Linux KernelOperating system · Linux
CVE-2026-64164
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: btrfs: tracepoints: fix sleep while in atomic context in btrfs_sync_file() The trace event btrfs_sync_file() is called in an atomic context (all trace events are) and its call to dput(), which is needed due to the call to dget_parent(), can sleep, triggering a kernel splat. This can be reproduced by enabling the trace event and running btrfs/056 from fstests for example. The splat shown in dmesg is the following: [53.919] BUG: sleeping function called from invalid context at fs/dcache.c:970 [53.947] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 32773, name: xfs_io [53.988] preempt_count: 2, expected: 0 [53.967] RCU nest depth: 0, expected: 0 [53.943] Preemption disabled at: [53.944] [<0000000000000000>] 0x0 [54.078] CPU: 0 UID: 0 PID: 32773 Comm: xfs_io Tainted: G W 7.1.0-rc1-btrfs-next-232+ #1 PREEMPT(full) [54.070] Tainted: [W]=WARN [54.071] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014 [54.072] Call Trace: [54.074] <TASK> [54.076] dump_stack_lvl+0x56/0x80 [54.079] __might_resched.cold+0xd6/0x10f [54.072] dput.part.0+0x24/0x110 [54.078] trace_event_raw_event_btrfs_sync_file+0x75/0x140 [btrfs] [54.089] btrfs_sync_file+0x1ed/0x530 [btrfs] [54.087] ? __handle_mm_fault+0x8ae/0xed0 [54.089] btrfs_do_write_iter+0x172/0x210 [btrfs] [54.091] vfs_write+0x21f/0x450 [54.094] __x64_sys_pwrite64+0x8d/0xc0 [54.096] ? do_user_addr_fault+0x20c/0x670 [54.099] do_syscall_64+0x60/0xf20 [54.092] ? clear_bhb_loop+0x60/0xb0 [54.094] entry_SYSCALL_64_after_hwframe+0x76/0x7e So stop using dget_parent() and dput() and access the parent dentry directly as dentry->d_parent. This is also what ext4 is doing in its equivalent trace event ext4_sync_file_enter().
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
>= 6.6.136, < 6.6.142>= 6.12.83, < 6.12.92>= 6.18.24, < 6.18.34>= 6.19.14, < 7.0>= 7.0.1, < 7.0.11= 7.0= 7.1CVSS 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 · scoped6.6.1426.12.926.18.34
Linux Kernel 6.6.142 / 6.12.92 / 6.18.34 / 7.0 (depending on your branch)
- Identify the currently running kernel version using 'uname -r'
- Determine which version branch your kernel belongs to (e.g., 6.6.x, 6.12.x, 6.18.x, or 6.19.x)
- For 6.6.x branches: upgrade to kernel version 6.6.142 or later
- For 6.12.x branches: upgrade to kernel version 6.12.92 or later
- For 6.18.x branches: upgrade to kernel version 6.18.34 or later
- For 6.19.x branches: upgrade to kernel version 7.0 or later
- Reboot into the new kernel
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-2026-64164 — 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-2026-64164 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
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data