title: Linux kernel eBPF bitwise ops ALU32 bounds tracking
description: The eBPF ALU32 bounds tracking for bitwise ops (AND, OR and XOR) in the Linux kernel did not properly update 32-bit bounds, which could be turned into out of bounds reads and writes in the Linux kernel and therefore, arbitrary code execution. This issue was fixed via commit 049c4e13714e ("bpf: Fix alu32 const subreg bound tracking on bitwise operations") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. The AND/OR issues were introduced by commit 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") (5.7-rc1) and the XOR variant was introduced by 2921c90d4718 ("bpf:Fix a verifier failure with xor") ( 5.10-rc1).
problem types: CWE-787 Out-of-bounds Write
affected:
{
product: Linux kernel
vendor: Linux
versions:
lessThan: v5.13-rc4, status: affected, version: trunk, versionType: custom
lessThan: v5.12.4, status: affected, version: linux-5.12.y, versionType: custom
lessThan: v5.11.21, status: affected, version: linux-5.11.y, versionType: custom
lessThan: v5.10.37, status: affected, version: linux-5.10.y, versionType: custom
lessThan: 5.7*, status: affected, version: v5.7-rc1, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: HIGH
attackVector: LOCAL
availabilityImpact: HIGH
baseScore: 7.8
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: LOW
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
version: 3.1
]