| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fail bpf_timer_cancel when callback is being cancelled
Given a schedule:
timer1 cb timer2 cb
bpf_timer_cancel(timer2); bpf_timer_cancel(timer1);
Both bpf_timer_cancel calls would wait for the other callback to finish
executing, introducing a lockup.
Add an atomic_t count named 'cancelling' in bpf_hrtimer. This keeps
track of all in-flight cancellation requests for a given BPF timer.
Whenever cancelling a BPF timer, we must check if we have outstanding
cancellation requests, and if so, we must fail the operation with an
error (-EDEADLK) since cancellation is synchronous and waits for the
callback to finish executing. This implies that we can enter a deadlock
situation involving two or more timer callbacks executing in parallel
and attempting to cancel one another.
Note that we avoid incrementing the cancelling counter for the target
timer (the one being cancelled) if bpf_timer_cancel is not invoked from
a callback, to avoid spurious errors. The whole point of detecting
cur->cancelling and returning -EDEADLK is to not enter a busy wait loop
(which may or may not lead to a lockup). This does not apply in case the
caller is in a non-callback context, the other side can continue to
cancel as it sees fit without running into errors.
Background on prior attempts:
Earlier versions of this patch used a bool 'cancelling' bit and used the
following pattern under timer->lock to publish cancellation status.
lock(t->lock);
t->cancelling = true;
mb();
if (cur->cancelling)
return -EDEADLK;
unlock(t->lock);
hrtimer_cancel(t->timer);
t->cancelling = false;
The store outside the critical section could overwrite a parallel
requests t->cancelling assignment to true, to ensure the parallely
executing callback observes its cancellation status.
It would be necessary to clear this cancelling bit once hrtimer_cancel
is done, but lack of serialization introduced races. Another option was
explored where bpf_timer_start would clear the bit when (re)starting the
timer under timer->lock. This would ensure serialized access to the
cancelling bit, but may allow it to be cleared before in-flight
hrtimer_cancel has finished executing, such that lockups can occur
again.
Thus, we choose an atomic counter to keep track of all outstanding
cancellation requests and use it to prevent lockups in case callbacks
attempt to cancel each other while executing in parallel. |
| 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:
wifi: iwlwifi: Use request_module_nowait
This appears to work around a deadlock regression that came in
with the LED merge in 6.9.
The deadlock happens on my system with 24 iwlwifi radios, so maybe
it something like all worker threads are busy and some work that needs
to complete cannot complete.
[also remove unnecessary "load_module" var and now-wrong comment] |
| 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:
ice: fix LAG and VF lock dependency in ice_reset_vf()
9f74a3dfcf83 ("ice: Fix VF Reset paths when interface in a failed over
aggregate"), the ice driver has acquired the LAG mutex in ice_reset_vf().
The commit placed this lock acquisition just prior to the acquisition of
the VF configuration lock.
If ice_reset_vf() acquires the configuration lock via the ICE_VF_RESET_LOCK
flag, this could deadlock with ice_vc_cfg_qs_msg() because it always
acquires the locks in the order of the VF configuration lock and then the
LAG mutex.
