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).
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
The product reads data past the end, or before the beginning, of the intended buffer.
| Link | Tags |
|---|---|
| https://ubuntu.com/security/notices/USN-4950-1 | third party advisory vendor advisory |
| https://ubuntu.com/security/notices/USN-4949-1 | third party advisory vendor advisory |
| https://www.openwall.com/lists/oss-security/2021/05/11/11 | mailing list third party advisory patch |
| https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=049c4e13714ecbca567b4d5f6d563f05d431c80e | patch vendor advisory |
| https://www.zerodayinitiative.com/advisories/ZDI-21-606/ | vdb entry third party advisory |
| https://security.netapp.com/advisory/ntap-20210716-0004/ | third party advisory |
| http://packetstormsecurity.com/files/164015/Linux-eBPF-ALU32-32-bit-Invalid-Bounds-Tracking-Local-Privilege-Escalation.html | exploit vdb entry third party advisory |