<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/linux, branch v6.4.8</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>dma-buf: keep the signaling time of merged fences v3</title>
<updated>2023-08-03T08:26:14+00:00</updated>
<author>
<name>Christian König</name>
<email>christian.koenig@amd.com</email>
</author>
<published>2023-06-13T08:09:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6bd9952eade5bbcd099083ca782ad674f6b32637'/>
<id>6bd9952eade5bbcd099083ca782ad674f6b32637</id>
<content type='text'>
commit f781f661e8c99b0cb34129f2e374234d61864e77 upstream.

Some Android CTS is testing if the signaling time keeps consistent
during merges.

v2: use the current time if the fence is still in the signaling path and
the timestamp not yet available.
v3: improve comment, fix one more case to use the correct timestamp

Signed-off-by: Christian König &lt;christian.koenig@amd.com&gt;
Reviewed-by: Luben Tuikov &lt;luben.tuikov@amd.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230630120041.109216-1-christian.koenig@amd.com
Cc: Jindong Yue &lt;jindong.yue@nxp.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f781f661e8c99b0cb34129f2e374234d61864e77 upstream.

Some Android CTS is testing if the signaling time keeps consistent
during merges.

v2: use the current time if the fence is still in the signaling path and
the timestamp not yet available.
v3: improve comment, fix one more case to use the correct timestamp

Signed-off-by: Christian König &lt;christian.koenig@amd.com&gt;
Reviewed-by: Luben Tuikov &lt;luben.tuikov@amd.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230630120041.109216-1-christian.koenig@amd.com
Cc: Jindong Yue &lt;jindong.yue@nxp.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: fix memory ordering for mm_lock_seq and vm_lock_seq</title>
<updated>2023-08-03T08:26:14+00:00</updated>
<author>
<name>Jann Horn</name>
<email>jannh@google.com</email>
</author>
<published>2023-07-21T22:51:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bdb3106af2b26e8f10dee7353f0ef63bf84fd6de'/>
<id>bdb3106af2b26e8f10dee7353f0ef63bf84fd6de</id>
<content type='text'>
commit b1f02b95758d05b799731d939e76a0bd6da312db upstream.

mm-&gt;mm_lock_seq effectively functions as a read/write lock; therefore it
must be used with acquire/release semantics.

A specific example is the interaction between userfaultfd_register() and
lock_vma_under_rcu().

userfaultfd_register() does the following from the point where it changes
a VMA's flags to the point where concurrent readers are permitted again
(in a simple scenario where only a single private VMA is accessed and no
merging/splitting is involved):

userfaultfd_register
  userfaultfd_set_vm_flags
    vm_flags_reset
      vma_start_write
        down_write(&amp;vma-&gt;vm_lock-&gt;lock)
        vma-&gt;vm_lock_seq = mm_lock_seq [marks VMA as busy]
        up_write(&amp;vma-&gt;vm_lock-&gt;lock)
      vm_flags_init
        [sets VM_UFFD_* in __vm_flags]
  vma-&gt;vm_userfaultfd_ctx.ctx = ctx
  mmap_write_unlock
    vma_end_write_all
      WRITE_ONCE(mm-&gt;mm_lock_seq, mm-&gt;mm_lock_seq + 1) [unlocks VMA]

There are no memory barriers in between the __vm_flags update and the
mm-&gt;mm_lock_seq update that unlocks the VMA, so the unlock can be
reordered to above the `vm_flags_init()` call, which means from the
perspective of a concurrent reader, a VMA can be marked as a userfaultfd
VMA while it is not VMA-locked.  That's bad, we definitely need a
store-release for the unlock operation.

The non-atomic write to vma-&gt;vm_lock_seq in vma_start_write() is mostly
fine because all accesses to vma-&gt;vm_lock_seq that matter are always
protected by the VMA lock.  There is a racy read in vma_start_read()
though that can tolerate false-positives, so we should be using
WRITE_ONCE() to keep things tidy and data-race-free (including for KCSAN).

