CVE-2025-22032

Published Apr 16, 2025

Last updated a year ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7921: fix kernel panic due to null pointer dereference Address a kernel panic caused by a null pointer dereference in the `mt792x_rx_get_wcid` function. The issue arises because the `deflink` structure is not properly initialized with the `sta` context. This patch ensures that the `deflink` structure is correctly linked to the `sta` context, preventing the null pointer dereference. BUG: kernel NULL pointer dereference, address: 0000000000000400 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 0 UID: 0 PID: 470 Comm: mt76-usb-rx phy Not tainted 6.12.13-gentoo-dist #1 Hardware name: /AMD HUDSON-M1, BIOS 4.6.4 11/15/2011 RIP: 0010:mt792x_rx_get_wcid+0x48/0x140 [mt792x_lib] RSP: 0018:ffffa147c055fd98 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff8e9ecb652000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8e9ecb652000 RBP: 0000000000000685 R08: ffff8e9ec6570000 R09: 0000000000000000 R10: ffff8e9ecd2ca000 R11: ffff8e9f22a217c0 R12: 0000000038010119 R13: 0000000080843801 R14: ffff8e9ec6570000 R15: ffff8e9ecb652000 FS: 0000000000000000(0000) GS:ffff8e9f22a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000400 CR3: 000000000d2ea000 CR4: 00000000000006f0 Call Trace: <TASK> ? __die_body.cold+0x19/0x27 ? page_fault_oops+0x15a/0x2f0 ? search_module_extables+0x19/0x60 ? search_bpf_extables+0x5f/0x80 ? exc_page_fault+0x7e/0x180 ? asm_exc_page_fault+0x26/0x30 ? mt792x_rx_get_wcid+0x48/0x140 [mt792x_lib] mt7921_queue_rx_skb+0x1c6/0xaa0 [mt7921_common] mt76u_alloc_queues+0x784/0x810 [mt76_usb] ? __pfx___mt76_worker_fn+0x10/0x10 [mt76] __mt76_worker_fn+0x4f/0x80 [mt76] kthread+0xd2/0x100 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> ---[ end trace 0000000000000000 ]---
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
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
CWE-476
134c704f-9b21-4f2e-91b3-4a467353bcc0
CWE-476

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