CVE-2022-49937

Published Jun 18, 2025

Last updated a year ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: media: mceusb: Use new usb_control_msg_*() routines Automatic kernel fuzzing led to a WARN about invalid pipe direction in the mceusb driver: ------------[ cut here ]------------ usb 6-1: BOGUS control dir, pipe 80000380 doesn't match bRequestType 40 WARNING: CPU: 0 PID: 2465 at drivers/usb/core/urb.c:410 usb_submit_urb+0x1326/0x1820 drivers/usb/core/urb.c:410 Modules linked in: CPU: 0 PID: 2465 Comm: kworker/0:2 Not tainted 5.19.0-rc4-00208-g69cb6c6556ad #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: usb_hub_wq hub_event RIP: 0010:usb_submit_urb+0x1326/0x1820 drivers/usb/core/urb.c:410 Code: 7c 24 40 e8 ac 23 91 fd 48 8b 7c 24 40 e8 b2 70 1b ff 45 89 e8 44 89 f1 4c 89 e2 48 89 c6 48 c7 c7 a0 30 a9 86 e8 48 07 11 02 <0f> 0b e9 1c f0 ff ff e8 7e 23 91 fd 0f b6 1d 63 22 83 05 31 ff 41 RSP: 0018:ffffc900032becf0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff8881100f3058 RCX: 0000000000000000 RDX: ffffc90004961000 RSI: ffff888114c6d580 RDI: fffff52000657d90 RBP: ffff888105ad90f0 R08: ffffffff812c3638 R09: 0000000000000000 R10: 0000000000000005 R11: ffffed1023504ef1 R12: ffff888105ad9000 R13: 0000000000000040 R14: 0000000080000380 R15: ffff88810ba96500 FS: 0000000000000000(0000) GS:ffff88811a800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe810bda58 CR3: 000000010b720000 CR4: 0000000000350ef0 Call Trace: <TASK> usb_start_wait_urb+0x101/0x4c0 drivers/usb/core/message.c:58 usb_internal_control_msg drivers/usb/core/message.c:102 [inline] usb_control_msg+0x31c/0x4a0 drivers/usb/core/message.c:153 mceusb_gen1_init drivers/media/rc/mceusb.c:1431 [inline] mceusb_dev_probe+0x258e/0x33f0 drivers/media/rc/mceusb.c:1807 The reason for the warning is clear enough; the driver sends an unusual read request on endpoint 0 but does not set the USB_DIR_IN bit in the bRequestType field. More importantly, the whole situation can be avoided and the driver simplified by converting it over to the relatively new usb_control_msg_recv() and usb_control_msg_send() routines. That's what this fix does.
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
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