CVE-2024-26883bpf: Fix stackmap overflow check on 32-bit arches

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.

Timeline

Scores

EPSS (exploitation in 30 days)

0.25% · top 83% of all CVEs (14 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.

Affected products

• Linux · Linux

  • affected 063c722dd9d285d877e6fd499e753d6224f4c046 – < d0e214acc59145ce25113f617311aa79dda39cb3
  • affected 7e3a6b820535eb395784060ae26c5af579528fa0 – < 21e5fa4688e1a4d3db6b72216231b24232f75c1d
  • affected 8032bf2af9ce26b3a362b9711d15f626ab946a74 – < 15641007df0f0d35fa28742b25c2a7db9dcd6895
  • affected 6183f4d3a0a2ad230511987c6c362ca43ec0055f – < ca1f06e72dec41ae4f76e7b1a8a97265447b46ae
  • affected 6183f4d3a0a2ad230511987c6c362ca43ec0055f – < f06899582ccee09bd85d0696290e3eaca9aa042d
  • affected 6183f4d3a0a2ad230511987c6c362ca43ec0055f – < 7070b274c7866a4c5036f8d54fcaf315c64ac33a
  • affected 6183f4d3a0a2ad230511987c6c362ca43ec0055f – < 43f798b9036491fb014b55dd61c4c5c3193267d0
  • affected 6183f4d3a0a2ad230511987c6c362ca43ec0055f – < 0971126c8164abe2004b8536b49690a0d6005b0a
  • affected 6183f4d3a0a2ad230511987c6c362ca43ec0055f – < 7a4b21250bf79eef26543d35bd390448646c536b
  • affected 253150830a012adfccf90afcebae8fda5b05a80f
  • affected 766107351731ae223ebf60ca22bdfeb47ce6acc8
  • affected 4.19.177 – < 4.19.311
  • affected 5.4.99 – < 5.4.273
  • affected 5.10.17 – < 5.10.214
  • affected 4.9.258 – < 4.10
  • affected 4.14.222 – < 4.15

• Linux · Linux

  • affected 5.11
  • unaffected < 5.11
  • unaffected 4.19.311 – ≤ 4.19.*
  • unaffected 5.4.273 – ≤ 5.4.*
  • unaffected 5.10.214 – ≤ 5.10.*
  • unaffected 5.15.153 – ≤ 5.15.*
  • unaffected 6.1.83 – ≤ 6.1.*
  • unaffected 6.6.23 – ≤ 6.6.*
  • unaffected 6.7.11 – ≤ 6.7.*
  • unaffected 6.8.2 – ≤ 6.8.*
  • unaffected 6.9 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2024-24145 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2024-26883](https://cveledger.app/badge/CVE-2024-26883.svg)](https://cveledger.app/cve/CVE-2024-26883)

Record last updated 15 Oct 2026, 00:39 UTC.