CVE-2025-38153

Published Jul 3, 2025

Last updated 10 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: net: usb: aqc111: fix error handling of usbnet read calls Syzkaller, courtesy of syzbot, identified an error (see report [1]) in aqc111 driver, caused by incomplete sanitation of usb read calls' results. This problem is quite similar to the one fixed in commit 920a9fa27e78 ("net: asix: add proper error handling of usb read errors"). For instance, usbnet_read_cmd() may read fewer than 'size' bytes, even if the caller expected the full amount, and aqc111_read_cmd() will not check its result properly. As [1] shows, this may lead to MAC address in aqc111_bind() being only partly initialized, triggering KMSAN warnings. Fix the issue by verifying that the number of bytes read is as expected and not less. [1] Partial syzbot report: BUG: KMSAN: uninit-value in is_valid_ether_addr include/linux/etherdevice.h:208 [inline] BUG: KMSAN: uninit-value in usbnet_probe+0x2e57/0x4390 drivers/net/usb/usbnet.c:1830 is_valid_ether_addr include/linux/etherdevice.h:208 [inline] usbnet_probe+0x2e57/0x4390 drivers/net/usb/usbnet.c:1830 usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x4d1/0xd90 drivers/base/dd.c:658 __driver_probe_device+0x268/0x380 drivers/base/dd.c:800 ... Uninit was stored to memory at: dev_addr_mod+0xb0/0x550 net/core/dev_addr_lists.c:582 __dev_addr_set include/linux/netdevice.h:4874 [inline] eth_hw_addr_set include/linux/etherdevice.h:325 [inline] aqc111_bind+0x35f/0x1150 drivers/net/usb/aqc111.c:717 usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772 usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396 ... Uninit was stored to memory at: ether_addr_copy include/linux/etherdevice.h:305 [inline] aqc111_read_perm_mac drivers/net/usb/aqc111.c:663 [inline] aqc111_bind+0x794/0x1150 drivers/net/usb/aqc111.c:713 usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772 usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] ... Local variable buf.i created at: aqc111_read_perm_mac drivers/net/usb/aqc111.c:656 [inline] aqc111_bind+0x221/0x1150 drivers/net/usb/aqc111.c:713 usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel, debian_linux

Risk scores

CVSS 3.1

Type
Primary
Base score
7.1
Impact score
5.2
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Severity
HIGH

Weaknesses

nvd@nist.gov
CWE-125

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