CVE-2022-50426

Published Oct 1, 2025

Last updated 9 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: remoteproc: imx_dsp_rproc: Add mutex protection for workqueue The workqueue may execute late even after remoteproc is stopped or stopping, some resources (rpmsg device and endpoint) have been released in rproc_stop_subdevices(), then rproc_vq_interrupt() accessing these resources will cause kennel dump. Call trace: virtqueue_add_split+0x1ac/0x560 virtqueue_add_inbuf+0x4c/0x60 rpmsg_recv_done+0x15c/0x294 vring_interrupt+0x6c/0xa4 rproc_vq_interrupt+0x30/0x50 imx_dsp_rproc_vq_work+0x24/0x40 [imx_dsp_rproc] process_one_work+0x1d0/0x354 worker_thread+0x13c/0x470 kthread+0x154/0x160 ret_from_fork+0x10/0x20 Add mutex protection in imx_dsp_rproc_vq_work(), if the state is not running, then just skip calling rproc_vq_interrupt(). Also the flush workqueue operation can't be added in rproc stop for the same reason. The call sequence is rproc_shutdown -> rproc_stop ->rproc_stop_subdevices ->rproc->ops->stop() ->imx_dsp_rproc_stop ->flush_work -> rproc_vq_interrupt The resource needed by rproc_vq_interrupt has been released in rproc_stop_subdevices, so flush_work is not safe to be called in imx_dsp_rproc_stop.
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
NVD-CWE-noinfo

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: cgroup: Avoid iteration of dying tasks with zero refcount The commit 260fbcb92bbea ("cgroup: Move dying_tasks cleanup from cgroup_task_release() to cgroup_task_free()") extended the lifetime of tasks on the dying_tasks list. The iterators have provision to go through dying_tasks because of dying threadgroup leaders or explicit CSS_TASK_ITER_WITH_DEAD, however, it was expected that such tasks can obtain a new reference (that is possible before cgroup_task_release()/put_task_struct_rcu_user()). The tasks after cgroup_task_release() and before cgroup_task_free() are subject to race when they may or may not have ->usage count > 0. The race window is between css_task_iter_next() invocations when css_set_lock is released and we may arrive at a new ->task_pos. The iterator should not attempt to resurrect tasks whose ->usage count dropped to zero. (When that happens, __put_task_struct_rcu_cb() is already imminent and the returned task_struct would could be used after free.) As for the fix, we cannot simply check the signal->live count of a task on the dying list because that won't distinguish regular zombies waiting to be reaped from RCU remnant tasks that are going to be free'd. Therefore add an extra check to rule out ->usage==0 tasks from any iteration. The repeat: loop in css_task_iter_advance() doesn't consider ->usage count, so add a new loop to css_task_iter_next() to skip de-used tasks on the dying_list. Rough illustration of the possible race R (reader of cgroup.procs) T (thread) L (group leader) --------------------------------- -------------------------------- -------------------------------- L exits, signal->live > 0 cgroup_task_dead(L) css_set_skip_task_iters() // skips only cset->tasks list_add_tail(&L->cg_list, &cset->dying_tasks) css_task_iter_next() take css_set_lock css_task_iter_advance() leader && signal->live != 0 => it->task_pos = &L->cg_list release css_set_lock T exits --signal->live == 0 cgroup_task_dead(T) // css_set_lock release_task(T) cgroup_task_release(T) release_task(L) // zap_leader cgroup_task_release(L) put_task_struct_rcu_user(L) ...RCU... put_task_struct(L) L->usage = 0 /* L still on dying_tasks */ ...RCU... __put_task_struct(L) css_task_iter_next() // another iteration take css_set_lock it->task_pos = &L->cg_list get_task_struct(L) => addition on 0 drop css_set_lock cgroup_task_free(L) css_set_skip_task_iters() // dying skip comes too late free_task(L) cgroup_procs_show() task_pid_vnr(L)•CVE-2026-98163