CVE-2025-38379

Published Jul 25, 2025

Last updated 3 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix warning when reconnecting channel When reconnecting a channel in smb2_reconnect_server(), a dummy tcon is passed down to smb2_reconnect() with ->query_interface uninitialized, so we can't call queue_delayed_work() on it. Fix the following warning by ensuring that we're queueing the delayed worker from correct tcon. WARNING: CPU: 4 PID: 1126 at kernel/workqueue.c:2498 __queue_delayed_work+0x1d2/0x200 Modules linked in: cifs cifs_arc4 nls_ucs2_utils cifs_md4 [last unloaded: cifs] CPU: 4 UID: 0 PID: 1126 Comm: kworker/4:0 Not tainted 6.16.0-rc3 #5 PREEMPT(voluntary) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-4.fc42 04/01/2014 Workqueue: cifsiod smb2_reconnect_server [cifs] RIP: 0010:__queue_delayed_work+0x1d2/0x200 Code: 41 5e 41 5f e9 7f ee ff ff 90 0f 0b 90 e9 5d ff ff ff bf 02 00 00 00 e8 6c f3 07 00 89 c3 eb bd 90 0f 0b 90 e9 57 f> 0b 90 e9 65 fe ff ff 90 0f 0b 90 e9 72 fe ff ff 90 0f 0b 90 e9 RSP: 0018:ffffc900014afad8 EFLAGS: 00010003 RAX: 0000000000000000 RBX: ffff888124d99988 RCX: ffffffff81399cc1 RDX: dffffc0000000000 RSI: ffff888114326e00 RDI: ffff888124d999f0 RBP: 000000000000ea60 R08: 0000000000000001 R09: ffffed10249b3331 R10: ffff888124d9998f R11: 0000000000000004 R12: 0000000000000040 R13: ffff888114326e00 R14: ffff888124d999d8 R15: ffff888114939020 FS: 0000000000000000(0000) GS:ffff88829f7fe000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe7a2b4038 CR3: 0000000120a6f000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> queue_delayed_work_on+0xb4/0xc0 smb2_reconnect+0xb22/0xf50 [cifs] smb2_reconnect_server+0x413/0xd40 [cifs] ? __pfx_smb2_reconnect_server+0x10/0x10 [cifs] ? local_clock_noinstr+0xd/0xd0 ? local_clock+0x15/0x30 ? lock_release+0x29b/0x390 process_one_work+0x4c5/0xa10 ? __pfx_process_one_work+0x10/0x10 ? __list_add_valid_or_report+0x37/0x120 worker_thread+0x2f1/0x5a0 ? __kthread_parkme+0xde/0x100 ? __pfx_worker_thread+0x10/0x10 kthread+0x1fe/0x380 ? kthread+0x10f/0x380 ? __pfx_kthread+0x10/0x10 ? local_clock_noinstr+0xd/0xd0 ? ret_from_fork+0x1b/0x1f0 ? local_clock+0x15/0x30 ? lock_release+0x29b/0x390 ? rcu_is_watching+0x20/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x15b/0x1f0 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> irq event stamp: 1116206 hardirqs last enabled at (1116205): [<ffffffff8143af42>] __up_console_sem+0x52/0x60 hardirqs last disabled at (1116206): [<ffffffff81399f0e>] queue_delayed_work_on+0x6e/0xc0 softirqs last enabled at (1116138): [<ffffffffc04562fd>] __smb_send_rqst+0x42d/0x950 [cifs] softirqs last disabled at (1116136): [<ffffffff823d35e1>] release_sock+0x21/0xf0
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