In the Linux kernel, the following vulnerability has been resolved:

wifi: ar5523: Fix use-after-free on ar5523_cmd() timed out

syzkaller reported use-after-free with the stack trace like below [1]:

[ 38.960489][ C3] ==================================================================
[ 38.963216][ C3] BUG: KASAN: use-after-free in ar5523_cmd_tx_cb+0x220/0x240
[ 38.964950][ C3] Read of size 8 at addr ffff888048e03450 by task swapper/3/0
[ 38.966363][ C3]
[ 38.967053][ C3] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.0.0-09039-ga6afa4199d3d-dirty #18
[ 38.968464][ C3] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014
[ 38.969959][ C3] Call Trace:
[ 38.970841][ C3] <IRQ>
[ 38.971663][ C3] dump_stack_lvl+0xfc/0x174
[ 38.972620][ C3] print_report.cold+0x2c3/0x752
[ 38.973626][ C3] ? ar5523_cmd_tx_cb+0x220/0x240
[ 38.974644][ C3] kasan_report+0xb1/0x1d0
[ 38.975720][ C3] ? ar5523_cmd_tx_cb+0x220/0x240
[ 38.976831][ C3] ar5523_cmd_tx_cb+0x220/0x240
[ 38.978412][ C3] __usb_hcd_giveback_urb+0x353/0x5b0
[ 38.979755][ C3] usb_hcd_giveback_urb+0x385/0x430
[ 38.981266][ C3] dummy_timer+0x140c/0x34e0
[ 38.982925][ C3] ? notifier_call_chain+0xb5/0x1e0
[ 38.984761][ C3] ? rcu_read_lock_sched_held+0xb/0x60
[ 38.986242][ C3] ? lock_release+0x51c/0x790
[ 38.987323][ C3] ? _raw_read_unlock_irqrestore+0x37/0x70
[ 38.988483][ C3] ? __wake_up_common_lock+0xde/0x130
[ 38.989621][ C3] ? reacquire_held_locks+0x4a0/0x4a0
[ 38.990777][ C3] ? lock_acquire+0x472/0x550
[ 38.991919][ C3] ? rcu_read_lock_sched_held+0xb/0x60
[ 38.993138][ C3] ? lock_acquire+0x472/0x550
[ 38.994890][ C3] ? dummy_urb_enqueue+0x860/0x860
[ 38.996266][ C3] ? do_raw_spin_unlock+0x16f/0x230
[ 38.997670][ C3] ? dummy_urb_enqueue+0x860/0x860
[ 38.999116][ C3] call_timer_fn+0x1a0/0x6a0
[ 39.000668][ C3] ? add_timer_on+0x4a0/0x4a0
[ 39.002137][ C3] ? reacquire_held_locks+0x4a0/0x4a0
[ 39.003809][ C3] ? __next_timer_interrupt+0x226/0x2a0
[ 39.005509][ C3] __run_timers.part.0+0x69a/0xac0
[ 39.007025][ C3] ? dummy_urb_enqueue+0x860/0x860
[ 39.008716][ C3] ? call_timer_fn+0x6a0/0x6a0
[ 39.010254][ C3] ? cpuacct_percpu_seq_show+0x10/0x10
[ 39.011795][ C3] ? kvm_sched_clock_read+0x14/0x40
[ 39.013277][ C3] ? sched_clock_cpu+0x69/0x2b0
[ 39.014724][ C3] run_timer_softirq+0xb6/0x1d0
[ 39.016196][ C3] __do_softirq+0x1d2/0x9be
[ 39.017616][ C3] __irq_exit_rcu+0xeb/0x190
[ 39.019004][ C3] irq_exit_rcu+0x5/0x20
[ 39.020361][ C3] sysvec_apic_timer_interrupt+0x8f/0xb0
[ 39.021965][ C3] </IRQ>
[ 39.023237][ C3] <TASK>

In ar5523_probe(), ar5523_host_available() calls ar5523_cmd() as below
(there are other functions which finally call ar5523_cmd()):

ar5523_probe()
-> ar5523_host_available()
-> ar5523_cmd_read()
-> ar5523_cmd()

If ar5523_cmd() timed out, then ar5523_host_available() failed and
ar5523_probe() freed the device structure. So, ar5523_cmd_tx_cb()
might touch the freed structure.