Lockdep reports this violation almost immediately on creating and then
removing 2 VF:
======================================================
WARNING: possible circular locking dependency detected
6.8.0-rc6 #54 Tainted: G W O
------------------------------------------------------
kworker/60:3/6771 is trying to acquire lock:
ff40d43e099380a0 (&vf->cfg_lock){+.+.}-{3:3}, at: ice_reset_vf+0x22f/0x4d0 [ice]
but task is already holding lock:
ff40d43ea1961210 (&pf->lag_mutex){+.+.}-{3:3}, at: ice_reset_vf+0xb7/0x4d0 [ice]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&pf->lag_mutex){+.+.}-{3:3}:
__lock_acquire+0x4f8/0xb40
lock_acquire+0xd4/0x2d0
__mutex_lock+0x9b/0xbf0
ice_vc_cfg_qs_msg+0x45/0x690 [ice]
ice_vc_process_vf_msg+0x4f5/0x870 [ice]
__ice_clean_ctrlq+0x2b5/0x600 [ice]
ice_service_task+0x2c9/0x480 [ice]
process_one_work+0x1e9/0x4d0
worker_thread+0x1e1/0x3d0
kthread+0x104/0x140
ret_from_fork+0x31/0x50
ret_from_fork_asm+0x1b/0x30
-> #0 (&vf->cfg_lock){+.+.}-{3:3}:
check_prev_add+0xe2/0xc50
validate_chain+0x558/0x800
__lock_acquire+0x4f8/0xb40
lock_acquire+0xd4/0x2d0
__mutex_lock+0x9b/0xbf0
ice_reset_vf+0x22f/0x4d0 [ice]
ice_process_vflr_event+0x98/0xd0 [ice]
ice_service_task+0x1cc/0x480 [ice]
process_one_work+0x1e9/0x4d0
worker_thread+0x1e1/0x3d0
kthread+0x104/0x140
ret_from_fork+0x31/0x50
ret_from_fork_asm+0x1b/0x30
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&pf->lag_mutex);
lock(&vf->cfg_lock);
lock(&pf->lag_mutex);
lock(&vf->cfg_lock);
*** DEADLOCK ***
4 locks held by kworker/60:3/6771:
#0: ff40d43e05428b38 ((wq_completion)ice){+.+.}-{0:0}, at: process_one_work+0x176/0x4d0
#1: ff50d06e05197e58 ((work_completion)(&pf->serv_task)){+.+.}-{0:0}, at: process_one_work+0x176/0x4d0
#2: ff40d43ea1960e50 (&pf->vfs.table_lock){+.+.}-{3:3}, at: ice_process_vflr_event+0x48/0xd0 [ice]
#3: ff40d43ea1961210 (&pf->lag_mutex){+.+.}-{3:3}, at: ice_reset_vf+0xb7/0x4d0 [ice]
stack backtrace:
CPU: 60 PID: 6771 Comm: kworker/60:3 Tainted: G W O 6.8.0-rc6 #54
Hardware name:
Workqueue: ice ice_service_task [ice]
Call Trace:
<TASK>
dump_stack_lvl+0x4a/0x80
check_noncircular+0x12d/0x150
check_prev_add+0xe2/0xc50
? save_trace+0x59/0x230
? add_chain_cache+0x109/0x450
validate_chain+0x558/0x800
__lock_acquire+0x4f8/0xb40
? lockdep_hardirqs_on+0x7d/0x100
lock_acquire+0xd4/0x2d0
? ice_reset_vf+0x22f/0x4d0 [ice]
? lock_is_held_type+0xc7/0x120
__mutex_lock+0x9b/0xbf0
? ice_reset_vf+0x22f/0x4d0 [ice]
? ice_reset_vf+0x22f/0x4d0 [ice]
? rcu_is_watching+0x11/0x50
? ice_reset_vf+0x22f/0x4d0 [ice]
ice_reset_vf+0x22f/0x4d0 [ice]
? process_one_work+0x176/0x4d0
ice_process_vflr_event+0x98/0xd0 [ice]
ice_service_task+0x1cc/0x480 [ice]
process_one_work+0x1e9/0x4d0
worker_thread+0x1e1/0x3d0
? __pfx_worker_thread+0x10/0x10
kthread+0x104/0x140
? __pfx_kthread+0x10/0x10
ret_from_fork+0x31/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
To avoid deadlock, we must acquire the LAG
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
HID: i2c-hid: remove I2C_HID_READ_PENDING flag to prevent lock-up
The flag I2C_HID_READ_PENDING is used to serialize I2C operations.
However, this is not necessary, because I2C core already has its own
locking for that.
