| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: fix deadlock in remain-on-channel
mt76_remain_on_channel() and mt76_roc_complete() call mt76_set_channel()
while already holding dev->mutex. Since mt76_set_channel() also acquires
dev->mutex, this results in a deadlock.
Use __mt76_set_channel() instead of mt76_set_channel().
Add cancel_delayed_work_sync() for mac_work before acquiring the mutex
in mt76_remain_on_channel() to prevent a secondary deadlock with the
mac_work workqueue. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: usbhid: fix deadlock in hid_post_reset()
You can build a USB device that includes a HID component
and a storage or UAS component. The components can be reset
only together. That means that hid_pre_reset() and hid_post_reset()
are in the block IO error handling. Hence no memory allocation
used in them may do block IO because the IO can deadlock
on the mutex held while resetting a device and calling the
interface drivers.
Use GFP_NOIO for all allocations in them. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/shstk: Prevent deadlock during shstk sigreturn
During sigreturn the shadow stack signal frame is popped. The kernel does
this by reading the shadow stack using normal read accesses. When it can't
assume the memory is shadow stack, it takes extra steps to makes sure it is
reading actual shadow stack memory and not other normal readable memory. It
does this by holding the mmap read lock while doing the access and checking
the flags of the VMA.
Unfortunately that is not safe. If the read of the shadow stack sigframe
hits a page fault, the fault handler will try to recursively grab another
mmap read lock. This normally works ok, but if a writer on another CPU is
also waiting, the second read lock could fail and cause a deadlock.
Fix this by not holding mmap lock during the read access to userspace.
Instead use mmap_lock_speculate_...() to watch for changes between dropping
mmap lock and the userspace access. Retry if anything grabbed an mmap write
lock in between and could have changed the VMA.
These mmap_lock_speculate_...() helpers use mm::mm_lock_seq, which is only
available when PER_VMA_LOCK is configured. So make X86_USER_SHADOW_STACK
depend on it. On x86, PER_VMA_LOCK is a default configuration for SMP
kernels. So drop support for the other configs under the assumption that
the !SMP shadow stack user base does not exist.
Currently there is a check that skips the lookup work when the SSP can be
assumed to be on a shadow stack. While reorganizing the function, remove
the optimization to make the tricky code flows more common, such that
issues like this cannot escape detection for so long. |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: fsl_xcvr: Revert fix missing lock in fsl_xcvr_mode_put()
This reverts commit f51424872760 ("ASoC: fsl_xcvr: fix missing lock in fsl_xcvr_mode_put()").
The original patch attempted to acquire the card->controls_rwsem lock in
fsl_xcvr_mode_put(). However, this function is called from the upper ALSA
core function snd_ctl_elem_write(), which already holds the write lock on
controls_rwsem for the whole put operation. So there is no need to simply
hold the lock for fsl_xcvr_activate_ctl() again.
Acquiring the read lock while holding the write lock in the same thread
results in a deadlock and a hung task, as reported by Alexander Stein. |
| In the Linux kernel, the following vulnerability has been resolved:
spi: spidev: fix lock inversion between spi_lock and buf_lock
The spidev driver previously used two mutexes, spi_lock and buf_lock,
but acquired them in different orders depending on the code path:
write()/read(): buf_lock -> spi_lock
ioctl(): spi_lock -> buf_lock
This AB-BA locking pattern triggers lockdep warnings and can
cause real deadlocks:
WARNING: possible circular locking dependency detected
spidev_ioctl() -> mutex_lock(&spidev->buf_lock)
spidev_sync_write() -> mutex_lock(&spidev->spi_lock)
*** DEADLOCK ***
The issue is reproducible with a simple userspace program that
performs write() and SPI_IOC_WR_MAX_SPEED_HZ ioctl() calls from
separate threads on the same spidev file descriptor.
Fix this by simplifying the locking model and removing the lock
inversion entirely. spidev_sync() no longer performs any locking,
and all callers serialize access using spi_lock.
buf_lock is removed since its functionality is fully covered by
spi_lock, eliminating the possibility of lock ordering issues.