On the other side, lock_vma_under_rcu() works as follows in the relevant
region for locking and userfaultfd check:

lock_vma_under_rcu
  vma_start_read
    vma-&gt;vm_lock_seq == READ_ONCE(vma-&gt;vm_mm-&gt;mm_lock_seq) [early bailout]
    down_read_trylock(&amp;vma-&gt;vm_lock-&gt;lock)
    vma-&gt;vm_lock_seq == READ_ONCE(vma-&gt;vm_mm-&gt;mm_lock_seq) [main check]
  userfaultfd_armed
    checks vma-&gt;vm_flags &amp; __VM_UFFD_FLAGS

Here, the interesting aspect is how far down the mm-&gt;mm_lock_seq read can
be reordered - if this read is reordered down below the vma-&gt;vm_flags
access, this could cause lock_vma_under_rcu() to partly operate on
information that was read while the VMA was supposed to be locked.  To
prevent this kind of downwards bleeding of the mm-&gt;mm_lock_seq read, we
need to read it with a load-acquire.

Some of the comment wording is based on suggestions by Suren.

BACKPORT WARNING: One of the functions changed by this patch (which I've
written against Linus' tree) is vma_try_start_write(), but this function
no longer exists in mm/mm-everything.  I don't know whether the merged
version of this patch will be ordered before or after the patch that
removes vma_try_start_write().  If you're backporting this patch to a tree
with vma_try_start_write(), make sure this patch changes that function.

Link: https://lkml.kernel.org/r/20230721225107.942336-1-jannh@google.com
Fixes: 5e31275cc997 ("mm: add per-VMA lock and helper functions to control it")
Signed-off-by: Jann Horn &lt;jannh@google.com&gt;
Reviewed-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b1f02b95758d05b799731d939e76a0bd6da312db upstream.

mm-&gt;mm_lock_seq effectively functions as a read/write lock; therefore it
must be used with acquire/release semantics.

A specific example is the interaction between userfaultfd_register() and
lock_vma_under_rcu().

userfaultfd_register() does the following from the point where it changes
a VMA's flags to the point where concurrent readers are permitted again
(in a simple scenario where only a single private VMA is accessed and no
merging/splitting is involved):

userfaultfd_register
  userfaultfd_set_vm_flags
    vm_flags_reset
      vma_start_write
        down_write(&amp;vma-&gt;vm_lock-&gt;lock)
        vma-&gt;vm_lock_seq = mm_lock_seq [marks VMA as busy]
        up_write(&amp;vma-&gt;vm_lock-&gt;lock)
      vm_flags_init
        [sets VM_UFFD_* in __vm_flags]
  vma-&gt;vm_userfaultfd_ctx.ctx = ctx
  mmap_write_unlock
    vma_end_write_all
      WRITE_ONCE(mm-&gt;mm_lock_seq, mm-&gt;mm_lock_seq + 1) [unlocks VMA]

There are no memory barriers in between the __vm_flags update and the
mm-&gt;mm_lock_seq update that unlocks the VMA, so the unlock can be
reordered to above the `vm_flags_init()` call, which means from the
perspective of a concurrent reader, a VMA can be marked as a userfaultfd
VMA while it is not VMA-locked.  That's bad, we definitely need a
store-release for the unlock operation.

The non-atomic write to vma-&gt;vm_lock_seq in vma_start_write() is mostly
fine because all accesses to vma-&gt;vm_lock_seq that matter are always
protected by the VMA lock.  There is a racy read in vma_start_read()
though that can tolerate false-positives, so we should be using
WRITE_ONCE() to keep things tidy and data-race-free (including for KCSAN).

On the other side, lock_vma_under_rcu() works as follows in the relevant
region for locking and userfaultfd check:

lock_vma_under_rcu
  vma_start_read
    vma-&gt;vm_lock_seq == READ_ONCE(vma-&gt;vm_mm-&gt;mm_lock_seq) [early bailout]
    down_read_trylock(&amp;vma-&gt;vm_lock-&gt;lock)
    vma-&gt;vm_lock_seq == READ_ONCE(vma-&gt;vm_mm-&gt;mm_lock_seq) [main check]
  userfaultfd_armed
    checks vma-&gt;vm_flags &amp; __VM_UFFD_FLAGS

Here, the interesting aspect is how far down the mm-&gt;mm_lock_seq read can
be reordered - if this read is reordered down below the vma-&gt;vm_flags
access, this could cause lock_vma_under_rcu() to partly operate on
information that was read while the VMA was supposed to be locked.  To
prevent this kind of downwards bleeding of the mm-&gt;mm_lock_seq read, we
need to read it with a load-acquire.

Some of the comment wording is based on suggestions by Suren.

BACKPORT WARNING: One of the functions changed by this patch (which I've
written against Linus' tree) is vma_try_start_write(), but this function
no longer exists in mm/mm-everything.  I don't know whether the merged
version of this patch will be ordered before or after the patch that
removes vma_try_start_write().  If you're backporting this patch to a tree
with vma_try_start_write(), make sure this patch changes that function.