More importantly, this flag can cause a lock-up: if the flag is set in
i2c_hid_xfer() and an interrupt happens, the interrupt handler
(i2c_hid_irq) will check this flag and return immediately without doing
anything, then the interrupt handler will be invoked again in an
infinite loop.
Since interrupt handler is an RT task, it takes over the CPU and the
flag-clearing task never gets scheduled, thus we have a lock-up.
Delete this unnecessary flag. |
| In the Linux kernel, the following vulnerability has been resolved:
dma: xilinx_dpdma: Fix locking
There are several places where either chan->lock or chan->vchan.lock was
not held. Add appropriate locking. This fixes lockdep warnings like
[ 31.077578] ------------[ cut here ]------------
[ 31.077831] WARNING: CPU: 2 PID: 40 at drivers/dma/xilinx/xilinx_dpdma.c:834 xilinx_dpdma_chan_queue_transfer+0x274/0x5e0
[ 31.077953] Modules linked in:
[ 31.078019] CPU: 2 PID: 40 Comm: kworker/u12:1 Not tainted 6.6.20+ #98
[ 31.078102] Hardware name: xlnx,zynqmp (DT)
[ 31.078169] Workqueue: events_unbound deferred_probe_work_func
[ 31.078272] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 31.078377] pc : xilinx_dpdma_chan_queue_transfer+0x274/0x5e0
[ 31.078473] lr : xilinx_dpdma_chan_queue_transfer+0x270/0x5e0
[ 31.078550] sp : ffffffc083bb2e10
[ 31.078590] x29: ffffffc083bb2e10 x28: 0000000000000000 x27: ffffff880165a168
[ 31.078754] x26: ffffff880164e920 x25: ffffff880164eab8 x24: ffffff880164d480
[ 31.078920] x23: ffffff880165a148 x22: ffffff880164e988 x21: 0000000000000000
[ 31.079132] x20: ffffffc082aa3000 x19: ffffff880164e880 x18: 0000000000000000
[ 31.079295] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
[ 31.079453] x14: 0000000000000000 x13: ffffff8802263dc0 x12: 0000000000000001
[ 31.079613] x11: 0001ffc083bb2e34 x10: 0001ff880164e98f x9 : 0001ffc082aa3def
[ 31.079824] x8 : 0001ffc082aa3dec x7 : 0000000000000000 x6 : 0000000000000516
[ 31.079982] x5 : ffffffc7f8d43000 x4 : ffffff88003c9c40 x3 : ffffffffffffffff
[ 31.080147] x2 : ffffffc7f8d43000 x1 : 00000000000000c0 x0 : 0000000000000000
[ 31.080307] Call trace:
[ 31.080340] xilinx_dpdma_chan_queue_transfer+0x274/0x5e0
[ 31.080518] xilinx_dpdma_issue_pending+0x11c/0x120
[ 31.080595] zynqmp_disp_layer_update+0x180/0x3ac
[ 31.080712] zynqmp_dpsub_plane_atomic_update+0x11c/0x21c
[ 31.080825] drm_atomic_helper_commit_planes+0x20c/0x684
[ 31.080951] drm_atomic_helper_commit_tail+0x5c/0xb0
[ 31.081139] commit_tail+0x234/0x294
[ 31.081246] drm_atomic_helper_commit+0x1f8/0x210
[ 31.081363] drm_atomic_commit+0x100/0x140
[ 31.081477] drm_client_modeset_commit_atomic+0x318/0x384
[ 31.081634] drm_client_modeset_commit_locked+0x8c/0x24c
[ 31.081725] drm_client_modeset_commit+0x34/0x5c
[ 31.081812] __drm_fb_helper_restore_fbdev_mode_unlocked+0x104/0x168
[ 31.081899] drm_fb_helper_set_par+0x50/0x70
[ 31.081971] fbcon_init+0x538/0xc48
[ 31.082047] visual_init+0x16c/0x23c
[ 31.082207] do_bind_con_driver.isra.0+0x2d0/0x634
[ 31.082320] do_take_over_console+0x24c/0x33c
