CVE-2025-21633

io_uring/sqpoll: zero sqd->thread on tctx errors

Severity Score

7.1

*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

In the Linux kernel, the following vulnerability has been resolved: io_uring/sqpoll: zero sqd->thread on tctx errors Syzkeller reports: BUG: KASAN: slab-use-after-free in thread_group_cputime+0x409/0x700 kernel/sched/cputime.c:341
Read of size 8 at addr ffff88803578c510 by task syz.2.3223/27552 Call Trace: <TASK> ... kasan_report+0x143/0x180 mm/kasan/report.c:602 thread_group_cputime+0x409/0x700 kernel/sched/cputime.c:341 thread_group_cputime_adjusted+0xa6/0x340 kernel/sched/cputime.c:639 getrusage+0x1000/0x1340 kernel/sys.c:1863 io_uring_show_fdinfo+0xdfe/0x1770 io_uring/fdinfo.c:197 seq_show+0x608/0x770 fs/proc/fd.c:68 ... That's due to sqd->task not being cleared properly in cases where
SQPOLL task tctx setup fails, which can essentially only happen with
fault injection to insert allocation errors.

In the Linux kernel, the following vulnerability has been resolved: io_uring/sqpoll: zero sqd->thread on tctx errors Syzkeller reports: BUG: KASAN: slab-use-after-free in thread_group_cputime+0x409/0x700 kernel/sched/cputime.c:341 Read of size 8 at addr ffff88803578c510 by task syz.2.3223/27552 Call Trace: <TASK> ... kasan_report+0x143/0x180 mm/kasan/report.c:602 thread_group_cputime+0x409/0x700 kernel/sched/cputime.c:341 thread_group_cputime_adjusted+0xa6/0x340 kernel/sched/cputime.c:639 getrusage+0x1000/0x1340 kernel/sys.c:1863 io_uring_show_fdinfo+0xdfe/0x1770 io_uring/fdinfo.c:197 seq_show+0x608/0x770 fs/proc/fd.c:68 ... That's due to sqd->task not being cleared properly in cases where SQPOLL task tctx setup fails, which can essentially only happen with fault injection to insert allocation errors.

*Credits: N/A

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Attack Vector

Local

Attack Complexity

Low

Authentication

None

Confidentiality

Complete

Integrity

None

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2024-12-29 CVE Reserved
2025-01-19 CVE Published
2025-01-20 CVE Updated
2025-01-20 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (3)

URL	Tag	Source
https://git.kernel.org/stable/c/1251d2025c3e1bcf1f17ec0f3c0dfae5e5bbb146	Vuln. Introduced

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/aa7496d668c30ca7421b3bfdcd948ee861a13d17	2025-01-17
https://git.kernel.org/stable/c/4b7cfa8b6c28a9fa22b86894166a1a34f6d630ba	2025-01-10

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 6.9 < 6.12.10 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.9 < 6.12.10"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 6.9 < 6.13 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.9 < 6.13"		en		Affected