| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid potential deadlock
Using f2fs_trylock_op() in f2fs_write_compressed_pages() to avoid potential
deadlock like we did in f2fs_write_single_data_page(). |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: Fix deadlocks with kctl removals at disconnection
In snd_card_disconnect(), we set card->shutdown flag at the beginning,
call callbacks and do sync for card->power_ref_sleep waiters at the
end. The callback may delete a kctl element, and this can lead to a
deadlock when the device was in the suspended state. Namely:
* A process waits for the power up at snd_power_ref_and_wait() in
snd_ctl_info() or read/write() inside card->controls_rwsem.
* The system gets disconnected meanwhile, and the driver tries to
delete a kctl via snd_ctl_remove*(); it tries to take
card->controls_rwsem again, but this is already locked by the
above. Since the sleeper isn't woken up, this deadlocks.
An easy fix is to wake up sleepers before processing the driver
disconnect callbacks but right after setting the card->shutdown flag.
Then all sleepers will abort immediately, and the code flows again.
So, basically this patch moves the wait_event() call at the right
timing. While we're at it, just to be sure, call wait_event_all()
instead of wait_event(), although we don't use exclusive events on
this queue for now. |
| In the Linux kernel, the following vulnerability has been resolved:
md/raid5: fix deadlock that raid5d() wait for itself to clear MD_SB_CHANGE_PENDING
Xiao reported that lvm2 test lvconvert-raid-takeover.sh can hang with
small possibility, the root cause is exactly the same as commit
bed9e27baf52 ("Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d"")
However, Dan reported another hang after that, and junxiao investigated
the problem and found out that this is caused by plugged bio can't issue
from raid5d().
Current implementation in raid5d() has a weird dependence:
1) md_check_recovery() from raid5d() must hold 'reconfig_mutex' to clear
MD_SB_CHANGE_PENDING;
2) raid5d() handles IO in a deadloop, until all IO are issued;
3) IO from raid5d() must wait for MD_SB_CHANGE_PENDING to be cleared;
This behaviour is introduce before v2.6, and for consequence, if other
context hold 'reconfig_mutex', and md_check_recovery() can't update
super_block, then raid5d() will waste one cpu 100% by the deadloop, until
'reconfig_mutex' is released.
Refer to the implementation from raid1 and raid10, fix this problem by
skipping issue IO if MD_SB_CHANGE_PENDING is still set after
md_check_recovery(), daemon thread will be woken up when 'reconfig_mutex'
is released. Meanwhile, the hang problem will be fixed as well. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: Revert "scsi: fcoe: Fix potential deadlock on &fip->ctlr_lock"
This reverts commit 1a1975551943f681772720f639ff42fbaa746212.
This commit causes interrupts to be lost for FCoE devices, since it changed
sping locks from "bh" to "irqsave".
Instead, a work queue should be used, and will be addressed in a separate
commit. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: af_bluetooth: Fix deadlock
Attemting to do sock_lock on .recvmsg may cause a deadlock as shown
bellow, so instead of using sock_sock this uses sk_receive_queue.lock
on bt_sock_ioctl to avoid the UAF:
INFO: task kworker/u9:1:121 blocked for more than 30 seconds.
