CVE-2024-58238

Published Aug 9, 2025

Last updated 8 days ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btnxpuart: Resolve TX timeout error in power save stress test This fixes the tx timeout issue seen while running a stress test on btnxpuart for couple of hours, such that the interval between two HCI commands coincide with the power save timeout value of 2 seconds. Test procedure using bash script: <load btnxpuart.ko> hciconfig hci0 up //Enable Power Save feature hcitool -i hci0 cmd 3f 23 02 00 00 while (true) do hciconfig hci0 leadv sleep 2 hciconfig hci0 noleadv sleep 2 done Error log, after adding few more debug prints: Bluetooth: btnxpuart_queue_skb(): 01 0A 20 01 00 Bluetooth: hci0: Set UART break: on, status=0 Bluetooth: hci0: btnxpuart_tx_wakeup() tx_work scheduled Bluetooth: hci0: btnxpuart_tx_work() dequeue: 01 0A 20 01 00 Can't set advertise mode on hci0: Connection timed out (110) Bluetooth: hci0: command 0x200a tx timeout When the power save mechanism turns on UART break, and btnxpuart_tx_work() is scheduled simultaneously, psdata->ps_state is read as PS_STATE_AWAKE, which prevents the psdata->work from being scheduled, which is responsible to turn OFF UART break. This issue is fixed by adding a ps_lock mutex around UART break on/off as well as around ps_state read/write. btnxpuart_tx_wakeup() will now read updated ps_state value. If ps_state is PS_STATE_SLEEP, it will first schedule psdata->work, and then it will reschedule itself once UART break has been turned off and ps_state is PS_STATE_AWAKE. Tested above script for 50,000 iterations and TX timeout error was not observed anymore.
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
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