CVE-2025-38647

Published Aug 22, 2025

Last updated 10 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: wifi: rtw89: sar: drop lockdep assertion in rtw89_set_sar_from_acpi The following assertion is triggered on the rtw89 driver startup. It looks meaningless to hold wiphy lock on the early init stage so drop the assertion. WARNING: CPU: 7 PID: 629 at drivers/net/wireless/realtek/rtw89/sar.c:502 rtw89_set_sar_from_acpi+0x365/0x4d0 [rtw89_core] CPU: 7 UID: 0 PID: 629 Comm: (udev-worker) Not tainted 6.15.0+ #29 PREEMPT(lazy) Hardware name: LENOVO 21D0/LNVNB161216, BIOS J6CN50WW 09/27/2024 RIP: 0010:rtw89_set_sar_from_acpi+0x365/0x4d0 [rtw89_core] Call Trace: <TASK> rtw89_sar_init+0x68/0x2c0 [rtw89_core] rtw89_core_init+0x188e/0x1e50 [rtw89_core] rtw89_pci_probe+0x530/0xb50 [rtw89_pci] local_pci_probe+0xd9/0x190 pci_call_probe+0x183/0x540 pci_device_probe+0x171/0x2c0 really_probe+0x1e1/0x890 __driver_probe_device+0x18c/0x390 driver_probe_device+0x4a/0x120 __driver_attach+0x1a0/0x530 bus_for_each_dev+0x10b/0x190 bus_add_driver+0x2eb/0x540 driver_register+0x1a3/0x3a0 do_one_initcall+0xd5/0x450 do_init_module+0x2cc/0x8f0 init_module_from_file+0xe1/0x150 idempotent_init_module+0x226/0x760 __x64_sys_finit_module+0xcd/0x150 do_syscall_64+0x94/0x380 entry_SYSCALL_64_after_hwframe+0x76/0x7e Found by Linux Verification Center (linuxtesting.org).
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