| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ARM: 9410/1: vfp: Use asm volatile in fmrx/fmxr macros
Floating point instructions in userspace can crash some arm kernels
built with clang/LLD 17.0.6:
BUG: unsupported FP instruction in kernel mode
FPEXC == 0xc0000780
Internal error: Oops - undefined instruction: 0 [#1] ARM
CPU: 0 PID: 196 Comm: vfp-reproducer Not tainted 6.10.0 #1
Hardware name: BCM2835
PC is at vfp_support_entry+0xc8/0x2cc
LR is at do_undefinstr+0xa8/0x250
pc : [<c0101d50>] lr : [<c010a80c>] psr: a0000013
sp : dc8d1f68 ip : 60000013 fp : bedea19c
r10: ec532b17 r9 : 00000010 r8 : 0044766c
r7 : c0000780 r6 : ec532b17 r5 : c1c13800 r4 : dc8d1fb0
r3 : c10072c4 r2 : c0101c88 r1 : ec532b17 r0 : 0044766c
Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
Control: 00c5387d Table: 0251c008 DAC: 00000051
Register r0 information: non-paged memory
Register r1 information: vmalloc memory
Register r2 information: non-slab/vmalloc memory
Register r3 information: non-slab/vmalloc memory
Register r4 information: 2-page vmalloc region
Register r5 information: slab kmalloc-cg-2k
Register r6 information: vmalloc memory
Register r7 information: non-slab/vmalloc memory
Register r8 information: non-paged memory
Register r9 information: zero-size pointer
Register r10 information: vmalloc memory
Register r11 information: non-paged memory
Register r12 information: non-paged memory
Process vfp-reproducer (pid: 196, stack limit = 0x61aaaf8b)
Stack: (0xdc8d1f68 to 0xdc8d2000)
1f60: 0000081f b6f69300 0000000f c10073f4 c10072c4 dc8d1fb0
1f80: ec532b17 0c532b17 0044766c b6f9ccd8 00000000 c010a80c 00447670 60000010
1fa0: ffffffff c1c13800 00c5387d c0100f10 b6f68af8 00448fc0 00000000 bedea188
1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c
1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff 00000000 00000000
Call trace:
[<c0101d50>] (vfp_support_entry) from [<c010a80c>] (do_undefinstr+0xa8/0x250)
[<c010a80c>] (do_undefinstr) from [<c0100f10>] (__und_usr+0x70/0x80)
Exception stack(0xdc8d1fb0 to 0xdc8d1ff8)
1fa0: b6f68af8 00448fc0 00000000 bedea188
1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c
1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff
Code: 0a000061 e3877202 e594003c e3a09010 (eef16a10)
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Fatal exception in interrupt
---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---
This is a minimal userspace reproducer on a Raspberry Pi Zero W:
#include <stdio.h>
#include <math.h>
int main(void)
{
double v = 1.0;
printf("%fn", NAN + *(volatile double *)&v);
return 0;
}
Another way to consistently trigger the oops is:
calvin@raspberry-pi-zero-w ~$ python -c "import json"
The bug reproduces only when the kernel is built with DYNAMIC_DEBUG=n,
because the pr_debug() calls act as barriers even when not activated.
This is the output from the same kernel source built with the same
compiler and DYNAMIC_DEBUG=y, where the userspace reproducer works as
expected:
VFP: bounce: trigger ec532b17 fpexc c0000780
VFP: emulate: INST=0xee377b06 SCR=0x00000000
VFP: bounce: trigger eef1fa10 fpexc c0000780
VFP: emulate: INST=0xeeb40b40 SCR=0x00000000
VFP: raising exceptions 30000000
calvin@raspberry-pi-zero-w ~$ ./vfp-reproducer
nan
Crudely grepping for vmsr/vmrs instructions in the otherwise nearly
idential text for vfp_support_entry() makes the problem obvious:
vmlinux.llvm.good [0xc0101cb8] <+48>: vmrs r7, fpexc
vmlinux.llvm.good [0xc0101cd8] <+80>: vmsr fpexc, r0
vmlinux.llvm.good [0xc0101d20
---truncated--- |
| 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:
drm/amdgpu/vcn: remove irq disabling in vcn 5 suspend
We do not directly enable/disable VCN IRQ in vcn 5.0.0.
And we do not handle the IRQ state as well. So the calls to
disable IRQ and set state are removed. This effectively gets
rid of the warining of
"WARN_ON(!amdgpu_irq_enabled(adev, src, type))"
in amdgpu_irq_put(). |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc/qspinlock: Fix deadlock in MCS queue
If an interrupt occurs in queued_spin_lock_slowpath() after we increment
qnodesp->count and before node->lock is initialized, another CPU might
see stale lock values in get_tail_qnode(). If the stale lock value happens
to match the lock on that CPU, then we write to the "next" pointer of
the wrong qnode. This causes a deadlock as the former CPU, once it becomes
the head of the MCS queue, will spin indefinitely until it's "next" pointer
is set by its successor in the queue.
