CVE-2025-39769

Published Sep 11, 2025

Last updated 4 days ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: bnxt_en: Fix lockdep warning during rmmod The commit under the Fixes tag added a netdev_assert_locked() in bnxt_free_ntp_fltrs(). The lock should be held during normal run-time but the assert will be triggered (see below) during bnxt_remove_one() which should not need the lock. The netdev is already unregistered by then. Fix it by calling netdev_assert_locked_or_invisible() which will not assert if the netdev is unregistered. WARNING: CPU: 5 PID: 2241 at ./include/net/netdev_lock.h:17 bnxt_free_ntp_fltrs+0xf8/0x100 [bnxt_en] Modules linked in: rpcrdma rdma_cm iw_cm ib_cm configfs ib_core bnxt_en(-) bridge stp llc x86_pkg_temp_thermal xfs tg3 [last unloaded: bnxt_re] CPU: 5 UID: 0 PID: 2241 Comm: rmmod Tainted: G S W 6.16.0 #2 PREEMPT(voluntary) Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.4.3 01/17/2017 RIP: 0010:bnxt_free_ntp_fltrs+0xf8/0x100 [bnxt_en] Code: 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 8b 47 60 be ff ff ff ff 48 8d b8 28 0c 00 00 e8 d0 cf 41 c3 85 c0 0f 85 2e ff ff ff <0f> 0b e9 27 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffa92082387da0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff9e5b593d8000 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff83dc9a70 RDI: ffffffff83e1a1cf RBP: ffff9e5b593d8c80 R08: 0000000000000000 R09: ffffffff8373a2b3 R10: 000000008100009f R11: 0000000000000001 R12: 0000000000000001 R13: ffffffffc01c4478 R14: dead000000000122 R15: dead000000000100 FS: 00007f3a8a52c740(0000) GS:ffff9e631ad1c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055bb289419c8 CR3: 000000011274e001 CR4: 00000000003706f0 Call Trace: <TASK> bnxt_remove_one+0x57/0x180 [bnxt_en] pci_device_remove+0x39/0xc0 device_release_driver_internal+0xa5/0x130 driver_detach+0x42/0x90 bus_remove_driver+0x61/0xc0 pci_unregister_driver+0x38/0x90 bnxt_exit+0xc/0x7d0 [bnxt_en]
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-667

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