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

btrfs: zoned: do not flag ZEROOUT on non-dirty extent buffer

Btrfs clears the content of an extent buffer marked as
EXTENT_BUFFER_ZONED_ZEROOUT before the bio submission. This mechanism is
introduced to prevent a write hole of an extent buffer, which is once
allocated, marked dirty, but turns out unnecessary and cleaned up within
one transaction operation.

Currently, btrfs_clear_buffer_dirty() marks the extent buffer as
EXTENT_BUFFER_ZONED_ZEROOUT, and skips the entry function. If this call
happens while the buffer is under IO (with the WRITEBACK flag set,
without the DIRTY flag), we can add the ZEROOUT flag and clear the
buffer's content just before a bio submission. As a result:

1) it can lead to adding faulty delayed reference item which leads to a
FS corrupted (EUCLEAN) error, and

2) it writes out cleared tree node on disk

The former issue is previously discussed in [1]. The corruption happens
when it runs a delayed reference update. So, on-disk data is safe.

[1] https://lore.kernel.org/linux-btrfs/3f4f2a0ff1a6c818050434288925bdcf3cd719e5.1709124777.git.naohiro.aota@wdc.com/

The latter one can reach on-disk data. But, as that node is already
processed by btrfs_clear_buffer_dirty(), that will be invalidated in the
next transaction commit anyway. So, the chance of hitting the corruption
is relatively small.

Anyway, we should skip flagging ZEROOUT on a non-DIRTY extent buffer, to
keep the content under IO intact.
History

Sun, 04 May 2025 10:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T09:10:51.723Z

Reserved: 2024-05-17T13:50:33.159Z

Link: CVE-2024-36027

cve-icon Vulnrichment

Updated: 2024-08-02T03:30:12.531Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-05-30T16:15:11.070

Modified: 2024-11-21T09:21:28.023

Link: CVE-2024-36027

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-05-30T00:00:00Z

Links: CVE-2024-36027 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-07-12T15:42:32Z