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CVE-2024-26884

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix hashtab overflow check on 32-bit arches The hashtab code relies on roundup_pow_of_two() to…

Published Apr 17, 2024 · updated Oct 15, 2026 · linux linux kernel

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix hashtab overflow check on 32-bit arches The hashtab 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. So apply the same fix to hashtab, by moving the overflow check to before the roundup.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 17, 2024 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: bpf: Fix hashtab overflow check on 32-bit arches The hashtab 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, whic

  2. Oct 15, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: bpf: Fix hashtab overflow check on 32-bit arches The hashtab 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, whic

Affected

  • cpe linux/linux kernelversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2024-26884

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2024-26884

    30-day exploitation probability 0.3%

    first.org
  • NIST NVDVulnerability recordCVE-2024-26884

    In the Linux kernel, the following vulnerability has been resolved: bpf: Fix hashtab overflow check on 32-bit arches The hashtab 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. Ho

    nvd.nist.gov

References