Not tainted 6.7.6-lemon #183
Workqueue: hci0 hci_rx_work
Call Trace:
<TASK>
__schedule+0x37d/0xa00
schedule+0x32/0xe0
__lock_sock+0x68/0xa0
? __pfx_autoremove_wake_function+0x10/0x10
lock_sock_nested+0x43/0x50
l2cap_sock_recv_cb+0x21/0xa0
l2cap_recv_frame+0x55b/0x30a0
? psi_task_switch+0xeb/0x270
? finish_task_switch.isra.0+0x93/0x2a0
hci_rx_work+0x33a/0x3f0
process_one_work+0x13a/0x2f0
worker_thread+0x2f0/0x410
? __pfx_worker_thread+0x10/0x10
kthread+0xe0/0x110
? __pfx_kthread+0x10/0x10
ret_from_fork+0x2c/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK> |
| In the Linux kernel, the following vulnerability has been resolved:
PCI/ASPM: Fix deadlock when enabling ASPM
A last minute revert in 6.7-final introduced a potential deadlock when
enabling ASPM during probe of Qualcomm PCIe controllers as reported by
lockdep:
============================================
WARNING: possible recursive locking detected
6.7.0 #40 Not tainted
--------------------------------------------
kworker/u16:5/90 is trying to acquire lock:
ffffacfa78ced000 (pci_bus_sem){++++}-{3:3}, at: pcie_aspm_pm_state_change+0x58/0xdc
but task is already holding lock:
ffffacfa78ced000 (pci_bus_sem){++++}-{3:3}, at: pci_walk_bus+0x34/0xbc
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(pci_bus_sem);
lock(pci_bus_sem);
*** DEADLOCK ***
Call trace:
print_deadlock_bug+0x25c/0x348
__lock_acquire+0x10a4/0x2064
lock_acquire+0x1e8/0x318
down_read+0x60/0x184
pcie_aspm_pm_state_change+0x58/0xdc
pci_set_full_power_state+0xa8/0x114
pci_set_power_state+0xc4/0x120
qcom_pcie_enable_aspm+0x1c/0x3c [pcie_qcom]
pci_walk_bus+0x64/0xbc
qcom_pcie_host_post_init_2_7_0+0x28/0x34 [pcie_qcom]
The deadlock can easily be reproduced on machines like the Lenovo ThinkPad
X13s by adding a delay to increase the race window during asynchronous
probe where another thread can take a write lock.
Add a new pci_set_power_state_locked() and associated helper functions that
can be called with the PCI bus semaphore held to avoid taking the read lock
twice. |
| In the Linux kernel, the following vulnerability has been resolved:
audit: improve robustness of the audit queue handling
If the audit daemon were ever to get stuck in a stopped state the
kernel's kauditd_thread() could get blocked attempting to send audit
records to the userspace audit daemon. With the kernel thread
blocked it is possible that the audit queue could grow unbounded as
certain audit record generating events must be exempt from the queue
limits else the system enter a deadlock state.
This patch resolves this problem by lowering the kernel thread's
socket sending timeout from MAX_SCHEDULE_TIMEOUT to HZ/10 and tweaks
the kauditd_send_queue() function to better manage the various audit
queues when connection problems occur between the kernel and the
audit daemon. With this patch, the backlog may temporarily grow
beyond the defined limits when the audit daemon is stopped and the
system is under heavy audit pressure, but kauditd_thread() will
continue to make progress and drain the queues as it would for other
connection problems. For example, with the audit daemon put into a
stopped state and the system configured to audit every syscall it
was still possible to shutdown the system without a kernel panic,
deadlock, etc.; granted, the system was slow to shutdown but that is
to be expected given the extreme pressure of recording every syscall.
The timeout value of HZ/10 was chosen primarily through
experimentation and this developer's "gut feeling". There is likely
no one perfect value, but as this scenario is limited in scope (root
privileges would be needed to send SIGSTOP to the audit daemon), it
is likely not worth exposing this as a tunable at present. This can
always be done at a later date if it proves necessary. |
| In the Linux kernel, the following vulnerability has been resolved:
s390/qeth: fix deadlock during failing recovery
Commit 0b9902c1fcc5 ("s390/qeth: fix deadlock during recovery") removed
taking discipline_mutex inside qeth_do_reset(), fixing potential
deadlocks. An error path was missed though, that still takes
discipline_mutex and thus has the original deadlock potential.
Intermittent deadlocks were seen when a qeth channel path is configured
offline, causing a race between qeth_do_reset and ccwgroup_remove.
Call qeth_set_offline() directly in the qeth_do_reset() error case and
then a new variant of ccwgroup_set_offline(), without taking
discipline_mutex. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: core: sysfs: Fix hang when device state is set via sysfs
This fixes a regression added with:
commit f0f82e2476f6 ("scsi: core: Fix capacity set to zero after
offlinining device")
The problem is that after iSCSI recovery, iscsid will call into the kernel
to set the dev's state to running, and with that patch we now call
scsi_rescan_device() with the state_mutex held. If the SCSI error handler
thread is just starting to test the device in scsi_send_eh_cmnd() then it's
going to try to grab the state_mutex.
We are then stuck, because when scsi_rescan_device() tries to send its I/O
scsi_queue_rq() calls -> scsi_host_queue_ready() -> scsi_host_in_recovery()
which will return true (the host state is still in recovery) and I/O will
just be requeued. scsi_send_eh_cmnd() will then never be able to grab the
state_mutex to finish error handling.
