlock IP range
  futex: Add support for unlocking robust futexes
  futex: Cleanup UAPI defines
  x86: Select ARCH_MEMORY_ORDER_TSO
  uaccess: Provide unsafe_atomic_store_release_user()
  futex: Provide UABI defines for robust list entry modifiers
  futex: Move futex related mm_struct data into a struct
  futex: Make futex_mm_init() void
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>futex: Move futex task related data into a struct</title>
<updated>2026-06-03T09:38:49+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@kernel.org</email>
</author>
<published>2026-06-02T09:09:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c1ffc9c6e4f8a13dd68e97920c9a24d095c6e41a'/>
<id>c1ffc9c6e4f8a13dd68e97920c9a24d095c6e41a</id>
<content type='text'>
Having all these members in task_struct along with the required #ifdeffery
is annoying, does not allow efficient initializing of the data with
memset() and makes extending it tedious.

Move it into a data structure and fix up all usage sites.

Signed-off-by: Thomas Gleixner &lt;tglx@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-by: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Reviewed-by: André Almeida &lt;andrealmeid@igalia.com&gt;
Link: https://patch.msgid.link/20260602090535.308220888@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Having all these members in task_struct along with the required #ifdeffery
is annoying, does not allow efficient initializing of the data with
memset() and makes extending it tedious.

Move it into a data structure and fix up all usage sites.

Signed-off-by: Thomas Gleixner &lt;tglx@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-by: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Reviewed-by: André Almeida &lt;andrealmeid@igalia.com&gt;
Link: https://patch.msgid.link/20260602090535.308220888@kernel.org
</pre>
</div>
</content>
</entry>
</feed>