[ 31.082429] do_fbcon_takeover+0xbc/0x1b0
[ 31.082503] fbcon_fb_registered+0x2d0/0x34c
[ 31.082663] register_framebuffer+0x27c/0x38c
[ 31.082767] __drm_fb_helper_initial_config_and_unlock+0x5c0/0x91c
[ 31.082939] drm_fb_helper_initial_config+0x50/0x74
[ 31.083012] drm_fbdev_dma_client_hotplug+0xb8/0x108
[ 31.083115] drm_client_register+0xa0/0xf4
[ 31.083195] drm_fbdev_dma_setup+0xb0/0x1cc
[ 31.083293] zynqmp_dpsub_drm_init+0x45c/0x4e0
[ 31.083431] zynqmp_dpsub_probe+0x444/0x5e0
[ 31.083616] platform_probe+0x8c/0x13c
[ 31.083713] really_probe+0x258/0x59c
[ 31.083793] __driver_probe_device+0xc4/0x224
[ 31.083878] driver_probe_device+0x70/0x1c0
[ 31.083961] __device_attach_driver+0x108/0x1e0
[ 31.084052] bus_for_each_drv+0x9c/0x100
[ 31.084125] __device_attach+0x100/0x298
[ 31.084207] device_initial_probe+0x14/0x20
[ 31.084292] bus_probe_device+0xd8/0xdc
[ 31.084368] deferred_probe_work_func+0x11c/0x180
[ 31.084451] process_one_work+0x3ac/0x988
[ 31.084643] worker_thread+0x398/0x694
[ 31.084752] kthread+0x1bc/0x1c0
[ 31.084848] ret_from_fork+0x10/0x20
[ 31.084932] irq event stamp: 64549
[ 31.084970] hardirqs last enabled at (64548): [<ffffffc081adf35c>] _raw_spin_unlock_irqrestore+0x80/0x90
[ 31.085157]
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
af_unix: Clear stale u->oob_skb.
syzkaller started to report deadlock of unix_gc_lock after commit
4090fa373f0e ("af_unix: Replace garbage collection algorithm."), but
it just uncovers the bug that has been there since commit 314001f0bf92
("af_unix: Add OOB support").
The repro basically does the following.
from socket import *
from array import array
c1, c2 = socketpair(AF_UNIX, SOCK_STREAM)
c1.sendmsg([b'a'], [(SOL_SOCKET, SCM_RIGHTS, array("i", [c2.fileno()]))], MSG_OOB)
c2.recv(1) # blocked as no normal data in recv queue
c2.close() # done async and unblock recv()
c1.close() # done async and trigger GC
A socket sends its file descriptor to itself as OOB data and tries to
receive normal data, but finally recv() fails due to async close().
The problem here is wrong handling of OOB skb in manage_oob(). When
recvmsg() is called without MSG_OOB, manage_oob() is called to check
if the peeked skb is OOB skb. In such a case, manage_oob() pops it
out of the receive queue but does not clear unix_sock(sk)->oob_skb.
This is wrong in terms of uAPI.
Let's say we send "hello" with MSG_OOB, and "world" without MSG_OOB.
The 'o' is handled as OOB data. When recv() is called twice without
MSG_OOB, the OOB data should be lost.
>>> from socket import *
>>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM, 0)
>>> c1.send(b'hello', MSG_OOB) # 'o' is OOB data
5
>>> c1.send(b'world')
5
>>> c2.recv(5) # OOB data is not received
b'hell'
>>> c2.recv(5) # OOB date is skipped
b'world'
>>> c2.recv(5, MSG_OOB) # This should return an error
b'o'
In the same situation, TCP actually returns -EINVAL for the last
recv().
Also, if we do not clear unix_sk(sk)->oob_skb, unix_poll() always set
EPOLLPRI even though the data has passed through by previous recv().