Link: https://lkml.kernel.org/r/20230721225107.942336-1-jannh@google.com
Fixes: 5e31275cc997 ("mm: add per-VMA lock and helper functions to control it")
Signed-off-by: Jann Horn &lt;jannh@google.com&gt;
Reviewed-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tcp: annotate data-races around fastopenq.max_qlen</title>
<updated>2023-07-27T06:57:05+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2023-07-19T21:28:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4a6ebe88cd96f2ce7f020bb9bd5460eefa6a5a8e'/>
<id>4a6ebe88cd96f2ce7f020bb9bd5460eefa6a5a8e</id>
<content type='text'>
[ Upstream commit 70f360dd7042cb843635ece9d28335a4addff9eb ]

This field can be read locklessly.

Fixes: 1536e2857bd3 ("tcp: Add a TCP_FASTOPEN socket option to get a max backlog on its listner")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://lore.kernel.org/r/20230719212857.3943972-12-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 70f360dd7042cb843635ece9d28335a4addff9eb ]

This field can be read locklessly.

Fixes: 1536e2857bd3 ("tcp: Add a TCP_FASTOPEN socket option to get a max backlog on its listner")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://lore.kernel.org/r/20230719212857.3943972-12-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>sched/psi: use kernfs polling functions for PSI trigger polling</title>
<updated>2023-07-27T06:56:53+00:00</updated>
<author>
<name>Suren Baghdasaryan</name>
<email>surenb@google.com</email>
</author>
<published>2023-06-30T00:56:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d124ab17024cc85a1079b7810a018a497ebc13da'/>
<id>d124ab17024cc85a1079b7810a018a497ebc13da</id>
<content type='text'>
[ Upstream commit aff037078ecaecf34a7c2afab1341815f90fba5e ]

Destroying psi trigger in cgroup_file_release causes UAF issues when
a cgroup is removed from under a polling process. This is happening
because cgroup removal causes a call to cgroup_file_release while the
actual file is still alive. Destroying the trigger at this point would
also destroy its waitqueue head and if there is still a polling process
on that file accessing the waitqueue, it will step on the freed pointer:

do_select
  vfs_poll
                           do_rmdir
                             cgroup_rmdir
                               kernfs_drain_open_files
                                 cgroup_file_release
                                   cgroup_pressure_release
                                     psi_trigger_destroy
                                       wake_up_pollfree(&amp;t-&gt;event_wait)
// vfs_poll is unblocked
                                       synchronize_rcu
                                       kfree(t)
  poll_freewait -&gt; UAF access to the trigger's waitqueue head

Patch [1] fixed this issue for epoll() case using wake_up_pollfree(),
however the same issue exists for synchronous poll() case.
The root cause of this issue is that the lifecycles of the psi trigger's
waitqueue and of the file associated with the trigger are different. Fix
this by using kernfs_generic_poll function when polling on cgroup-specific
psi triggers. It internally uses kernfs_open_node-&gt;poll waitqueue head
with its lifecycle tied to the file's lifecycle. This also renders the
fix in [1] obsolete, so revert it.

[1] commit c2dbe32d5db5 ("sched/psi: Fix use-after-free in ep_remove_wait_queue()")

Fixes: 0e94682b73bf ("psi: introduce psi monitor")
Closes: https://lore.kernel.org/all/20230613062306.101831-1-lujialin4@huawei.com/
Reported-by: Lu Jialin &lt;lujialin4@huawei.com&gt;
Signed-off-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/20230630005612.1014540-1-surenb@google.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit aff037078ecaecf34a7c2afab1341815f90fba5e ]

Destroying psi trigger in cgroup_file_release causes UAF issues when
a cgroup is removed from under a polling process. This is happening
because cgroup removal causes a call to cgroup_file_release while the
actual file is still alive. Destroying the trigger at this point would
also destroy its waitqueue head and if there is still a polling process
on that file accessing the waitqueue, it will step on the freed pointer:

do_select
  vfs_poll
                           do_rmdir
                             cgroup_rmdir
                               kernfs_drain_open_files
                                 cgroup_file_release
                                   cgroup_pressure_release
                                     psi_trigger_destroy
                                       wake_up_pollfree(&amp;t-&gt;event_wait)
// vfs_poll is unblocked
                                       synchronize_rcu
                                       kfree(t)
  poll_freewait -&gt; UAF access to the trigger's waitqueue head

Patch [1] fixed this issue for epoll() case using wake_up_pollfree(),
however the same issue exists for synchronous poll() case.
The root cause of this issue is that the lifecycles of the psi trigger's
waitqueue and of the file associated with the trigger are different. Fix
this by using kernfs_generic_poll function when polling on cgroup-specific
psi triggers. It internally uses kernfs_open_node-&gt;poll waitqueue head
with its lifecycle tied to the file's lifecycle. This also renders the
fix in [1] obsolete, so revert it.

