ZeroDay Findings
Sign inSign up

Findings

CVE-2025-40078

In the Linux kernel, the following vulnerability has been resolved: bpf: Explicitly check accesses to bpf_sock_addr Syzkaller found a kernel warning on the following s…

Published Oct 28, 2025 · updated Oct 15, 2026

In the Linux kernel, the following vulnerability has been resolved: bpf: Explicitly check accesses to bpf_sock_addr Syzkaller found a kernel warning on the following sock_addr program: 0: r0 = 0 1: r2 = *(u32 *)(r1 +60) 2: exit which triggers: verifier bug: error during ctx access conversion (0) This is happening because offset 60 in bpf_sock_addr corresponds to an implicit padding of 4 bytes, right after msg_src_ip4. Access to this padding isn't rejected in sock_addr_is_valid_access and it thus later fails to convert the access. This patch fixes it by explicitly checking the various fields of bpf_sock_addr in sock_addr_is_valid_access. I checked the other ctx structures and is_valid_access functions and didn't find any other similar cases. Other cases of (properly handled) padding are covered in new tests in a subsequent patch.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 28, 2025 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: bpf: Explicitly check accesses to bpf_sock_addr Syzkaller found a kernel warning on the following sock_addr program: 0: r0 = 0 1: r2 = *(u32 *)(r1 +60) 2: exit which triggers: verifier bug: error during ctx access conversion (0) This is happening because offset 60 in bpf_sock_addr corresponds to an implicit padding of 4 bytes, rig

  2. Oct 15, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: bpf: Explicitly check accesses to bpf_sock_addr Syzkaller found a kernel warning on the following sock_addr program: 0: r0 = 0 1: r2 = *(u32 *)(r1 +60) 2: exit which triggers: verifier bug: error during ctx access conversion (0) This is happening because offset 60 in bpf_sock_addr corresponds to an implicit padding of 4 bytes, rig

Sources

  • CVE.orgVulnerability recordCVE-2025-40078

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-40078

    30-day exploitation probability 0.2%

    first.org
  • NIST NVDVulnerability recordCVE-2025-40078

    In the Linux kernel, the following vulnerability has been resolved: bpf: Explicitly check accesses to bpf_sock_addr Syzkaller found a kernel warning on the following sock_addr program: 0: r0 = 0 1: r2 = *(u32 *)(r1 +60) 2: exit which triggers: verifier bug: e

    nvd.nist.gov

References