CVE-2025-38011

Published Jun 18, 2025

Last updated 7 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: csa unmap use uninterruptible lock After process exit to unmap csa and free GPU vm, if signal is accepted and then waiting to take vm lock is interrupted and return, it causes memory leaking and below warning backtrace. Change to use uninterruptible wait lock fix the issue. WARNING: CPU: 69 PID: 167800 at amd/amdgpu/amdgpu_kms.c:1525 amdgpu_driver_postclose_kms+0x294/0x2a0 [amdgpu] Call Trace: <TASK> drm_file_free.part.0+0x1da/0x230 [drm] drm_close_helper.isra.0+0x65/0x70 [drm] drm_release+0x6a/0x120 [drm] amdgpu_drm_release+0x51/0x60 [amdgpu] __fput+0x9f/0x280 ____fput+0xe/0x20 task_work_run+0x67/0xa0 do_exit+0x217/0x3c0 do_group_exit+0x3b/0xb0 get_signal+0x14a/0x8d0 arch_do_signal_or_restart+0xde/0x100 exit_to_user_mode_loop+0xc1/0x1a0 exit_to_user_mode_prepare+0xf4/0x100 syscall_exit_to_user_mode+0x17/0x40 do_syscall_64+0x69/0xc0 (cherry picked from commit 7dbbfb3c171a6f63b01165958629c9c26abf38ab)
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
CWE-401

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