Release Date: | 2025-02-27 | |
Impact: | Moderate | What is this? |
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix use-after-free when attempting to join an aborted transaction
When we are trying to join the current transaction and if it's aborted,
we read its 'aborted' field after unlocking fs_info->trans_lock and
without holding any extra reference count on it. This means that a
concurrent task that is aborting the transaction may free the transaction
before we read its 'aborted' field, leading to a use-after-free.
Fix this by reading the 'aborted' field while holding fs_info->trans_lock
since any freeing task must first acquire that lock and set
fs_info->running_transaction to NULL before freeing the transaction.
This was reported by syzbot and Dmitry with the following stack traces
from KASAN:
==================================================================
BUG: KASAN: slab-use-after-free in join_transaction+0xd9b/0xda0 fs/btrfs/transaction.c:278
Read of size 4 at addr ffff888011839024 by task kworker/u4:9/1128
CPU: 0 UID: 0 PID: 1128 Comm: kworker/u4:9 Not tainted 6.13.0-rc7-syzkaller-00019-gc45323b7560e #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: events_unbound btrfs_async_reclaim_data_space
Call Trace:
See more information about CVE-2025-21753 from MITRE CVE dictionary and NIST NVD
NOTE: The following CVSS metrics and score provided are preliminary and subject to review.
Base Score: | 7.1 |
Vector String: | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H |
Version: | 3.1 |
Attack Vector: | Local |
Attack Complexity: | Low |
Privileges Required: | Low |
User Interaction: | None |
Scope: | Unchanged |
Confidentiality Impact: | High |
Integrity Impact: | None |
Availability Impact: | High |
Platform | Errata | Release Date |
Oracle Linux version 10 (kernel-uek) | ELSA-2025-20480 | 2025-07-17 |
Oracle Linux version 10 (kernel-uek) | ELSA-2025-20530 | 2025-08-18 |
Oracle Linux version 9 (kernel-uek) | ELSA-2025-20480 | 2025-07-17 |
Oracle Linux version 9 (kernel-uek) | ELSA-2025-20530 | 2025-08-18 |
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