Re: [PATCH bpf-next v4 10/18] bpf: Fix interaction between stack argument PTR_TO_STACK and dead slot poisoning

bot+bpf-ci
2026-04-12T05:43:15Z

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commit 7570556100592966981ed4784bb775307405e5f0
Author: Yonghong Song <yonghong.song@linux.dev>

bpf: Fix interaction between stack argument PTR_TO_STACK and dead slot poisoning

This commit fixes a false rejection where the verifier rejects valid
cross-frame stack reads because the static liveness pass cannot track
indirect references through stack-argument-passed pointers, causing
parent frame slots to be incorrectly poisoned.

This patch fixes a bug introduced by an earlier commit in the same
series but does not include a Fixes: tag. The issue is introduced
when stack argument support is added, because BPF_REG_STACK_ARG_BASE
(r12) is not tracked by the liveness pass. Without attribution, it
is harder to identify the scope of the fix during bisection or
stable backporting.

Would it make sense to add:

Fixes: 442d7da1edaf ("bpf: Support stack arguments for bpf functions")

---
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CI run summary: https://github.com/kernel-patches/bpf/actions/runs/24299298635