Linux KernelOperating system · Linux
CVE-2026-64187
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn 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)
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisThe code follows a pointer that is null, crashing the process. An attacker who can reliably trigger it turns the crash into a denial of service. The fix is checking for null before use and handling the failure path gracefully.
General guidance for the null pointer dereference class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Linux KernelOperating system
>= 4.3, < 5.15.212>= 5.16, < 6.1.178>= 6.2, < 6.6.145>= 6.7, < 6.12.96>= 6.13, < 6.18.39>= 6.19, < 7.1.4= 7.2CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped5.15.2126.1.1786.6.145
Kernel version >= 5.15.212, >= 6.1.178, >= 6.6.145, or >= 6.12.96 depending on your branch; or latest stable (6.12.x or newer)
- 1. Identify the current running kernel version using `uname -r`
- 2. Check which kernel branch your current version belongs to (e.g., 5.15.x, 6.1.x, 6.2.x, 6.7.x)
- 3. Upgrade the Linux kernel to the fixed version for your branch: for 5.15.x series use >= 5.15.212, for 6.1.x series use >= 6.1.178, for 6.2-6.6.x series use >= 6.6.145, for 6.7-6.12.x series use >= 6.12.96
- 4. Alternatively, upgrade to the latest stable kernel release (currently 6.12.x or newer) which includes all security fixes
- 5. Reboot the system to load the fixed kernel
- 6. Verify the fix is applied by checking `uname -r` shows the patched version and the system boots without the KASAN null-ptr-deref error
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-64187 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-64187 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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