This removes the lock inversion and prevents deadlocks without
changing userspace ABI or behaviour. |
| In the Linux kernel, the following vulnerability has been resolved:
serial: 8250: Fix TX deadlock when using DMA
`dmaengine_terminate_async` does not guarantee that the
`__dma_tx_complete` callback will run. The callback is currently the
only place where `dma->tx_running` gets cleared. If the transaction is
canceled and the callback never runs, then `dma->tx_running` will never
get cleared and we will never schedule new TX DMA transactions again.
This change makes it so we clear `dma->tx_running` after we terminate
the DMA transaction. This is "safe" because `serial8250_tx_dma_flush`
is holding the UART port lock. The first thing the callback does is also
grab the UART port lock, so access to `dma->tx_running` is serialized. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: Fix deadlock between devlink lock and esw->wq
esw->work_queue executes esw_functions_changed_event_handler ->
esw_vfs_changed_event_handler and acquires the devlink lock.
.eswitch_mode_set (acquires devlink lock in devlink_nl_pre_doit) ->
mlx5_devlink_eswitch_mode_set -> mlx5_eswitch_disable_locked ->
mlx5_eswitch_event_handler_unregister -> flush_workqueue deadlocks
when esw_vfs_changed_event_handler executes.
Fix that by no longer flushing the work to avoid the deadlock, and using
a generation counter to keep track of work relevance. This avoids an old
handler manipulating an esw that has undergone one or more mode changes:
- the counter is incremented in mlx5_eswitch_event_handler_unregister.
- the counter is read and passed to the ephemeral mlx5_host_work struct.
- the work handler takes the devlink lock and bails out if the current
generation is different than the one it was scheduled to operate on.
- mlx5_eswitch_cleanup does the final draining before destroying the wq.
No longer flushing the workqueue has the side effect of maybe no longer
cancelling pending vport_change_handler work items, but that's ok since
those are disabled elsewhere:
- mlx5_eswitch_disable_locked disables the vport eq notifier.
- mlx5_esw_vport_disable disarms the HW EQ notification and marks
vport->enabled under state_lock to false to prevent pending vport
handler from doing anything.
- mlx5_eswitch_cleanup destroys the workqueue and makes sure all events
are disabled/finished. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix mismatched unlock for DMUB HW lock in HWSS fast path
[Why]
The evaluation for whether we need to use the DMUB HW lock isn't the
same as whether we need to unlock which results in a hang when the
fast path is used for ASIC without FAMS support.
[How]
Store a flag that indicates whether we should use the lock and use
that same flag to specify whether unlocking is needed. |
| In the Linux kernel, the following vulnerability has been resolved:
Revert "PCI/IOV: Add PCI rescan-remove locking when enabling/disabling SR-IOV"
This reverts commit 05703271c3cd ("PCI/IOV: Add PCI rescan-remove locking
when enabling/disabling SR-IOV"), which causes a deadlock by recursively
taking pci_rescan_remove_lock when sriov_del_vfs() is called as part of
pci_stop_and_remove_bus_device(). For example with the following sequence
of commands:
$ echo <NUM> > /sys/bus/pci/devices/<pf>/sriov_numvfs
$ echo 1 > /sys/bus/pci/devices/<pf>/remove
A trimmed trace of the deadlock on a mlx5 device is as below:
zsh/5715 is trying to acquire lock:
000002597926ef50 (pci_rescan_remove_lock){+.+.}-{3:3}, at: sriov_disable+0x34/0x140
but task is already holding lock:
000002597926ef50 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_stop_and_remove_bus_device_locked+0x24/0x80
...
