CVE-2022-50164

Published Jun 18, 2025

Last updated 3 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mvm: fix double list_add at iwl_mvm_mac_wake_tx_queue After successfull station association, if station queues are disabled for some reason, the related lists are not emptied. So if some new element is added to the list in iwl_mvm_mac_wake_tx_queue, it can match with the old one and produce a BUG like this: [ 46.535263] list_add corruption. prev->next should be next (ffff94c1c318a360), but was 0000000000000000. (prev=ffff94c1d02d3388). [ 46.535283] ------------[ cut here ]------------ [ 46.535284] kernel BUG at lib/list_debug.c:26! [ 46.535290] invalid opcode: 0000 [#1] PREEMPT SMP PTI [ 46.585304] CPU: 0 PID: 623 Comm: wpa_supplicant Not tainted 5.19.0-rc3+ #1 [ 46.592380] Hardware name: Dell Inc. Inspiron 660s/0478VN , BIOS A07 08/24/2012 [ 46.600336] RIP: 0010:__list_add_valid.cold+0x3d/0x3f [ 46.605475] Code: f2 4c 89 c1 48 89 fe 48 c7 c7 c8 40 67 93 e8 20 cc fd ff 0f 0b 48 89 d1 4c 89 c6 4c 89 ca 48 c7 c7 70 40 67 93 e8 09 cc fd ff <0f> 0b 48 89 fe 48 c7 c7 00 41 67 93 e8 f8 cb fd ff 0f 0b 48 89 d1 [ 46.624469] RSP: 0018:ffffb20800ab76d8 EFLAGS: 00010286 [ 46.629854] RAX: 0000000000000075 RBX: ffff94c1c318a0e0 RCX: 0000000000000000 [ 46.637105] RDX: 0000000000000201 RSI: ffffffff9365e100 RDI: 00000000ffffffff [ 46.644356] RBP: ffff94c1c5f43370 R08: 0000000000000075 R09: 3064316334396666 [ 46.651607] R10: 3364323064316334 R11: 39666666663d7665 R12: ffff94c1c5f43388 [ 46.658857] R13: ffff94c1d02d3388 R14: ffff94c1c318a360 R15: ffff94c1cf2289c0 [ 46.666108] FS: 00007f65634ff7c0(0000) GS:ffff94c1da200000(0000) knlGS:0000000000000000 [ 46.674331] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 46.680170] CR2: 00007f7dfe984460 CR3: 000000010e894003 CR4: 00000000000606f0 [ 46.687422] Call Trace: [ 46.689906] <TASK> [ 46.691950] iwl_mvm_mac_wake_tx_queue+0xec/0x15c [iwlmvm] [ 46.697601] ieee80211_queue_skb+0x4b3/0x720 [mac80211] [ 46.702973] ? sta_info_get+0x46/0x60 [mac80211] [ 46.707703] ieee80211_tx+0xad/0x110 [mac80211] [ 46.712355] __ieee80211_tx_skb_tid_band+0x71/0x90 [mac80211] ... In order to avoid this problem, we must also remove the related lists when station queues are disabled.
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
7.8
Impact score
5.9
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity
HIGH

Weaknesses

nvd@nist.gov
CWE-415

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