CVE-2024-26883

HIGH
Published Apr 17, 2024 Modified May 12, 2026 CWE-119

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix stackmap overflow check on 32-bit arches The stackmap code relies on roundup_pow_of_two() to compute the number of hash buckets, and contains an overflow check by checking if the resulting value is 0. However, on 32-bit arches, the roundup code itself can overflow by doing a 32-bit left-shift of an unsigned long value, which is undefined behaviour, so it is not guaranteed to truncate neatly. This was triggered by syzbot on the DEVMAP_HASH type, which contains the same check, copied from the hashtab code. The commit in the fixes tag actually attempted to fix this, but the fix did not account for the UB, so the fix only works on CPUs where an overflow does result in a neat truncation to zero, which is not guaranteed. Checking the value before rounding does not have this problem.

Is your site exposed to CVE-2024-26883?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

7.8
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-119 Buffer Overflow

Affected Products

Vendor Product
debian debian_linux
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel

References

Advisories & Patches

https://git.kernel.org/stable/c/0971126c8164abe2004b8536b49690a0d6005b0a https://git.kernel.org/stable/c/15641007df0f0d35fa28742b25c2a7db9dcd6895 https://git.kernel.org/stable/c/21e5fa4688e1a4d3db6b72216231b24232f75c1d https://git.kernel.org/stable/c/43f798b9036491fb014b55dd61c4c5c3193267d0 https://git.kernel.org/stable/c/7070b274c7866a4c5036f8d54fcaf315c64ac33a https://git.kernel.org/stable/c/7a4b21250bf79eef26543d35bd390448646c536b https://git.kernel.org/stable/c/ca1f06e72dec41ae4f76e7b1a8a97265447b46ae https://git.kernel.org/stable/c/d0e214acc59145ce25113f617311aa79dda39cb3 https://git.kernel.org/stable/c/f06899582ccee09bd85d0696290e3eaca9aa042d https://git.kernel.org/stable/c/0971126c8164abe2004b8536b49690a0d6005b0a https://git.kernel.org/stable/c/15641007df0f0d35fa28742b25c2a7db9dcd6895 https://git.kernel.org/stable/c/21e5fa4688e1a4d3db6b72216231b24232f75c1d https://git.kernel.org/stable/c/43f798b9036491fb014b55dd61c4c5c3193267d0 https://git.kernel.org/stable/c/7070b274c7866a4c5036f8d54fcaf315c64ac33a https://git.kernel.org/stable/c/7a4b21250bf79eef26543d35bd390448646c536b https://git.kernel.org/stable/c/ca1f06e72dec41ae4f76e7b1a8a97265447b46ae https://git.kernel.org/stable/c/d0e214acc59145ce25113f617311aa79dda39cb3 https://git.kernel.org/stable/c/f06899582ccee09bd85d0696290e3eaca9aa042d

Frequently Asked Questions

What is CVE-2024-26883? +
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix stackmap overflow check on 32-bit arches The stackmap code relies on roundup_pow_of_two() to compute the number of hash buckets, and contains an overflow check by checking if the resulting value is 0. However, on 32-bit arches, the roundup code itself can overflow by doing a 32-bit left-shift of an unsigned long value, which is undefined behaviour, so it is not guaranteed to truncate neatly. This was triggered by syzbot on the DEVMAP_HASH type, which contains the same check, copied from the hashtab code. The commit in the fixes tag actually attempted to fix this, but the fix did not account for the UB, so the fix only works on CPUs where an overflow does result in a neat truncation to zero, which is not guaranteed. Checking the value before rounding does not have this problem. It has a CVSS v3.1 base score of 7.8 (HIGH).
How severe is CVE-2024-26883? +
CVE-2024-26883 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
What products are affected by CVE-2024-26883? +
CVE-2024-26883 affects products from debian, linux, specifically: debian_linux, linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2024-26883? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2024-11139

CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability exists that could allow local attackers to …
CVE-2025-1866

Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in warmcat libwebsockets allows Pointer Manipulation, potentially leading …
CVE-2025-2401

Buffer overflow vulnerability in Immunity Debugger affecting version 1.85, its exploitation could allow a local attacker to execute arbitrary code, …
CVE-2025-46333

z2d is a pure Zig 2D graphics library. Versions of z2d after `0.5.1` and up to and including `0.6.0`, when …
CVE-2025-6151

A vulnerability has been found in TP-Link TL-WR940N V4 and TL-WR841N V11. Affected by this issue is some unknown functionality …
CVE-2025-34096

A stack-based buffer overflow vulnerability exists in Easy File Sharing HTTP Server version 7.2. The flaw is triggered when a …

Don't wait for an exploit

Scan your website for vulnerabilities like CVE-2024-26883 — free, no signup required.