This patch fixes this issue by canceling in-flight tx cmd if submitted
urb timed out.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 25 Dec 2025 12:15:00 +0000


Wed, 24 Dec 2025 12:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: wifi: ar5523: Fix use-after-free on ar5523_cmd() timed out syzkaller reported use-after-free with the stack trace like below [1]: [ 38.960489][ C3] ================================================================== [ 38.963216][ C3] BUG: KASAN: use-after-free in ar5523_cmd_tx_cb+0x220/0x240 [ 38.964950][ C3] Read of size 8 at addr ffff888048e03450 by task swapper/3/0 [ 38.966363][ C3] [ 38.967053][ C3] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.0.0-09039-ga6afa4199d3d-dirty #18 [ 38.968464][ C3] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 [ 38.969959][ C3] Call Trace: [ 38.970841][ C3] <IRQ> [ 38.971663][ C3] dump_stack_lvl+0xfc/0x174 [ 38.972620][ C3] print_report.cold+0x2c3/0x752 [ 38.973626][ C3] ? ar5523_cmd_tx_cb+0x220/0x240 [ 38.974644][ C3] kasan_report+0xb1/0x1d0 [ 38.975720][ C3] ? ar5523_cmd_tx_cb+0x220/0x240 [ 38.976831][ C3] ar5523_cmd_tx_cb+0x220/0x240 [ 38.978412][ C3] __usb_hcd_giveback_urb+0x353/0x5b0 [ 38.979755][ C3] usb_hcd_giveback_urb+0x385/0x430 [ 38.981266][ C3] dummy_timer+0x140c/0x34e0 [ 38.982925][ C3] ? notifier_call_chain+0xb5/0x1e0 [ 38.984761][ C3] ? rcu_read_lock_sched_held+0xb/0x60 [ 38.986242][ C3] ? lock_release+0x51c/0x790 [ 38.987323][ C3] ? _raw_read_unlock_irqrestore+0x37/0x70 [ 38.988483][ C3] ? __wake_up_common_lock+0xde/0x130 [ 38.989621][ C3] ? reacquire_held_locks+0x4a0/0x4a0 [ 38.990777][ C3] ? lock_acquire+0x472/0x550 [ 38.991919][ C3] ? rcu_read_lock_sched_held+0xb/0x60 [ 38.993138][ C3] ? lock_acquire+0x472/0x550 [ 38.994890][ C3] ? dummy_urb_enqueue+0x860/0x860 [ 38.996266][ C3] ? do_raw_spin_unlock+0x16f/0x230 [ 38.997670][ C3] ? dummy_urb_enqueue+0x860/0x860 [ 38.999116][ C3] call_timer_fn+0x1a0/0x6a0 [ 39.000668][ C3] ? add_timer_on+0x4a0/0x4a0 [ 39.002137][ C3] ? reacquire_held_locks+0x4a0/0x4a0 [ 39.003809][ C3] ? __next_timer_interrupt+0x226/0x2a0 [ 39.005509][ C3] __run_timers.part.0+0x69a/0xac0 [ 39.007025][ C3] ? dummy_urb_enqueue+0x860/0x860 [ 39.008716][ C3] ? call_timer_fn+0x6a0/0x6a0 [ 39.010254][ C3] ? cpuacct_percpu_seq_show+0x10/0x10 [ 39.011795][ C3] ? kvm_sched_clock_read+0x14/0x40 [ 39.013277][ C3] ? sched_clock_cpu+0x69/0x2b0 [ 39.014724][ C3] run_timer_softirq+0xb6/0x1d0 [ 39.016196][ C3] __do_softirq+0x1d2/0x9be [ 39.017616][ C3] __irq_exit_rcu+0xeb/0x190 [ 39.019004][ C3] irq_exit_rcu+0x5/0x20 [ 39.020361][ C3] sysvec_apic_timer_interrupt+0x8f/0xb0 [ 39.021965][ C3] </IRQ> [ 39.023237][ C3] <TASK> In ar5523_probe(), ar5523_host_available() calls ar5523_cmd() as below (there are other functions which finally call ar5523_cmd()): ar5523_probe() -> ar5523_host_available() -> ar5523_cmd_read() -> ar5523_cmd() If ar5523_cmd() timed out, then ar5523_host_available() failed and ar5523_probe() freed the device structure. So, ar5523_cmd_tx_cb() might touch the freed structure. This patch fixes this issue by canceling in-flight tx cmd if submitted urb timed out.
Title wifi: ar5523: Fix use-after-free on ar5523_cmd() timed out
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-12-24T12:22:40.461Z

Reserved: 2025-12-24T12:20:40.329Z

Link: CVE-2022-50716

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-12-24T13:15:58.253

Modified: 2025-12-24T13:15:58.253

Link: CVE-2022-50716

cve-icon Redhat

Severity :

Publid Date: 2025-12-24T00:00:00Z

Links: CVE-2022-50716 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.