To prevent the deadlock move the rescan-related code to after we drop the
state_mutex.
This also adds a check for if we are already in the running state. This
prevents extra scans and helps the iscsid case where if the transport class
has already onlined the device during its recovery process then we don't
need userspace to do it again plus possibly block that daemon. |
| In the Linux kernel, the following vulnerability has been resolved:
firmware: qcom: uefisecapp: Fix deadlock in qcuefi_acquire()
If the __qcuefi pointer is not set, then in the original code, we would
hold onto the lock. That means that if we tried to set it later, then
it would cause a deadlock. Drop the lock on the error path. That's
what all the callers are expecting. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/client: fix deadlock in show_meminfo()
There is a real deadlock as well as sleeping in atomic() bug in here, if
the bo put happens to be the last ref, since bo destruction wants to
grab the same spinlock and sleeping locks. Fix that by dropping the ref
using xe_bo_put_deferred(), and moving the final commit outside of the
lock. Dropping the lock around the put is tricky since the bo can go
out of scope and delete itself from the list, making it difficult to
navigate to the next list entry.
(cherry picked from commit 0083b8e6f11d7662283a267d4ce7c966812ffd8a) |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: Fix deadlock during RTC update
There is a deadlock when runtime suspend waits for the flush of RTC work,
and the RTC work calls ufshcd_rpm_get_sync() to wait for runtime resume.
Here is deadlock backtrace:
kworker/0:1 D 4892.876354 10 10971 4859 0x4208060 0x8 10 0 120 670730152367
ptr f0ffff80c2e40000 0 1 0x00000001 0x000000ff 0x000000ff 0x000000ff
<ffffffee5e71ddb0> __switch_to+0x1a8/0x2d4
<ffffffee5e71e604> __schedule+0x684/0xa98
<ffffffee5e71ea60> schedule+0x48/0xc8
<ffffffee5e725f78> schedule_timeout+0x48/0x170
<ffffffee5e71fb74> do_wait_for_common+0x108/0x1b0
<ffffffee5e71efe0> wait_for_completion+0x44/0x60
<ffffffee5d6de968> __flush_work+0x39c/0x424
<ffffffee5d6decc0> __cancel_work_sync+0xd8/0x208
<ffffffee5d6dee2c> cancel_delayed_work_sync+0x14/0x28
<ffffffee5e2551b8> __ufshcd_wl_suspend+0x19c/0x480
<ffffffee5e255fb8> ufshcd_wl_runtime_suspend+0x3c/0x1d4
<ffffffee5dffd80c> scsi_runtime_suspend+0x78/0xc8
<ffffffee5df93580> __rpm_callback+0x94/0x3e0
<ffffffee5df90b0c> rpm_suspend+0x2d4/0x65c
<ffffffee5df91448> __pm_runtime_suspend+0x80/0x114
<ffffffee5dffd95c> scsi_runtime_idle+0x38/0x6c
<ffffffee5df912f4> rpm_idle+0x264/0x338
<ffffffee5df90f14> __pm_runtime_idle+0x80/0x110
<ffffffee5e24ce44> ufshcd_rtc_work+0x128/0x1e4
<ffffffee5d6e3a40> process_one_work+0x26c/0x650
<ffffffee5d6e65c8> worker_thread+0x260/0x3d8
<ffffffee5d6edec8> kthread+0x110/0x134
<ffffffee5d616b18> ret_from_fork+0x10/0x20
Skip updating RTC if RPM state is not RPM_ACTIVE. |
| In the Linux kernel, the following vulnerability has been resolved:
net: wan: fsl_qmc_hdlc: Convert carrier_lock spinlock to a mutex
The carrier_lock spinlock protects the carrier detection. While it is
held, framer_get_status() is called which in turn takes a mutex.
This is not correct and can lead to a deadlock.
A run with PROVE_LOCKING enabled detected the issue:
[ BUG: Invalid wait context ]
...
c204ddbc (&framer->mutex){+.+.}-{3:3}, at: framer_get_status+0x40/0x78
other info that might help us debug this:
context-{4:4}
2 locks held by ifconfig/146:
#0: c0926a38 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x12c/0x664
#1: c2006a40 (&qmc_hdlc->carrier_lock){....}-{2:2}, at: qmc_hdlc_framer_set_carrier+0x30/0x98
Avoid the spinlock usage and convert carrier_lock to a mutex. |
| In the Linux kernel, the following vulnerability has been resolved:
block: fix deadlock between sd_remove & sd_release
Our test report the following hung task:
[ 2538.459400] INFO: task "kworker/0:0":7 blocked for more than 188 seconds.
