In the Linux kernel, the following vulnerability has been resolved:
futex: Clear stale exiting pointer in futex_lock_pi() retry path
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.
In the Linux kernel, the following vulnerability has been resolved:
xfs: scrub: unlock dquot before early return in quota scrub
xchk_quota_item can return early after calling xchk_fblock_process_error.
When that helper returns false, the function returned immediately without
dropping dq->q_qlock, which can leave the dquot lock held and risk lock
leaks or deadlocks in later quota operations.
Fix this by unlocking dq->q_qlock before the early return.
In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix trace_marker copy link list updates
When the "copy_trace_marker" option is enabled for an instance, anything
written into /sys/kernel/tracing/trace_marker is also copied into that
instances buffer. When the option is set, that instance's trace_array
descriptor is added to the marker_copies link list. This list is protected
by RCU, as all iterations uses an RCU protected list traversal.
When the instance is deleted, all the flags that were enabled are cleared.
This also clears the copy_trace_marker flag and removes the trace_array
descriptor from the list.
The issue is after the flags are called, a direct call to
update_marker_trace() is performed to clear the flag. This function
returns true if the state of the flag changed and false otherwise. If it
returns true here, synchronize_rcu() is called to make sure all readers
see that its removed from the list.
But since the flag was already cleared, the state does not change and the
synchronization is never called, leaving a possible UAF bug.
Move the clearing of all flags below the updating of the copy_trace_marker
option which then makes sure the synchronization is performed.
Also use the flag for checking the state in update_marker_trace() instead
of looking at if the list is empty.
In the Linux kernel, the following vulnerability has been resolved:
x86/platform/uv: Handle deconfigured sockets
When a socket is deconfigured, it's mapped to SOCK_EMPTY (0xffff). This causes
a panic while allocating UV hub info structures.
Fix this by using NUMA_NO_NODE, allowing UV hub info structures to be
allocated on valid nodes.
In the Linux kernel, the following vulnerability has been resolved:
crash_dump: don't log dm-crypt key bytes in read_key_from_user_keying
When debug logging is enabled, read_key_from_user_keying() logs the first
8 bytes of the key payload and partially exposes the dm-crypt key. Stop
logging any key bytes.
In the Linux kernel, the following vulnerability has been resolved:
firmware: arm_scmi: Fix NULL dereference on notify error path
Since commit b5daf93b809d1 ("firmware: arm_scmi: Avoid notifier
registration for unsupported events") the call chains leading to the helper
__scmi_event_handler_get_ops expect an ERR_PTR to be returned on failure to
get an handler for the requested event key, while the current helper can
still return a NULL when no handler could be found or created.
Fix by forcing an ERR_PTR return value when the handler reference is NULL.
In the Linux kernel, the following vulnerability has been resolved:
NFC: nxp-nci: allow GPIOs to sleep
Allow the firmware and enable GPIOs to sleep.
This fixes a `WARN_ON' and allows the driver to operate GPIOs which are
connected to I2C GPIO expanders.
-- >8 --
kernel: WARNING: CPU: 3 PID: 2636 at drivers/gpio/gpiolib.c:3880 gpiod_set_value+0x88/0x98
-- >8 --
In the Linux kernel, the following vulnerability has been resolved:
drm/xe: Fix missing runtime PM reference in ccs_mode_store
ccs_mode_store() calls xe_gt_reset() which internally invokes
xe_pm_runtime_get_noresume(). That function requires the caller
to already hold an outer runtime PM reference and warns if none
is held:
[46.891177] xe 0000:03:00.0: [drm] Missing outer runtime PM protection
[46.891178] WARNING: drivers/gpu/drm/xe/xe_pm.c:885 at
xe_pm_runtime_get_noresume+0x8b/0xc0
Fix this by protecting xe_gt_reset() with the scope-based
guard(xe_pm_runtime)(xe), which is the preferred form when
the reference lifetime matches a single scope.
v2:
- Use scope-based guard(xe_pm_runtime)(xe) (Shuicheng)
- Update commit message accordingly
(cherry picked from commit 7937ea733f79b3f25e802a0c8360bf7423856f36)
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: cancel pmsr_free_wk in cfg80211_pmsr_wdev_down
When the nl80211 socket that originated a PMSR request is
closed, cfg80211_release_pmsr() sets the request's nl_portid
to zero and schedules pmsr_free_wk to process the abort
asynchronously. If the interface is concurrently torn down
before that work runs, cfg80211_pmsr_wdev_down() calls
cfg80211_pmsr_process_abort() directly. However, the already-
scheduled pmsr_free_wk work item remains pending and may run
after the interface has been removed from the driver. This
could cause the driver's abort_pmsr callback to operate on a
torn-down interface, leading to undefined behavior and
potential crashes.
Cancel pmsr_free_wk synchronously in cfg80211_pmsr_wdev_down()
before calling cfg80211_pmsr_process_abort(). This ensures any
pending or in-progress work is drained before interface teardown
proceeds, preventing the work from invoking the driver abort
callback after the interface is gone.