To avoid these issues, we must clear unix_sk(sk)->oob_skb when dequeuing
it from recv queue.
The reason why the old GC did not trigger the deadlock is because the
old GC relied on the receive queue to detect the loop.
When it is triggered, the socket with OOB data is marked as GC candidate
because file refcount == inflight count (1). However, after traversing
all inflight sockets, the socket still has a positive inflight count (1),
thus the socket is excluded from candidates. Then, the old GC lose the
chance to garbage-collect the socket.
With the old GC, the repro continues to create true garbage that will
never be freed nor detected by kmemleak as it's linked to the global
inflight list. That's why we couldn't even notice the issue. |
| In the Linux kernel, the following vulnerability has been resolved:
pds_core: Fix pdsc_check_pci_health function to use work thread
When the driver notices fw_status == 0xff it tries to perform a PCI
reset on itself via pci_reset_function() in the context of the driver's
health thread. However, pdsc_reset_prepare calls
pdsc_stop_health_thread(), which attempts to stop/flush the health
thread. This results in a deadlock because the stop/flush will never
complete since the driver called pci_reset_function() from the health
thread context. Fix by changing the pdsc_check_pci_health_function()
to queue a newly introduced pdsc_pci_reset_thread() on the pdsc's
work queue.
Unloading the driver in the fw_down/dead state uncovered another issue,
which can be seen in the following trace:
WARNING: CPU: 51 PID: 6914 at kernel/workqueue.c:1450 __queue_work+0x358/0x440
[...]
RIP: 0010:__queue_work+0x358/0x440
[...]
Call Trace:
<TASK>
? __warn+0x85/0x140
? __queue_work+0x358/0x440
? report_bug+0xfc/0x1e0
? handle_bug+0x3f/0x70
? exc_invalid_op+0x17/0x70
? asm_exc_invalid_op+0x1a/0x20
? __queue_work+0x358/0x440
queue_work_on+0x28/0x30
pdsc_devcmd_locked+0x96/0xe0 [pds_core]
pdsc_devcmd_reset+0x71/0xb0 [pds_core]
pdsc_teardown+0x51/0xe0 [pds_core]
pdsc_remove+0x106/0x200 [pds_core]
pci_device_remove+0x37/0xc0
device_release_driver_internal+0xae/0x140
driver_detach+0x48/0x90
bus_remove_driver+0x6d/0xf0
pci_unregister_driver+0x2e/0xa0
pdsc_cleanup_module+0x10/0x780 [pds_core]
__x64_sys_delete_module+0x142/0x2b0
? syscall_trace_enter.isra.18+0x126/0x1a0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7fbd9d03a14b
[...]
Fix this by preventing the devcmd reset if the FW is not running. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/ivpu: Fix deadlock in context_xa
ivpu_device->context_xa is locked both in kernel thread and IRQ context.
It requires XA_FLAGS_LOCK_IRQ flag to be passed during initialization
otherwise the lock could be acquired from a thread and interrupted by
an IRQ that locks it for the second time causing the deadlock.
This deadlock was reported by lockdep and observed in internal tests. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Prevent lock inversion deadlock in map delete elem
syzkaller started using corpuses where a BPF tracing program deletes
elements from a sockmap/sockhash map. Because BPF tracing programs can be
invoked from any interrupt context, locks taken during a map_delete_elem
operation must be hardirq-safe. Otherwise a deadlock due to lock inversion
is possible, as reported by lockdep:
CPU0 CPU1
---- ----
lock(&htab->buckets[i].lock);
local_irq_disable();
lock(&host->lock);
lock(&htab->buckets[i].lock);
<Interrupt>
lock(&host->lock);
Locks in sockmap are hardirq-unsafe by design. We expects elements to be
deleted from sockmap/sockhash only in task (normal) context with interrupts
enabled, or in softirq context.
Detect when map_delete_elem operation is invoked from a context which is
_not_ hardirq-unsafe, that is interrupts are disabled, and bail out with an
error.