[ 2538.459427] Call trace:
[ 2538.459430] __switch_to+0x174/0x338
[ 2538.459436] __schedule+0x628/0x9c4
[ 2538.459442] schedule+0x7c/0xe8
[ 2538.459447] schedule_preempt_disabled+0x24/0x40
[ 2538.459453] __mutex_lock+0x3ec/0xf04
[ 2538.459456] __mutex_lock_slowpath+0x14/0x24
[ 2538.459459] mutex_lock+0x30/0xd8
[ 2538.459462] del_gendisk+0xdc/0x350
[ 2538.459466] sd_remove+0x30/0x60
[ 2538.459470] device_release_driver_internal+0x1c4/0x2c4
[ 2538.459474] device_release_driver+0x18/0x28
[ 2538.459478] bus_remove_device+0x15c/0x174
[ 2538.459483] device_del+0x1d0/0x358
[ 2538.459488] __scsi_remove_device+0xa8/0x198
[ 2538.459493] scsi_forget_host+0x50/0x70
[ 2538.459497] scsi_remove_host+0x80/0x180
[ 2538.459502] usb_stor_disconnect+0x68/0xf4
[ 2538.459506] usb_unbind_interface+0xd4/0x280
[ 2538.459510] device_release_driver_internal+0x1c4/0x2c4
[ 2538.459514] device_release_driver+0x18/0x28
[ 2538.459518] bus_remove_device+0x15c/0x174
[ 2538.459523] device_del+0x1d0/0x358
[ 2538.459528] usb_disable_device+0x84/0x194
[ 2538.459532] usb_disconnect+0xec/0x300
[ 2538.459537] hub_event+0xb80/0x1870
[ 2538.459541] process_scheduled_works+0x248/0x4dc
[ 2538.459545] worker_thread+0x244/0x334
[ 2538.459549] kthread+0x114/0x1bc
[ 2538.461001] INFO: task "fsck.":15415 blocked for more than 188 seconds.
[ 2538.461014] Call trace:
[ 2538.461016] __switch_to+0x174/0x338
[ 2538.461021] __schedule+0x628/0x9c4
[ 2538.461025] schedule+0x7c/0xe8
[ 2538.461030] blk_queue_enter+0xc4/0x160
[ 2538.461034] blk_mq_alloc_request+0x120/0x1d4
[ 2538.461037] scsi_execute_cmd+0x7c/0x23c
[ 2538.461040] ioctl_internal_command+0x5c/0x164
[ 2538.461046] scsi_set_medium_removal+0x5c/0xb0
[ 2538.461051] sd_release+0x50/0x94
[ 2538.461054] blkdev_put+0x190/0x28c
[ 2538.461058] blkdev_release+0x28/0x40
[ 2538.461063] __fput+0xf8/0x2a8
[ 2538.461066] __fput_sync+0x28/0x5c
[ 2538.461070] __arm64_sys_close+0x84/0xe8
[ 2538.461073] invoke_syscall+0x58/0x114
[ 2538.461078] el0_svc_common+0xac/0xe0
[ 2538.461082] do_el0_svc+0x1c/0x28
[ 2538.461087] el0_svc+0x38/0x68
[ 2538.461090] el0t_64_sync_handler+0x68/0xbc
[ 2538.461093] el0t_64_sync+0x1a8/0x1ac
T1: T2:
sd_remove
del_gendisk
__blk_mark_disk_dead
blk_freeze_queue_start
++q->mq_freeze_depth
bdev_release
mutex_lock(&disk->open_mutex)
sd_release
scsi_execute_cmd
blk_queue_enter
wait_event(!q->mq_freeze_depth)
mutex_lock(&disk->open_mutex)
SCSI does not set GD_OWNS_QUEUE, so QUEUE_FLAG_DYING is not set in
this scenario. This is a classic ABBA deadlock. To fix the deadlock,
make sure we don't try to acquire disk->open_mutex after freezing
the queue. |
| In the Linux kernel, the following vulnerability has been resolved:
eth: sungem: remove .ndo_poll_controller to avoid deadlocks
Erhard reports netpoll warnings from sungem:
netpoll_send_skb_on_dev(): eth0 enabled interrupts in poll (gem_start_xmit+0x0/0x398)
WARNING: CPU: 1 PID: 1 at net/core/netpoll.c:370 netpoll_send_skb+0x1fc/0x20c
gem_poll_controller() disables interrupts, which may sleep.
