CVE-2026-63812

f2fs: fix incorrect FI_NO_EXTENT handling in __destroy_extent_node()

Published Jul 19, 2026 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-8726-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8727-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8760-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8726-2 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-8726-3 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8800-1 Linux kernel (NVIDIA BaseOS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8760-2 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8726-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8917-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8918-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9024-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9025-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9026-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9040-1 Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-9066-1 Linux kernel (HWE) vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-665
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
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.
Title f2fs: fix incorrect FI_NO_EXTENT handling in __destroy_extent_node()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 30, 2026, 12:27 PM
Reserved
Jul 19, 2026, 7:54 AM
Status
Analyzed
Published
Jul 19, 2026, 12:16 PM
Modified
Nov 10, 2026, 8:14 PM
Severity
Public date
Jul 19, 2026, 12:00 AM