CVE-2026-63812

HIGH
MEDIUM Priority: 0.01 BB Relevance: 41/100
Published: 2026-07-19 Modified: 2026-10-30 First seen: 2026-10-30 Status: active

Attack Surface

Low Complexity No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Local
AC: Low
PR: Low
UI: None
S: Unchanged
C: High
I: High
A: High

Description

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix incorrect FI_NO_EXTENT handling in __destroy_extent_node() When __destroy_extent_node() sets the inode flag FI_NO_EXTENT, it does not reset the length of the largest extent to 0 and update the inode folio. Since modifications to the extent tree are disallowed afterward, the cached largest extent may become stale. This can trigger the following error in xfstests generic/388: F2FS-fs (dm-0): sanity_check_extent_cache: inode (ino=1761) extent info [220057, 57, 6] is incorrect, run fsck to fix In the f2fs_drop_inode path, __destroy_extent_node() does not need to guarantee that et->node_cnt is 0, because concurrency with writeback is expected in this path, and writeback may update the extent cache. This patch reverts commit ed78aeebef05 ("f2fs: fix node_cnt race between extent node destroy and writeback"), and remove the unnecessary zero check of et->node_cnt.

Affected Software (13)

VendorProductVersion
Linux Linux 42dd1c91f993431d0b399502479d00e6ad1bca71 < 7e4d8f98be63f98856a5176b9188dada6e7ba9ee
Linux Linux ab1eaf9d5c99042f5b0243bf67a06283a4c0757f < 58a5deb220bcac4c73bf58954c0845644c997487
Linux Linux b0e4395870eb3441ddc959f6710b5f6ca61aff26 < 20190e498057997532c7f186d081011f18e0a462
Linux Linux ed78aeebef05212ef7dca93bd931e4eff67c113f < edf12cbeeeabe799bd2ee21fdb5c336cce6fbad7
Linux Linux ed78aeebef05212ef7dca93bd931e4eff67c113f < 1f70ddb28a3c71df124da5fa4040c808116d6bb9
Linux Linux b00e6950da9c0e4986f6e93c875d2b9184bdb220
Linux Linux 0559a0e962aacbb47519e26ee663be04b72dcb92
Linux Linux 6.6.140 < 6.6.144
Linux Linux 6.12.88 < 6.12.95
Linux Linux 6.18.30 < 6.18.38
Linux Linux 6.1.191 < 6.2
Linux Linux 7.0.7 < 7.1
Linux Linux 7.1

Bug Bounty Relevance

41 / 100
✓ Low complexity
✓ No user interaction

CVSS Score

7.8 / 10.0 v3.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploitation Probability

0.13%
Raw Score 0.001260
Percentile 2.3%
Date 2026-11-01

EPSS Trend

2026-11-01
0.00126
2026-10-31
0.00126
2026-10-30
0.00126
2026-10-29
0.00126

Intelligence Sources

mitre ref →
nvd ref →