Description

In the Linux kernel, the following vulnerability has been resolved:

jbd2: stop waiting for space when jbd2_cleanup_journal_tail() returns error

In __jbd2_log_wait_for_space(), we might call jbd2_cleanup_journal_tail()
to recover some journal space. But if an error occurs while executing
jbd2_cleanup_journal_tail() (e.g., an EIO), we don't stop waiting for free
space right away, we try other branches, and if j_committing_transaction
is NULL (i.e., the tid is 0), we will get the following complain:

============================================
JBD2: I/O error when updating journal superblock for sdd-8.
__jbd2_log_wait_for_space: needed 256 blocks and only had 217 space available
__jbd2_log_wait_for_space: no way to get more journal space in sdd-8
------------[ cut here ]------------
WARNING: CPU: 2 PID: 139804 at fs/jbd2/checkpoint.c:109 __jbd2_log_wait_for_space+0x251/0x2e0
Modules linked in:
CPU: 2 PID: 139804 Comm: kworker/u8:3 Not tainted 6.6.0+ #1
RIP: 0010:__jbd2_log_wait_for_space+0x251/0x2e0
Call Trace:

add_transaction_credits+0x5d1/0x5e0
start_this_handle+0x1ef/0x6a0
jbd2__journal_start+0x18b/0x340
ext4_dirty_inode+0x5d/0xb0
__mark_inode_dirty+0xe4/0x5d0
generic_update_time+0x60/0x70
[...]
============================================

So only if jbd2_cleanup_journal_tail() returns 1, i.e., there is nothing to
clean up at the moment, continue to try to reclaim free space in other ways.

Note that this fix relies on commit 6f6a6fda2945 ("jbd2: fix ocfs2 corr...

Classification

CVE ID: CVE-2024-49959

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.03% (probability of being exploited)

EPSS Percentile: 8.91% (scored less or equal to compared to others)

EPSS Date: 2025-06-02 (when was this score calculated)

Stakeholder-Specific Vulnerability Categorization (SSVC)

SSVC Exploitation: none

SSVC Technical Impact: partial

SSVC Automatable: false

References

https://nvd.nist.gov/vuln/detail/CVE-2024-49959
https://git.kernel.org/stable/c/801a35dfef6996f3d5eaa96a59caf00440d9165e
https://git.kernel.org/stable/c/d5dc65370a746750dbb2f03eabcf86b18db65f32
https://git.kernel.org/stable/c/481e8f18a290e39e04ddb7feb2bb2a2cc3b213ed
https://git.kernel.org/stable/c/ec7f8337c98ad281020ad1f11ba492462d80737a
https://git.kernel.org/stable/c/70bae48377a2c4296fd3caf4caf8f11079111019
https://git.kernel.org/stable/c/1c62dc0d82c62f0dc8fcdc4843208e522acccaf5
https://git.kernel.org/stable/c/3ced0fe6c0eff032733ea8b38778b34707270138
https://git.kernel.org/stable/c/c6bf043b210eac67d35a114e345c4e5585672913
https://git.kernel.org/stable/c/f5cacdc6f2bb2a9bf214469dd7112b43dd2dd68a

Timeline