CVE-2026-64187

Public on 2026-07-20
Modified on 2026-07-24
Description
In the Linux kernel, the following vulnerability has been resolved:

xfs: fail recovery on a committed log item with no regions

If the first op of a transaction is a bare transaction header
(len == sizeof(struct xfs_trans_header)), xlog_recover_add_to_trans()
adds an item but no region, leaving it on r_itemq with ri_cnt == 0 and
ri_buf == NULL.

The header can be split across op records, so later ops may still add
regions; the item is only invalid if the transaction commits with none.
The runtime commit path never emits such a transaction, so this only
happens on a crafted log. It came from an AI-assisted code audit of the
recovery parser.

xlog_recover_reorder_trans() calls ITEM_TYPE() on the item, which reads
*(unsigned short *)item->ri_buf[0].iov_base and faults on the NULL
ri_buf. Reject it there, before the commit handlers that also read
ri_buf[0].

KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
RIP: 0010:xlog_recover_reorder_trans (fs/xfs/xfs_log_recover.c:1836)
xlog_recover_commit_trans (fs/xfs/xfs_log_recover.c:2043)
xlog_recover_process_data (fs/xfs/xfs_log_recover.c:2501)
xlog_do_recovery_pass (fs/xfs/xfs_log_recover.c:3244)
xlog_recover (fs/xfs/xfs_log_recover.c:3493)
xfs_log_mount (fs/xfs/xfs_log.c:618)
xfs_mountfs (fs/xfs/xfs_mount.c:1034)
xfs_fs_fill_super (fs/xfs/xfs_super.c:1938)
vfs_get_tree (fs/super.c:1695)
path_mount (fs/namespace.c:4161)
__x64_sys_mount (fs/namespace.c:4367)
Severity
Medium severity
Medium
See what this means
CVSS v3 Base Score
5.5
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Core kernel Pending Fix
Amazon Linux 2 - Kernel-5.10 Extra kernel Pending Fix
Amazon Linux 2 - Kernel-5.15 Extra kernel Pending Fix
Amazon Linux 2 - Kernel-5.4 Extra kernel Pending Fix
Amazon Linux 2023 kernel Pending Fix
Amazon Linux 2023 kernel6.12 Pending Fix
Amazon Linux 2023 kernel6.18 Pending Fix

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H