Linux KernelOperating system · Linux
CVE-2024-26885
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: bpf: Fix DEVMAP_HASH overflow check on 32-bit arches The devmap code allocates a number hash buckets equal to the next power of two of the max_entries value provided when creating the map. When rounding up to the next power of two, the 32-bit variable storing the number of buckets can overflow, and the code checks for overflow by checking if the truncated 32-bit value is equal to 0. However, on 32-bit arches the rounding up itself can overflow mid-way through, because it ends up doing a left-shift of 32 bits on an unsigned long value. If the size of an unsigned long is four bytes, this is undefined behaviour, so there is no guarantee that we'll end up with a nice and tidy 0-value at the end. Syzbot managed to turn this into a crash on arm32 by creating a DEVMAP_HASH with max_entries > 0x80000000 and then trying to update it. Fix this by moving the overflow check to before the rounding up operation.
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 program reads or writes outside the bounds of an allocated buffer, corrupting adjacent memory. With crafted input an attacker can overwrite control data and, with effort, redirect execution to their own code. Remediation ranges from bounds checking and safe library functions to compiler mitigations, usually alongside a careful audit of the surrounding code.
General guidance for the memory buffer bounds error 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
>= 5.4, < 5.10.214>= 5.11, < 5.15.153>= 5.16, < 6.1.83>= 6.2, < 6.6.23>= 6.7, < 6.7.11>= 6.8, < 6.8.2CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 · scoped5.10.2145.15.1536.1.83
Upgrade to kernel >= 5.10.214, >= 5.15.153, >= 6.1.83, or >= 6.6.23 (depending on your current branch)
- 1. Check the currently running kernel version using 'uname -r'
- 2. Identify which version branch your kernel is on (e.g., 5.10.x, 5.15.x, 6.1.x, 6.2.x)
- 3. Upgrade to a fixed kernel version based on your current branch: For 5.10.x: upgrade to >= 5.10.214; For 5.15.x: upgrade to >= 5.15.153; For 6.1.x: upgrade to >= 6.1.83; For 6.2.x: upgrade to >= 6.6.23
- 4. On 32-bit ARM systems specifically, ensure max_entries for DEVMAP_HASH BPF maps does not exceed 0x80000000 as a configuration mitigation until patched
- 5. Reboot into the updated kernel
- 6. Verify the fix by checking the kernel version matches or exceeds the fixed versions above
Generated from the published advisory — verify against the referenced sources before acting.
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Free · runs locallyCheck whether your project pulls in CVE-2024-26885 — 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-2024-26885 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
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- Version or environment caveats, and links to real fixes
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