Note that map updates are not affected by this issue. BPF verifier does not
allow updating sockmap/sockhash from a BPF tracing program today. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix deadlock while reading mqd from debugfs
An errant disk backup on my desktop got into debugfs and triggered the
following deadlock scenario in the amdgpu debugfs files. The machine
also hard-resets immediately after those lines are printed (although I
wasn't able to reproduce that part when reading by hand):
[ 1318.016074][ T1082] ======================================================
[ 1318.016607][ T1082] WARNING: possible circular locking dependency detected
[ 1318.017107][ T1082] 6.8.0-rc7-00015-ge0c8221b72c0 #17 Not tainted
[ 1318.017598][ T1082] ------------------------------------------------------
[ 1318.018096][ T1082] tar/1082 is trying to acquire lock:
[ 1318.018585][ T1082] ffff98c44175d6a0 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x40/0x80
[ 1318.019084][ T1082]
[ 1318.019084][ T1082] but task is already holding lock:
[ 1318.020052][ T1082] ffff98c4c13f55f8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: amdgpu_debugfs_mqd_read+0x6a/0x250 [amdgpu]
[ 1318.020607][ T1082]
[ 1318.020607][ T1082] which lock already depends on the new lock.
[ 1318.020607][ T1082]
[ 1318.022081][ T1082]
[ 1318.022081][ T1082] the existing dependency chain (in reverse order) is:
[ 1318.023083][ T1082]
[ 1318.023083][ T1082] -> #2 (reservation_ww_class_mutex){+.+.}-{3:3}:
[ 1318.024114][ T1082] __ww_mutex_lock.constprop.0+0xe0/0x12f0
[ 1318.024639][ T1082] ww_mutex_lock+0x32/0x90
[ 1318.025161][ T1082] dma_resv_lockdep+0x18a/0x330
[ 1318.025683][ T1082] do_one_initcall+0x6a/0x350
[ 1318.026210][ T1082] kernel_init_freeable+0x1a3/0x310
[ 1318.026728][ T1082] kernel_init+0x15/0x1a0
[ 1318.027242][ T1082] ret_from_fork+0x2c/0x40
[ 1318.027759][ T1082] ret_from_fork_asm+0x11/0x20
[ 1318.028281][ T1082]
[ 1318.028281][ T1082] -> #1 (reservation_ww_class_acquire){+.+.}-{0:0}:
[ 1318.029297][ T1082] dma_resv_lockdep+0x16c/0x330
[ 1318.029790][ T1082] do_one_initcall+0x6a/0x350
[ 1318.030263][ T1082] kernel_init_freeable+0x1a3/0x310
[ 1318.030722][ T1082] kernel_init+0x15/0x1a0
[ 1318.031168][ T1082] ret_from_fork+0x2c/0x40
[ 1318.031598][ T1082] ret_from_fork_asm+0x11/0x20
[ 1318.032011][ T1082]
[ 1318.032011][ T1082] -> #0 (&mm->mmap_lock){++++}-{3:3}:
[ 1318.032778][ T1082] __lock_acquire+0x14bf/0x2680
[ 1318.033141][ T1082] lock_acquire+0xcd/0x2c0
[ 1318.033487][ T1082] __might_fault+0x58/0x80
[ 1318.033814][ T1082] amdgpu_debugfs_mqd_read+0x103/0x250 [amdgpu]
[ 1318.034181][ T1082] full_proxy_read+0x55/0x80
[ 1318.034487][ T1082] vfs_read+0xa7/0x360
[ 1318.034788][ T1082] ksys_read+0x70/0xf0
[ 1318.035085][ T1082] do_syscall_64+0x94/0x180
[ 1318.035375][ T1082] entry_SYSCALL_64_after_hwframe+0x46/0x4e
[ 1318.035664][ T1082]
[ 1318.035664][ T1082] other info that might help us debug this:
[ 1318.035664][ T1082]
[ 1318.036487][ T1082] Chain exists of:
[ 1318.036487][ T1082] &mm->mmap_lock --> reservation_ww_class_acquire --> reservation_ww_class_mutex
[ 1318.036487][ T1082]
[ 1318.037310][ T1082] Possible unsafe locking scenario:
[ 1318.037310][ T1082]
[ 1318.037838][ T1082] CPU0 CPU1