[1] commit c2dbe32d5db5 ("sched/psi: Fix use-after-free in ep_remove_wait_queue()")

Fixes: 0e94682b73bf ("psi: introduce psi monitor")
Closes: https://lore.kernel.org/all/20230613062306.101831-1-lujialin4@huawei.com/
Reported-by: Lu Jialin &lt;lujialin4@huawei.com&gt;
Signed-off-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/20230630005612.1014540-1-surenb@google.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>posix-timers: Ensure timer ID search-loop limit is valid</title>
<updated>2023-07-27T06:56:45+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2023-06-01T18:58:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=37175e25edf7cc0d5a2cd2c2a1cbe2dcbf4a1937'/>
<id>37175e25edf7cc0d5a2cd2c2a1cbe2dcbf4a1937</id>
<content type='text'>
[ Upstream commit 8ce8849dd1e78dadcee0ec9acbd259d239b7069f ]

posix_timer_add() tries to allocate a posix timer ID by starting from the
cached ID which was stored by the last successful allocation.

This is done in a loop searching the ID space for a free slot one by
one. The loop has to terminate when the search wrapped around to the
starting point.

But that's racy vs. establishing the starting point. That is read out
lockless, which leads to the following problem:

CPU0	  	      	     	   CPU1
posix_timer_add()
  start = sig-&gt;posix_timer_id;
  lock(hash_lock);
  ...				   posix_timer_add()
  if (++sig-&gt;posix_timer_id &lt; 0)
      			             start = sig-&gt;posix_timer_id;
     sig-&gt;posix_timer_id = 0;

So CPU1 can observe a negative start value, i.e. -1, and the loop break
never happens because the condition can never be true:

  if (sig-&gt;posix_timer_id == start)
     break;

While this is unlikely to ever turn into an endless loop as the ID space is
huge (INT_MAX), the racy read of the start value caught the attention of
KCSAN and Dmitry unearthed that incorrectness.

Rewrite it so that all id operations are under the hash lock.

Reported-by: syzbot+5c54bd3eb218bb595aa9@syzkaller.appspotmail.com
Reported-by: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Frederic Weisbecker &lt;frederic@kernel.org&gt;
Link: https://lore.kernel.org/r/87bkhzdn6g.ffs@tglx
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 8ce8849dd1e78dadcee0ec9acbd259d239b7069f ]

posix_timer_add() tries to allocate a posix timer ID by starting from the
cached ID which was stored by the last successful allocation.

This is done in a loop searching the ID space for a free slot one by
one. The loop has to terminate when the search wrapped around to the
starting point.

But that's racy vs. establishing the starting point. That is read out
lockless, which leads to the following problem:

CPU0	  	      	     	   CPU1
posix_timer_add()
  start = sig-&gt;posix_timer_id;
  lock(hash_lock);
  ...				   posix_timer_add()
  if (++sig-&gt;posix_timer_id &lt; 0)
      			             start = sig-&gt;posix_timer_id;
     sig-&gt;posix_timer_id = 0;

So CPU1 can observe a negative start value, i.e. -1, and the loop break
never happens because the condition can never be true:

  if (sig-&gt;posix_timer_id == start)
     break;

While this is unlikely to ever turn into an endless loop as the ID space is
huge (INT_MAX), the racy read of the start value caught the attention of
KCSAN and Dmitry unearthed that incorrectness.

Rewrite it so that all id operations are under the hash lock.