Call Trace:
[<00000259778c4f90>] dump_stack_lvl+0xc0/0x110
[<00000259779c844e>] print_deadlock_bug+0x31e/0x330
[<00000259779c1908>] __lock_acquire+0x16c8/0x32f0
[<00000259779bffac>] lock_acquire+0x14c/0x350
[<00000259789643a6>] __mutex_lock_common+0xe6/0x1520
[<000002597896413c>] mutex_lock_nested+0x3c/0x50
[<00000259784a07e4>] sriov_disable+0x34/0x140
[<00000258f7d6dd80>] mlx5_sriov_disable+0x50/0x80 [mlx5_core]
[<00000258f7d5745e>] remove_one+0x5e/0xf0 [mlx5_core]
[<00000259784857fc>] pci_device_remove+0x3c/0xa0
[<000002597851012e>] device_release_driver_internal+0x18e/0x280
[<000002597847ae22>] pci_stop_bus_device+0x82/0xa0
[<000002597847afce>] pci_stop_and_remove_bus_device_locked+0x5e/0x80
[<00000259784972c2>] remove_store+0x72/0x90
[<0000025977e6661a>] kernfs_fop_write_iter+0x15a/0x200
[<0000025977d7241c>] vfs_write+0x24c/0x300
[<0000025977d72696>] ksys_write+0x86/0x110
[<000002597895b61c>] __do_syscall+0x14c/0x400
[<000002597896e0ee>] system_call+0x6e/0x90
This alone is not a complete fix as it restores the issue the cited commit
tried to solve. A new fix will be provided as a follow on. |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix RELEASE_LOCKOWNER
The test on so_count in nfsd4_release_lockowner() is nonsense and
harmful. Revert to using check_for_locks(), changing that to not sleep.
First: harmful.
As is documented in the kdoc comment for nfsd4_release_lockowner(), the
test on so_count can transiently return a false positive resulting in a
return of NFS4ERR_LOCKS_HELD when in fact no locks are held. This is
clearly a protocol violation and with the Linux NFS client it can cause
incorrect behaviour.
If RELEASE_LOCKOWNER is sent while some other thread is still
processing a LOCK request which failed because, at the time that request
was received, the given owner held a conflicting lock, then the nfsd
thread processing that LOCK request can hold a reference (conflock) to
the lock owner that causes nfsd4_release_lockowner() to return an
incorrect error.
The Linux NFS client ignores that NFS4ERR_LOCKS_HELD error because it
never sends NFS4_RELEASE_LOCKOWNER without first releasing any locks, so
it knows that the error is impossible. It assumes the lock owner was in
fact released so it feels free to use the same lock owner identifier in
some later locking request.
When it does reuse a lock owner identifier for which a previous RELEASE
failed, it will naturally use a lock_seqid of zero. However the server,
which didn't release the lock owner, will expect a larger lock_seqid and
so will respond with NFS4ERR_BAD_SEQID.
So clearly it is harmful to allow a false positive, which testing
so_count allows.
The test is nonsense because ... well... it doesn't mean anything.
so_count is the sum of three different counts.
1/ the set of states listed on so_stateids
2/ the set of active vfs locks owned by any of those states
3/ various transient counts such as for conflicting locks.
When it is tested against '2' it is clear that one of these is the
transient reference obtained by find_lockowner_str_locked(). It is not
clear what the other one is expected to be.
In practice, the count is often 2 because there is precisely one state
on so_stateids. If there were more, this would fail.
In my testing I see two circumstances when RELEASE_LOCKOWNER is called.
In one case, CLOSE is called before RELEASE_LOCKOWNER. That results in
all the lock states being removed, and so the lockowner being discarded
(it is removed when there are no more references which usually happens
when the lock state is discarded). When nfsd4_release_lockowner() finds
that the lock owner doesn't exist, it returns success.
The other case shows an so_count of '2' and precisely one state listed
in so_stateid. It appears that the Linux client uses a separate lock
owner for each file resulting in one lock state per lock owner, so this
test on '2' is safe. For another client it might not be safe.
So this patch changes check_for_locks() to use the (newish)
find_any_file_locked() so that it doesn't take a reference on the
nfs4_file and so never calls nfsd_file_put(), and so never sleeps. With
this check is it safe to restore the use of check_for_locks() rather
than testing so_count against the mysterious '2'. |
| In the Linux kernel, the following vulnerability has been resolved:
bus: mhi: host: pci_generic: Use pci_try_reset_function() to avoid deadlock
There are multiple places from where the recovery work gets scheduled
asynchronously. Also, there are multiple places where the caller waits
synchronously for the recovery to be completed. One such place is during
the PM shutdown() callback.