[ 1318.038101][ T1082] ---- ----
[ 1318.038350][ T1082] lock(reservation_ww_class_mutex);
[ 1318.038590][ T1082] lock(reservation_ww_class_acquire);
[ 1318.038839][ T1082] lock(reservation_ww_class_mutex);
[ 1318.039083][ T1082] rlock(&mm->mmap_lock);
[ 1318.039328][ T1082]
[ 1318.039328][ T1082] *** DEADLOCK ***
[ 1318.039328][ T1082]
[ 1318.040029][ T1082] 1 lock held by tar/1082:
[ 1318.040259][ T1082] #0: ffff98c4c13f55f8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: amdgpu_debugfs_mqd_read+0x6a/0x250 [amdgpu]
[ 1318.040560][ T1082]
[ 1318.040560][ T1082] stack backtrace:
[
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
drm/nouveau: fix stale locked mutex in nouveau_gem_ioctl_pushbuf
If VM_BIND is enabled on the client the legacy submission ioctl can't be
used, however if a client tries to do so regardless it will return an
error. In this case the clients mutex remained unlocked leading to a
deadlock inside nouveau_drm_postclose or any other nouveau ioctl call. |
| In the Linux kernel, the following vulnerability has been resolved:
NFS: Fix nfs_netfs_issue_read() xarray locking for writeback interrupt
The loop inside nfs_netfs_issue_read() currently does not disable
interrupts while iterating through pages in the xarray to submit
for NFS read. This is not safe though since after taking xa_lock,
another page in the mapping could be processed for writeback inside
an interrupt, and deadlock can occur. The fix is simple and clean
if we use xa_for_each_range(), which handles the iteration with RCU
while reducing code complexity.
The problem is easily reproduced with the following test:
mount -o vers=3,fsc 127.0.0.1:/export /mnt/nfs
dd if=/dev/zero of=/mnt/nfs/file1.bin bs=4096 count=1
echo 3 > /proc/sys/vm/drop_caches
dd if=/mnt/nfs/file1.bin of=/dev/null
umount /mnt/nfs
On the console with a lockdep-enabled kernel a message similar to
the following will be seen:
================================
WARNING: inconsistent lock state
6.7.0-lockdbg+ #10 Not tainted
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
test5/1708 [HC0[0]:SC0[0]:HE1:SE1] takes:
ffff888127baa598 (&xa->xa_lock#4){+.?.}-{3:3}, at:
nfs_netfs_issue_read+0x1b2/0x4b0 [nfs]
{IN-SOFTIRQ-W} state was registered at:
lock_acquire+0x144/0x380
_raw_spin_lock_irqsave+0x4e/0xa0
__folio_end_writeback+0x17e/0x5c0
folio_end_writeback+0x93/0x1b0
iomap_finish_ioend+0xeb/0x6a0
blk_update_request+0x204/0x7f0
blk_mq_end_request+0x30/0x1c0
blk_complete_reqs+0x7e/0xa0
__do_softirq+0x113/0x544
__irq_exit_rcu+0xfe/0x120
irq_exit_rcu+0xe/0x20
sysvec_call_function_single+0x6f/0x90
asm_sysvec_call_function_single+0x1a/0x20
pv_native_safe_halt+0xf/0x20
default_idle+0x9/0x20
default_idle_call+0x67/0xa0
do_idle+0x2b5/0x300
cpu_startup_entry+0x34/0x40
start_secondary+0x19d/0x1c0
secondary_startup_64_no_verify+0x18f/0x19b
irq event stamp: 176891
hardirqs last enabled at (176891): [<ffffffffa67a0be4>]
_raw_spin_unlock_irqrestore+0x44/0x60
hardirqs last disabled at (176890): [<ffffffffa67a0899>]
_raw_spin_lock_irqsave+0x79/0xa0
softirqs last enabled at (176646): [<ffffffffa515d91e>]
__irq_exit_rcu+0xfe/0x120
softirqs last disabled at (176633): [<ffffffffa515d91e>]
__irq_exit_rcu+0xfe/0x120
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&xa->xa_lock#4);