Reported-by: syzbot+5c54bd3eb218bb595aa9@syzkaller.appspotmail.com
Reported-by: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Frederic Weisbecker &lt;frederic@kernel.org&gt;
Link: https://lore.kernel.org/r/87bkhzdn6g.ffs@tglx
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fprobe: Ensure running fprobe_exit_handler() finished before calling rethook_free()</title>
<updated>2023-07-23T11:54:12+00:00</updated>
<author>
<name>Masami Hiramatsu (Google)</name>
<email>mhiramat@kernel.org</email>
</author>
<published>2023-07-07T14:03:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=af2c39d87fcf624948c13877a5bc61198d4826f7'/>
<id>af2c39d87fcf624948c13877a5bc61198d4826f7</id>
<content type='text'>
commit 195b9cb5b288fec1c871ef89f78cc9a7461aad3a upstream.

Ensure running fprobe_exit_handler() has finished before
calling rethook_free() in the unregister_fprobe() so that caller can free
the fprobe right after unregister_fprobe().

unregister_fprobe() ensured that all running fprobe_entry/exit_handler()
have finished by calling unregister_ftrace_function() which synchronizes
RCU. But commit 5f81018753df ("fprobe: Release rethook after the ftrace_ops
is unregistered") changed to call rethook_free() after
unregister_ftrace_function(). So call rethook_stop() to make rethook
disabled before unregister_ftrace_function() and ensure it again.

Here is the possible code flow that can call the exit handler after
unregister_fprobe().

------
 CPU1                              CPU2
 call unregister_fprobe(fp)
 ...
                                   __fprobe_handler()
                                   rethook_hook() on probed function
 unregister_ftrace_function()
                                   return from probed function
                                   rethook hooks
                                   find rh-&gt;handler == fprobe_exit_handler
                                   call fprobe_exit_handler()
 rethook_free():
   set rh-&gt;handler = NULL;
 return from unreigster_fprobe;
                                   call fp-&gt;exit_handler() &lt;- (*)
------

(*) At this point, the exit handler is called after returning from
unregister_fprobe().

This fixes it as following;
------
 CPU1                              CPU2
 call unregister_fprobe()
 ...
 rethook_stop():
   set rh-&gt;handler = NULL;
                                   __fprobe_handler()
                                   rethook_hook() on probed function
 unregister_ftrace_function()
                                   return from probed function
                                   rethook hooks
                                   find rh-&gt;handler == NULL
                                   return from rethook
 rethook_free()
 return from unreigster_fprobe;
------

Link: https://lore.kernel.org/all/168873859949.156157.13039240432299335849.stgit@devnote2/

Fixes: 5f81018753df ("fprobe: Release rethook after the ftrace_ops is unregistered")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Reviewed-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 195b9cb5b288fec1c871ef89f78cc9a7461aad3a upstream.

Ensure running fprobe_exit_handler() has finished before
calling rethook_free() in the unregister_fprobe() so that caller can free
the fprobe right after unregister_fprobe().

unregister_fprobe() ensured that all running fprobe_entry/exit_handler()
have finished by calling unregister_ftrace_function() which synchronizes
RCU. But commit 5f81018753df ("fprobe: Release rethook after the ftrace_ops
is unregistered") changed to call rethook_free() after
unregister_ftrace_function(). So call rethook_stop() to make rethook
disabled before unregister_ftrace_function() and ensure it again.

Here is the possible code flow that can call the exit handler after
unregister_fprobe().

------
 CPU1                              CPU2
 call unregister_fprobe(fp)
 ...
                                   __fprobe_handler()
                                   rethook_hook() on probed function
 unregister_ftrace_function()
                                   return from probed function
                                   rethook hooks
                                   find rh-&gt;handler == fprobe_exit_handler
                                   call fprobe_exit_handler()
 rethook_free():
   set rh-&gt;handler = NULL;
 return from unreigster_fprobe;
                                   call fp-&gt;exit_handler() &lt;- (*)
------

(*) At this point, the exit handler is called after returning from
unregister_fprobe().

This fixes it as following;
------
 CPU1                              CPU2
 call unregister_fprobe()
 ...
 rethook_stop():
   set rh-&gt;handler = NULL;
                                   __fprobe_handler()
                                   rethook_hook() on probed function
 unregister_ftrace_function()
                                   return from probed function
                                   rethook hooks
                                   find rh-&gt;handler == NULL
                                   return from rethook
 rethook_free()
 return from unreigster_fprobe;
------

Link: https://lore.kernel.org/all/168873859949.156157.13039240432299335849.stgit@devnote2/

Fixes: 5f81018753df ("fprobe: Release rethook after the ftrace_ops is unregistered")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Reviewed-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "8250: add support for ASIX devices with a FIFO bug"</title>
<updated>2023-07-23T11:54:08+00:00</updated>
<author>
<name>Jiaqing Zhao</name>
<email>jiaqing.zhao@linux.intel.com</email>
</author>
<published>2023-06-19T15:57:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ed60e0031cbea6e225dc9df84c3154b86958801b'/>
<id>ed60e0031cbea6e225dc9df84c3154b86958801b</id>
<content type='text'>
commit a82d62f708545d22859584e0e0620da8e3759bbc upstream.

