Linux KernelOperating system · Linux
CVE-2024-42149
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: fs: don't misleadingly warn during thaw operations The block device may have been frozen before it was claimed by a filesystem. Concurrently another process might try to mount that frozen block device and has temporarily claimed the block device for that purpose causing a concurrent fs_bdev_thaw() to end up here. The mounter is already about to abort mounting because they still saw an elevanted bdev->bd_fsfreeze_count so get_bdev_super() will return NULL in that case. For example, P1 calls dm_suspend() which calls into bdev_freeze() before the block device has been claimed by the filesystem. This brings bdev->bd_fsfreeze_count to 1 and no call into fs_bdev_freeze() is required. Now P2 tries to mount that frozen block device. It claims it and checks bdev->bd_fsfreeze_count. As it's elevated it aborts mounting. In the meantime P3 called dm_resume(). P3 sees that the block device is already claimed by a filesystem and calls into fs_bdev_thaw(). P3 takes a passive reference and realizes that the filesystem isn't ready yet. P3 puts itself to sleep to wait for the filesystem to become ready. P2 now puts the last active reference to the filesystem and marks it as dying. P3 gets woken, sees that the filesystem is dying and get_bdev_super() fails.
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
>= 6.8, < 6.9.9= 6.10CVSS 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 · scoped6.9.9
Linux Kernel 6.9.9 or later (for 6.8-6.9.x range); Linux Kernel 6.10.1 or later (for 6.10)
- 1. Identify the current kernel version using 'uname -r' or 'cat /proc/version'
- 2. For kernels 6.8.x through 6.9.8: Upgrade to kernel version 6.9.9 or later
- 3. For kernel 6.10: Upgrade to kernel version 6.10.1 or later, or to the next stable release that includes the fix
- 4. After upgrading, verify the fix is present by checking the kernel version matches the fixed release
- 5. Reboot the system to load 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-2024-42149 — 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-2024-42149 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