CVE-2025-40078

Description

In the Linux kernel, the following vulnerability has been resolved:bpf: Explicitly check accesses to bpf_sock_addrSyzkaller found a kernel warning on the following sock_addr program: 0: r0 = 0 1: r2 = *(u32 *)(r1 +60) 2: exitwhich triggers: verifier bug: error during ctx access conversion (0)This is happening because offset 60 in bpf_sock_addr corresponds to animplicit padding of 4 bytes, right after msg_src_ip4. Access to thispadding isnt rejected in sock_addr_is_valid_access and it thus laterfails to convert the access.This patch fixes it by explicitly checking the various fields ofbpf_sock_addr in sock_addr_is_valid_access.I checked the other ctx structures and is_valid_access functions anddidnt find any other similar cases. Other cases of (properly handled)padding are covered in new tests in a subsequent patch.

Risk Information

Base Score

5.5

MODERATE

Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U

EPSS Score

Exploitation Probability

0.068

Associated Vulnerability

No records found

Patch Details

No records found

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234