This reverts commit eb26dfe8aa7eeb5a5aa0b7574550125f8aa4c3b3.

Commit eb26dfe8aa7e ("8250: add support for ASIX devices with a FIFO
bug") merged on Jul 13, 2012 adds a quirk for PCI_VENDOR_ID_ASIX
(0x9710). But that ID is the same as PCI_VENDOR_ID_NETMOS defined in
1f8b061050c7 ("[PATCH] Netmos parallel/serial/combo support") merged
on Mar 28, 2005. In pci_serial_quirks array, the NetMos entry always
takes precedence over the ASIX entry even since it was initially
merged, code in that commit is always unreachable.

In my tests, adding the FIFO workaround to pci_netmos_init() makes no
difference, and the vendor driver also does not have such workaround.
Given that the code was never used for over a decade, it's safe to
revert it.

Also, the real PCI_VENDOR_ID_ASIX should be 0x125b, which is used on
their newer AX99100 PCIe serial controllers released on 2016. The FIFO
workaround should not be intended for these newer controllers, and it
was never implemented in vendor driver.

Fixes: eb26dfe8aa7e ("8250: add support for ASIX devices with a FIFO bug")
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Jiaqing Zhao &lt;jiaqing.zhao@linux.intel.com&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20230619155743.827859-1-jiaqing.zhao@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a82d62f708545d22859584e0e0620da8e3759bbc upstream.

This reverts commit eb26dfe8aa7eeb5a5aa0b7574550125f8aa4c3b3.

Commit eb26dfe8aa7e ("8250: add support for ASIX devices with a FIFO
bug") merged on Jul 13, 2012 adds a quirk for PCI_VENDOR_ID_ASIX
(0x9710). But that ID is the same as PCI_VENDOR_ID_NETMOS defined in
1f8b061050c7 ("[PATCH] Netmos parallel/serial/combo support") merged
on Mar 28, 2005. In pci_serial_quirks array, the NetMos entry always
takes precedence over the ASIX entry even since it was initially
merged, code in that commit is always unreachable.

In my tests, adding the FIFO workaround to pci_netmos_init() makes no
difference, and the vendor driver also does not have such workaround.
Given that the code was never used for over a decade, it's safe to
revert it.

Also, the real PCI_VENDOR_ID_ASIX should be 0x125b, which is used on
their newer AX99100 PCIe serial controllers released on 2016. The FIFO
workaround should not be intended for these newer controllers, and it
was never implemented in vendor driver.

Fixes: eb26dfe8aa7e ("8250: add support for ASIX devices with a FIFO bug")
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Jiaqing Zhao &lt;jiaqing.zhao@linux.intel.com&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20230619155743.827859-1-jiaqing.zhao@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kasan: use internal prototypes matching gcc-13 builtins</title>
<updated>2023-07-23T11:53:54+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2023-05-09T14:57:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=29851fd1955860dda918b0b67342c4c3519d0831'/>
<id>29851fd1955860dda918b0b67342c4c3519d0831</id>
<content type='text'>
commit bb6e04a173f06e51819a4bb512e127dfbc50dcfa upstream.

gcc-13 warns about function definitions for builtin interfaces that have a
different prototype, e.g.:

In file included from kasan_test.c:31:
kasan.h:574:6: error: conflicting types for built-in function '__asan_register_globals'; expected 'void(void *, long int)' [-Werror=builtin-declaration-mismatch]
  574 | void __asan_register_globals(struct kasan_global *globals, size_t size);
kasan.h:577:6: error: conflicting types for built-in function '__asan_alloca_poison'; expected 'void(void *, long int)' [-Werror=builtin-declaration-mismatch]
  577 | void __asan_alloca_poison(unsigned long addr, size_t size);
kasan.h:580:6: error: conflicting types for built-in function '__asan_load1'; expected 'void(void *)' [-Werror=builtin-declaration-mismatch]
  580 | void __asan_load1(unsigned long addr);
kasan.h:581:6: error: conflicting types for built-in function '__asan_store1'; expected 'void(void *)' [-Werror=builtin-declaration-mismatch]
  581 | void __asan_store1(unsigned long addr);
kasan.h:643:6: error: conflicting types for built-in function '__hwasan_tag_memory'; expected 'void(void *, unsigned char,  long int)' [-Werror=builtin-declaration-mismatch]
  643 | void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size);

The two problems are:

 - Addresses are passes as 'unsigned long' in the kernel, but gcc-13
   expects a 'void *'.

