Vulnerability in Linux

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: bpf: backtrack_insn(): Handle ld_{abs,ind} subprog exit edge Nicholas Carlini reported a bug in precision backtracking mechanism for BPF_LD | BPF_{IND,ABS} instructions. These instructions are modelled as two branches: - fallthrough; - implicit exit from current subprogram. The implicit exit case was not handled by the backtrack_insn() function. When backtracking such a path backtrack_insn() did not call bt_subprog_enter(), which meant that backtracking continued manipulating precision marks in a caller frame, while looking at instructions in a callee frame. This lead to segmentation faults during verification (see the selftest), or unsound state pruning.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund24 Sep 2026WID-SEC-2026-3579

  Linux Kernel: Multiple vulnerabilities Translated from German

  CVE-2026-97615CVE-2026-97978CVE-2026-98127+590 more CVEs

[ References ]References

• git.kernel.org/stable/c/12c064bcfa56e3631be9f5336ee113b7f849959a
• git.kernel.org/stable/c/19cca7c36055906b3cff3e297618ee8a50cde25d
• git.kernel.org/stable/c/387b1baefbb776e3f48dc2261e77a49213f470f7
• git.kernel.org/stable/c/671b7b9a660ef15b25faa3df161205b9dc8d1eb2
• git.kernel.org/stable/c/a0cd9e22f8faed30a8da8be357c51bd8b3074ee9