If the device is not alive during recovery_work, it will try to reset the
device using pci_reset_function(). This function internally will take the
device_lock() first before resetting the device. By this time, if the lock
has already been acquired, then recovery_work will get stalled while
waiting for the lock. And if the lock was already acquired by the caller
which waits for the recovery_work to be completed, it will lead to
deadlock.
This is what happened on the X1E80100 CRD device when the device died
before shutdown() callback. Driver core calls the driver's shutdown()
callback while holding the device_lock() leading to deadlock.
And this deadlock scenario can occur on other paths as well, like during
the PM suspend() callback, where the driver core would hold the
device_lock() before calling driver's suspend() callback. And if the
recovery_work was already started, it could lead to deadlock. This is also
observed on the X1E80100 CRD.
So to fix both issues, use pci_try_reset_function() in recovery_work. This
function first checks for the availability of the device_lock() before
trying to reset the device. If the lock is available, it will acquire it
and reset the device. Otherwise, it will return -EAGAIN. If that happens,
recovery_work will fail with the error message "Recovery failed" as not
much could be done. |
| Spring MVC and WebFlux applications are vulnerable to stream corruption when using Server-Sent Events (SSE). This issue affects Spring Foundation: from 7.0.0 through 7.0.5, from 6.2.0 through 6.2.16, from 6.1.0 through 6.1.25, from 5.3.0 through 5.3.46. |
| net/ipv4/udp.c in the Linux kernel before 2.6.29.1 performs an unlocking step in certain incorrect circumstances, which allows local users to cause a denial of service (panic) by reading zero bytes from the /proc/net/udp file and unspecified other files, related to the "udp seq_file infrastructure." |
| The inode double locking code in fs/ocfs2/file.c in the Linux kernel 2.6.30 before 2.6.30-rc3, 2.6.27 before 2.6.27.24, 2.6.29 before 2.6.29.4, and possibly other versions down to 2.6.19 allows local users to cause a denial of service (prevention of file creation and removal) via a series of splice system calls that trigger a deadlock between the generic_file_splice_write, splice_from_pipe, and ocfs2_file_splice_write functions. |
| The Solaris pollset feature in the Event Port backend in poll/unix/port.c in the Apache Portable Runtime (APR) library before 1.3.9, as used in the Apache HTTP Server before 2.2.14 and other products, does not properly handle errors, which allows remote attackers to cause a denial of service (daemon hang) via unspecified HTTP requests, related to the prefork and event MPMs. |
| The nlmclnt_mark_reclaim in clntlock.c in NFS lockd in Linux kernel before 2.6.16 allows remote attackers to cause a denial of service (process crash) and deny access to NFS exports via unspecified vectors that trigger a kernel oops (null dereference) and a deadlock. |
| The kernel in Red Hat Enterprise Linux 3, when running on SMP systems, allows local users to cause a denial of service (deadlock) by running the shmat function on an shm at the same time that shmctl is removing that shm (IPC_RMID), which prevents a spinlock from being unlocked. |
| fs/splice.c in the splice subsystem in the Linux kernel before 2.6.22.2 does not properly handle a failure of the add_to_page_cache_lru function, and subsequently attempts to unlock a page that was not locked, which allows local users to cause a denial of service (kernel BUG and system crash), as demonstrated by the fio I/O tool. |
| The inotify_read function in the Linux kernel 2.6.27 to 2.6.27.13, 2.6.28 to 2.6.28.2, and 2.6.29-rc3 allows local users to cause a denial of service (OOPS) via a read with an invalid address to an inotify instance, which causes the device's event list mutex to be unlocked twice and prevents proper synchronization of a data structure for the inotify instance. |
| The ptrace_start function in kernel/ptrace.c in the Linux kernel 2.6.18 does not properly handle simultaneous execution of the do_coredump function, which allows local users to cause a denial of service (deadlock) via vectors involving the ptrace system call and a coredumping thread. |