Running stress-ng on a 16 core (16EC/16VP) shared LPAR, results in
occasional lockups similar to the following:
$ stress-ng --all 128 --vm-bytes 80% --aggressive \
--maximize --oomable --verify --syslog \
--metrics --times --timeout 5m
watchdog: CPU 15 Hard LOCKUP
......
NIP [c0000000000b78f4] queued_spin_lock_slowpath+0x1184/0x1490
LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90
Call Trace:
0xc000002cfffa3bf0 (unreliable)
_raw_spin_lock+0x6c/0x90
raw_spin_rq_lock_nested.part.135+0x4c/0xd0
sched_ttwu_pending+0x60/0x1f0
__flush_smp_call_function_queue+0x1dc/0x670
smp_ipi_demux_relaxed+0xa4/0x100
xive_muxed_ipi_action+0x20/0x40
__handle_irq_event_percpu+0x80/0x240
handle_irq_event_percpu+0x2c/0x80
handle_percpu_irq+0x84/0xd0
generic_handle_irq+0x54/0x80
__do_irq+0xac/0x210
__do_IRQ+0x74/0xd0
0x0
do_IRQ+0x8c/0x170
hardware_interrupt_common_virt+0x29c/0x2a0
--- interrupt: 500 at queued_spin_lock_slowpath+0x4b8/0x1490
......
NIP [c0000000000b6c28] queued_spin_lock_slowpath+0x4b8/0x1490
LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90
--- interrupt: 500
0xc0000029c1a41d00 (unreliable)
_raw_spin_lock+0x6c/0x90
futex_wake+0x100/0x260
do_futex+0x21c/0x2a0
sys_futex+0x98/0x270
system_call_exception+0x14c/0x2f0
system_call_vectored_common+0x15c/0x2ec
The following code flow illustrates how the deadlock occurs.
For the sake of brevity, assume that both locks (A and B) are
contended and we call the queued_spin_lock_slowpath() function.
CPU0 CPU1
---- ----
spin_lock_irqsave(A) |
spin_unlock_irqrestore(A) |
spin_lock(B) |
| |
▼ |
id = qnodesp->count++; |
(Note that nodes[0].lock == A) |
| |
▼ |
Interrupt |
(happens before "nodes[0].lock = B") |
| |
▼ |
spin_lock_irqsave(A) |
| |
▼ |
id = qnodesp->count++ |
nodes[1].lock = A |
| |
▼ |
Tail of MCS queue |
| spin_lock_irqsave(A)
▼ |
Head of MCS queue ▼
| CPU0 is previous tail
▼ |
Spin indefinitely ▼
(until "nodes[1].next != NULL") prev = get_tail_qnode(A, CPU0)
|
▼
prev == &qnodes[CPU0].nodes[0]
(as qnodes
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
firmware: qcom: scm: Mark get_wq_ctx() as atomic call
Currently get_wq_ctx() is wrongly configured as a standard call. When two
SMC calls are in sleep and one SMC wakes up, it calls get_wq_ctx() to
resume the corresponding sleeping thread. But if get_wq_ctx() is
interrupted, goes to sleep and another SMC call is waiting to be allocated
a waitq context, it leads to a deadlock.
To avoid this get_wq_ctx() must be an atomic call and can't be a standard
SMC call. Hence mark get_wq_ctx() as a fast call. |
| In the Linux kernel, the following vulnerability has been resolved:
pktgen: use cpus_read_lock() in pg_net_init()
I have seen the WARN_ON(smp_processor_id() != cpu) firing
in pktgen_thread_worker() during tests.
We must use cpus_read_lock()/cpus_read_unlock()
around the for_each_online_cpu(cpu) loop.
While we are at it use WARN_ON_ONCE() to avoid a possible syslog flood. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/preempt_fence: enlarge the fence critical section
It is really easy to introduce subtle deadlocks in
preempt_fence_work_func() since we operate on single global ordered-wq
for signalling our preempt fences behind the scenes, so even though we
signal a particular fence, everything in the callback should be in the
fence critical section, since blocking in the callback will prevent
other published fences from signalling. If we enlarge the fence critical
section to cover the entire callback, then lockdep should be able to
understand this better, and complain if we grab a sensitive lock like
vm->lock, which is also held when waiting on preempt fences. |
| 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:
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:
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. |
