CVE-2025-21633

Published Jan 19, 2025

Last updated a year ago

CVSS high 7.8

Overview

Description
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.
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Secondary
Base score
7.8
Impact score
5.9
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity
HIGH

Weaknesses

134c704f-9b21-4f2e-91b3-4a467353bcc0
CWE-416

Social media

Hype score
Not currently trending

  1. (CVE-2025-21655)[io_uring/eventfd]ensure io_eventfd_signal() defers another RCU period https://t.co/n5aMJLsSlw @tehjh (CVE-2025-21633)[io_uring/sqpoll]slab-UAF in thread_group_cputime https://t.co/KjTe9uu0WG https://t.co/pNP1K7yiu2

    @xvonfers

    20 Jan 2025

    2275 Impressions

    7 Retweets

    37 Likes

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  2. CVE-2025-21633 Linux Kernel io_uring Use-After-Free Vulnerability Resolved https://t.co/3ZXgJ5RS5U

    @VulmonFeeds

    19 Jan 2025

    52 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  3. CVE-2025-21633 In the Linux kernel, the following vulnerability has been resolved: io_uring/sqpoll: zero sqd-&gt;thread on tctx errors Syzkeller reports: BUG: KASAN: slab-use-after-… https://t.co/sQsPCZAynW

    @CVEnew

    19 Jan 2025

    251 Impressions

    0 Retweets

    0 Likes

    1 Bookmark

    0 Replies

    0 Quotes

Configurations

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References

Sources include official advisories and independent security research.