CVE-2023-53565

Published Oct 4, 2025

Last updated 7 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: Check for probe() id argument being NULL The probe() id argument may be NULL in 2 scenarios: 1. brcmf_pcie_pm_leave_D3() calling brcmf_pcie_probe() to reprobe the device. 2. If a user tries to manually bind the driver from sysfs then the sdio / pcie / usb probe() function gets called with NULL as id argument. 1. Is being hit by users causing the following oops on resume and causing wifi to stop working: BUG: kernel NULL pointer dereference, address: 0000000000000018 <snip> Hardware name: Dell Inc. XPS 13 9350/0PWNCR, BIDS 1.13.0 02/10/2020 Workgueue: events_unbound async_run_entry_fn RIP: 0010:brcmf_pcie_probe+Ox16b/0x7a0 [brcmfmac] <snip> Call Trace: <TASK> brcmf_pcie_pm_leave_D3+0xc5/8x1a0 [brcmfmac be3b4cefca451e190fa35be8f00db1bbec293887] ? pci_pm_resume+0x5b/0xf0 ? pci_legacy_resume+0x80/0x80 dpm_run_callback+0x47/0x150 device_resume+0xa2/0x1f0 async_resume+0x1d/0x30 <snip> Fix this by checking for id being NULL. In the PCI and USB cases try a manual lookup of the id so that manually binding the driver through sysfs and more importantly brcmf_pcie_probe() on resume will work. For the SDIO case there is no helper to do a manual sdio_device_id lookup, so just directly error out on a NULL id there.
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-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