 - sizes meant to use a signed ssize_t rather than size_t.

Change all the prototypes to match these.  Using 'void *' consistently for
addresses gets rid of a couple of type casts, so push that down to the
leaf functions where possible.

This now passes all randconfig builds on arm, arm64 and x86, but I have
not tested it on the other architectures that support kasan, since they
tend to fail randconfig builds in other ways.  This might fail if any of
the 32-bit architectures expect a 'long' instead of 'int' for the size
argument.

The __asan_allocas_unpoison() function prototype is somewhat weird, since
it uses a pointer for 'stack_top' and an size_t for 'stack_bottom'.  This
looks like it is meant to be 'addr' and 'size' like the others, but the
implementation clearly treats them as 'top' and 'bottom'.

Link: https://lkml.kernel.org/r/20230509145735.9263-2-arnd@kernel.org
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Andrey Konovalov &lt;andreyknvl@gmail.com&gt;
Cc: Andrey Ryabinin &lt;ryabinin.a.a@gmail.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Marco Elver &lt;elver@google.com&gt;
Cc: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit bb6e04a173f06e51819a4bb512e127dfbc50dcfa upstream.

gcc-13 warns about function definitions for builtin interfaces that have a
different prototype, e.g.:

In file included from kasan_test.c:31:
kasan.h:574:6: error: conflicting types for built-in function '__asan_register_globals'; expected 'void(void *, long int)' [-Werror=builtin-declaration-mismatch]
  574 | void __asan_register_globals(struct kasan_global *globals, size_t size);
kasan.h:577:6: error: conflicting types for built-in function '__asan_alloca_poison'; expected 'void(void *, long int)' [-Werror=builtin-declaration-mismatch]
  577 | void __asan_alloca_poison(unsigned long addr, size_t size);
kasan.h:580:6: error: conflicting types for built-in function '__asan_load1'; expected 'void(void *)' [-Werror=builtin-declaration-mismatch]
  580 | void __asan_load1(unsigned long addr);
kasan.h:581:6: error: conflicting types for built-in function '__asan_store1'; expected 'void(void *)' [-Werror=builtin-declaration-mismatch]
  581 | void __asan_store1(unsigned long addr);
kasan.h:643:6: error: conflicting types for built-in function '__hwasan_tag_memory'; expected 'void(void *, unsigned char,  long int)' [-Werror=builtin-declaration-mismatch]
  643 | void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size);

The two problems are:

 - Addresses are passes as 'unsigned long' in the kernel, but gcc-13
   expects a 'void *'.

 - sizes meant to use a signed ssize_t rather than size_t.

Change all the prototypes to match these.  Using 'void *' consistently for
addresses gets rid of a couple of type casts, so push that down to the
leaf functions where possible.

This now passes all randconfig builds on arm, arm64 and x86, but I have
not tested it on the other architectures that support kasan, since they
tend to fail randconfig builds in other ways.  This might fail if any of
the 32-bit architectures expect a 'long' instead of 'int' for the size
argument.

The __asan_allocas_unpoison() function prototype is somewhat weird, since
it uses a pointer for 'stack_top' and an size_t for 'stack_bottom'.  This
looks like it is meant to be 'addr' and 'size' like the others, but the
implementation clearly treats them as 'top' and 'bottom'.

Link: https://lkml.kernel.org/r/20230509145735.9263-2-arnd@kernel.org
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Andrey Konovalov &lt;andreyknvl@gmail.com&gt;
Cc: Andrey Ryabinin &lt;ryabinin.a.a@gmail.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Marco Elver &lt;elver@google.com&gt;
Cc: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nvme: fix the NVME_ID_NS_NVM_STS_MASK definition</title>
<updated>2023-07-23T11:53:45+00:00</updated>
<author>
<name>Ankit Kumar</name>
<email>ankit.kumar@samsung.com</email>
</author>
<published>2023-06-23T12:38:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5647f239a7c00f53b4d6a3300f57f029ea48660c'/>
<id>5647f239a7c00f53b4d6a3300f57f029ea48660c</id>
<content type='text'>
[ Upstream commit b938e6603660652dc3db66d3c915fbfed3bce21d ]

As per NVMe command set specification 1.0c Storage tag size is 7 bits.