We can't sleep in netpoll, it has interrupts disabled completely.
Strangely, gem_poll_controller() doesn't even poll the completions,
and instead acts as if an interrupt has fired so it just schedules
NAPI and exits. None of this has been necessary for years, since
netpoll invokes NAPI directly. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: Reload only IB representors upon lag disable/enable
On lag disable, the bond IB device along with all of its
representors are destroyed, and then the slaves' representors get reloaded.
In case the slave IB representor load fails, the eswitch error flow
unloads all representors, including ethernet representors, where the
netdevs get detached and removed from lag bond. Such flow is inaccurate
as the lag driver is not responsible for loading/unloading ethernet
representors. Furthermore, the flow described above begins by holding
lag lock to prevent bond changes during disable flow. However, when
reaching the ethernet representors detachment from lag, the lag lock is
required again, triggering the following deadlock:
Call trace:
__switch_to+0xf4/0x148
__schedule+0x2c8/0x7d0
schedule+0x50/0xe0
schedule_preempt_disabled+0x18/0x28
__mutex_lock.isra.13+0x2b8/0x570
__mutex_lock_slowpath+0x1c/0x28
mutex_lock+0x4c/0x68
mlx5_lag_remove_netdev+0x3c/0x1a0 [mlx5_core]
mlx5e_uplink_rep_disable+0x70/0xa0 [mlx5_core]
mlx5e_detach_netdev+0x6c/0xb0 [mlx5_core]
mlx5e_netdev_change_profile+0x44/0x138 [mlx5_core]
mlx5e_netdev_attach_nic_profile+0x28/0x38 [mlx5_core]
mlx5e_vport_rep_unload+0x184/0x1b8 [mlx5_core]
mlx5_esw_offloads_rep_load+0xd8/0xe0 [mlx5_core]
mlx5_eswitch_reload_reps+0x74/0xd0 [mlx5_core]
mlx5_disable_lag+0x130/0x138 [mlx5_core]
mlx5_lag_disable_change+0x6c/0x70 [mlx5_core] // hold ldev->lock
mlx5_devlink_eswitch_mode_set+0xc0/0x410 [mlx5_core]
devlink_nl_cmd_eswitch_set_doit+0xdc/0x180
genl_family_rcv_msg_doit.isra.17+0xe8/0x138
genl_rcv_msg+0xe4/0x220
netlink_rcv_skb+0x44/0x108
genl_rcv+0x40/0x58
netlink_unicast+0x198/0x268
netlink_sendmsg+0x1d4/0x418
sock_sendmsg+0x54/0x60
__sys_sendto+0xf4/0x120
__arm64_sys_sendto+0x30/0x40
el0_svc_common+0x8c/0x120
do_el0_svc+0x30/0xa0
el0_svc+0x20/0x30
el0_sync_handler+0x90/0xb8
el0_sync+0x160/0x180
Thus, upon lag enable/disable, load and unload only the IB representors
of the slaves preventing the deadlock mentioned above.
While at it, refactor the mlx5_esw_offloads_rep_load() function to have
a static helper method for its internal logic, in symmetry with the
representor unload design. |
| In the Linux kernel, the following vulnerability has been resolved:
Revert "media: v4l2-ctrls: show all owned controls in log_status"
This reverts commit 9801b5b28c6929139d6fceeee8d739cc67bb2739.