<Interrupt>
lock(&xa->xa_lock#4);
*** DEADLOCK ***
2 locks held by test5/1708:
#0: ffff888127baa498 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at:
nfs_start_io_read+0x28/0x90 [nfs]
#1: ffff888127baa650 (mapping.invalidate_lock#3){.+.+}-{4:4}, at:
page_cache_ra_unbounded+0xa4/0x280
stack backtrace:
CPU: 6 PID: 1708 Comm: test5 Kdump: loaded Not tainted 6.7.0-lockdbg+
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39
04/01/2014
Call Trace:
dump_stack_lvl+0x5b/0x90
mark_lock+0xb3f/0xd20
__lock_acquire+0x77b/0x3360
_raw_spin_lock+0x34/0x80
nfs_netfs_issue_read+0x1b2/0x4b0 [nfs]
netfs_begin_read+0x77f/0x980 [netfs]
nfs_netfs_readahead+0x45/0x60 [nfs]
nfs_readahead+0x323/0x5a0 [nfs]
read_pages+0xf3/0x5c0
page_cache_ra_unbounded+0x1c8/0x280
filemap_get_pages+0x38c/0xae0
filemap_read+0x206/0x5e0
nfs_file_read+0xb7/0x140 [nfs]
vfs_read+0x2a9/0x460
ksys_read+0xb7/0x140 |
| In the Linux kernel, the following vulnerability has been resolved:
USB: core: Fix deadlock in usb_deauthorize_interface()
Among the attribute file callback routines in
drivers/usb/core/sysfs.c, the interface_authorized_store() function is
the only one which acquires a device lock on an ancestor device: It
calls usb_deauthorize_interface(), which locks the interface's parent
USB device.
The will lead to deadlock if another process already owns that lock
and tries to remove the interface, whether through a configuration
change or because the device has been disconnected. As part of the
removal procedure, device_del() waits for all ongoing sysfs attribute
callbacks to complete. But usb_deauthorize_interface() can't complete
until the device lock has been released, and the lock won't be
released until the removal has finished.
The mechanism provided by sysfs to prevent this kind of deadlock is
to use the sysfs_break_active_protection() function, which tells sysfs
not to wait for the attribute callback.
Reported-and-tested by: Yue Sun <samsun1006219@gmail.com>
Reported by: xingwei lee <xrivendell7@gmail.com> |
| In the Linux kernel, the following vulnerability has been resolved:
USB: core: Fix deadlock in port "disable" sysfs attribute
The show and store callback routines for the "disable" sysfs attribute
file in port.c acquire the device lock for the port's parent hub
device. This can cause problems if another process has locked the hub
to remove it or change its configuration:
Removing the hub or changing its configuration requires the
hub interface to be removed, which requires the port device
to be removed, and device_del() waits until all outstanding
sysfs attribute callbacks for the ports have returned. The
lock can't be released until then.
But the disable_show() or disable_store() routine can't return
until after it has acquired the lock.
The resulting deadlock can be avoided by calling
sysfs_break_active_protection(). This will cause the sysfs core not
to wait for the attribute's callback routine to return, allowing the
removal to proceed. The disadvantage is that after making this call,
there is no guarantee that the hub structure won't be deallocated at
any moment. To prevent this, we have to acquire a reference to it
first by calling hub_get(). |
| 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'. |