Fixes: 4020aad85c67 ("nvme: add support for enhanced metadata")
Signed-off-by: Ankit Kumar &lt;ankit.kumar@samsung.com&gt;
Reviewed-by: Kanchan Joshi &lt;joshi.k@samsung.com&gt;
Signed-off-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit b938e6603660652dc3db66d3c915fbfed3bce21d ]

As per NVMe command set specification 1.0c Storage tag size is 7 bits.

Fixes: 4020aad85c67 ("nvme: add support for enhanced metadata")
Signed-off-by: Ankit Kumar &lt;ankit.kumar@samsung.com&gt;
Reviewed-by: Kanchan Joshi &lt;joshi.k@samsung.com&gt;
Signed-off-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>s390/ism: Fix and simplify add()/remove() callback handling</title>
<updated>2023-07-23T11:53:42+00:00</updated>
<author>
<name>Niklas Schnelle</name>
<email>schnelle@linux.ibm.com</email>
</author>
<published>2023-07-07T10:56:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fdeb916f172e26dfedd068f884a1a2ef2eb8faea'/>
<id>fdeb916f172e26dfedd068f884a1a2ef2eb8faea</id>
<content type='text'>
[ Upstream commit 76631ffa2fd2d45bae5ad717eef716b94144e0e7 ]

Previously the clients_lock was protecting the clients array against
concurrent addition/removal of clients but was also accessed from IRQ
context. This meant that it had to be a spinlock and that the add() and
remove() callbacks in which clients need to do allocation and take
mutexes can't be called under the clients_lock. To work around this these
callbacks were moved to workqueues. This not only introduced significant
complexity but is also subtly broken in at least one way.

In ism_dev_init() and ism_dev_exit() clients[i]-&gt;tgt_ism is used to
communicate the added/removed ISM device to the work function. While
write access to client[i]-&gt;tgt_ism is protected by the clients_lock and
the code waits that there is no pending add/remove work before and after
setting clients[i]-&gt;tgt_ism this is not enough. The problem is that the
wait happens based on per ISM device counters. Thus a concurrent
ism_dev_init()/ism_dev_exit() for a different ISM device may overwrite
a clients[i]-&gt;tgt_ism between unlocking the clients_lock and the
subsequent wait for the work to finnish.

Thankfully with the clients_lock no longer held in IRQ context it can be
turned into a mutex which can be held during the calls to add()/remove()
completely removing the need for the workqueues and the associated
broken housekeeping including the per ISM device counters and the
clients[i]-&gt;tgt_ism.

Fixes: 89e7d2ba61b7 ("net/ism: Add new API for client registration")
Signed-off-by: Niklas Schnelle &lt;schnelle@linux.ibm.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 76631ffa2fd2d45bae5ad717eef716b94144e0e7 ]

Previously the clients_lock was protecting the clients array against
concurrent addition/removal of clients but was also accessed from IRQ
context. This meant that it had to be a spinlock and that the add() and
remove() callbacks in which clients need to do allocation and take
mutexes can't be called under the clients_lock. To work around this these
callbacks were moved to workqueues. This not only introduced significant
complexity but is also subtly broken in at least one way.

In ism_dev_init() and ism_dev_exit() clients[i]-&gt;tgt_ism is used to
communicate the added/removed ISM device to the work function. While
write access to client[i]-&gt;tgt_ism is protected by the clients_lock and
the code waits that there is no pending add/remove work before and after
setting clients[i]-&gt;tgt_ism this is not enough. The problem is that the
wait happens based on per ISM device counters. Thus a concurrent
ism_dev_init()/ism_dev_exit() for a different ISM device may overwrite
a clients[i]-&gt;tgt_ism between unlocking the clients_lock and the
subsequent wait for the work to finnish.

Thankfully with the clients_lock no longer held in IRQ context it can be
turned into a mutex which can be held during the calls to add()/remove()
completely removing the need for the workqueues and the associated
broken housekeeping including the per ISM device counters and the
clients[i]-&gt;tgt_ism.

Fixes: 89e7d2ba61b7 ("net/ism: Add new API for client registration")
Signed-off-by: Niklas Schnelle &lt;schnelle@linux.ibm.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