This patch introduced a potential deadlock scenario:
[Wed May 8 10:02:06 2024] Possible unsafe locking scenario:
[Wed May 8 10:02:06 2024] CPU0 CPU1
[Wed May 8 10:02:06 2024] ---- ----
[Wed May 8 10:02:06 2024] lock(vivid_ctrls:1620:(hdl_vid_cap)->_lock);
[Wed May 8 10:02:06 2024] lock(vivid_ctrls:1608:(hdl_user_vid)->_lock);
[Wed May 8 10:02:06 2024] lock(vivid_ctrls:1620:(hdl_vid_cap)->_lock);
[Wed May 8 10:02:06 2024] lock(vivid_ctrls:1608:(hdl_user_vid)->_lock);
For now just revert. |
| In the Linux kernel, the following vulnerability has been resolved:
Reapply "drm/qxl: simplify qxl_fence_wait"
This reverts commit 07ed11afb68d94eadd4ffc082b97c2331307c5ea.
Stephen Rostedt reports:
"I went to run my tests on my VMs and the tests hung on boot up.
Unfortunately, the most I ever got out was:
[ 93.607888] Testing event system initcall: OK
[ 93.667730] Running tests on all trace events:
[ 93.669757] Testing all events: OK
[ 95.631064] ------------[ cut here ]------------
Timed out after 60 seconds"
and further debugging points to a possible circular locking dependency
between the console_owner locking and the worker pool locking.
Reverting the commit allows Steve's VM to boot to completion again.
[ This may obviously result in the "[TTM] Buffer eviction failed"
messages again, which was the reason for that original revert. But at
this point this seems preferable to a non-booting system... ] |
| In the Linux kernel, the following vulnerability has been resolved:
mm: use memalloc_nofs_save() in page_cache_ra_order()
See commit f2c817bed58d ("mm: use memalloc_nofs_save in readahead path"),
ensure that page_cache_ra_order() do not attempt to reclaim file-backed
pages too, or it leads to a deadlock, found issue when test ext4 large
folio.
INFO: task DataXceiver for:7494 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:DataXceiver for state:D stack:0 pid:7494 ppid:1 flags:0x00000200
Call trace:
__switch_to+0x14c/0x240
__schedule+0x82c/0xdd0
schedule+0x58/0xf0
io_schedule+0x24/0xa0
__folio_lock+0x130/0x300
migrate_pages_batch+0x378/0x918
migrate_pages+0x350/0x700
compact_zone+0x63c/0xb38
compact_zone_order+0xc0/0x118
try_to_compact_pages+0xb0/0x280
__alloc_pages_direct_compact+0x98/0x248
__alloc_pages+0x510/0x1110
alloc_pages+0x9c/0x130
folio_alloc+0x20/0x78
filemap_alloc_folio+0x8c/0x1b0
page_cache_ra_order+0x174/0x308
ondemand_readahead+0x1c8/0x2b8
page_cache_async_ra+0x68/0xb8
filemap_readahead.isra.0+0x64/0xa8
filemap_get_pages+0x3fc/0x5b0
filemap_splice_read+0xf4/0x280
ext4_file_splice_read+0x2c/0x48 [ext4]
vfs_splice_read.part.0+0xa8/0x118
splice_direct_to_actor+0xbc/0x288
do_splice_direct+0x9c/0x108
do_sendfile+0x328/0x468
__arm64_sys_sendfile64+0x8c/0x148
invoke_syscall+0x4c/0x118
el0_svc_common.constprop.0+0xc8/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x4c/0x1f8
el0t_64_sync_handler+0xc0/0xc8
el0t_64_sync+0x188/0x190 |
| In the Linux kernel, the following vulnerability has been resolved:
block: fix deadlock between bd_link_disk_holder and partition scan
'open_mutex' of gendisk is used to protect open/close block devices. But
in bd_link_disk_holder(), it is used to protect the creation of symlink
between holding disk and slave bdev, which introduces some issues.
When bd_link_disk_holder() is called, the driver is usually in the process
of initialization/modification and may suspend submitting io. At this
time, any io hold 'open_mutex', such as scanning partitions, can cause
deadlocks. For example, in raid:
T1 T2
bdev_open_by_dev
lock open_mutex [1]
...
efi_partition
...
md_submit_bio
md_ioctl mddev_syspend
-> suspend all io
md_add_new_disk
bind_rdev_to_array
bd_link_disk_holder
try lock open_mutex [2]
md_handle_request
-> wait mddev_resume
T1 scan partition, T2 add a new device to raid. T1 waits for T2 to resume
mddev, but T2 waits for open_mutex held by T1. Deadlock occurs.
Fix it by introducing a local mutex 'blk_holder_mutex' to replace
'open_mutex'. |
