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.
History

Fri, 22 Nov 2024 12:00:00 +0000


Wed, 06 Nov 2024 20:15:00 +0000

Type Values Removed Values Added
References
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 12 Sep 2024 20:30:00 +0000

Type Values Removed Values Added
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{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 11 Sep 2024 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-04-17T10:27:39.036Z

Updated: 2024-12-19T08:49:26.752Z

Reserved: 2024-02-19T14:20:24.185Z

Link: CVE-2024-26883

cve-icon Vulnrichment

Updated: 2024-08-02T00:21:05.381Z

cve-icon NVD

Status : Modified

Published: 2024-04-17T11:15:10.113

Modified: 2024-11-21T09:03:17.527

Link: CVE-2024-26883

cve-icon Redhat

Severity : Low

Publid Date: 2024-04-17T00:00:00Z

Links: CVE-2024-26883 - Bugzilla