CVE-2024-40996

In the Linux kernel, the following vulnerability has been resolved:

bpf: Avoid splat in pskb_pull_reason

syzkaller builds (CONFIG_DEBUG_NET=y) frequently trigger a debug hint in pskb_may_pull.

Wed like to retain this debug check because it might hint at integer overflows and other issues (kernel code should pull headers, not huge value).

In bpf case, this splat isnt interesting at all: such (nonsensical) bpf programs are typically generated by a fuzzer anyway.

Do what Eric suggested and suppress such warning.

For CONFIG_DEBUG_NET=n we dont need the extra check because pskb_may_pull will do the right thing: return an error without the WARN() backtrace.

Affected Software

References

• https://git.kernel.org/stable/c/2bbe3e5a2f4ef69d13be54f1cf895b4658287080
• https://git.kernel.org/stable/c/5e90258303a358e88737afb5048bee9113beea3a
• https://git.kernel.org/stable/c/7f9644782c559635bd676c12c59389a34ed7c866
• https://git.kernel.org/stable/c/dacc15e9cb248d19e5fc63c54bef0b9b55007761