CVE-2025-38649

Published Aug 22, 2025

Last updated a year ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: arm64: dts: qcom: qcs615: fix a crash issue caused by infinite loop for Coresight An infinite loop has been created by the Coresight devices. When only a source device is enabled, the coresight_find_activated_sysfs_sink function is recursively invoked in an attempt to locate an active sink device, ultimately leading to a stack overflow and system crash. Therefore, disable the replicator1 to break the infinite loop and prevent a potential stack overflow. replicator1_out -> funnel_swao_in6 -> tmc_etf_swao_in -> tmc_etf_swao_out | | replicator1_in replicator_swao_in | | replicator0_out1 replicator_swao_out0 | | replicator0_in funnel_in1_in3 | | tmc_etf_out <- tmc_etf_in <- funnel_merg_out <- funnel_merg_in1 <- funnel_in1_out [call trace] dump_backtrace+0x9c/0x128 show_stack+0x20/0x38 dump_stack_lvl+0x48/0x60 dump_stack+0x18/0x28 panic+0x340/0x3b0 nmi_panic+0x94/0xa0 panic_bad_stack+0x114/0x138 handle_bad_stack+0x34/0xb8 __bad_stack+0x78/0x80 coresight_find_activated_sysfs_sink+0x28/0xa0 [coresight] coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight] coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight] coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight] coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight] ... coresight_find_activated_sysfs_sink+0x5c/0xa0 [coresight] coresight_enable_sysfs+0x80/0x2a0 [coresight] side effect after the change: Only trace data originating from AOSS can reach the ETF_SWAO and EUD sinks.
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-835

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