From 353c481229cb2f250e7acabe1ca1c91115fb9e4b Mon Sep 17 00:00:00 2001 From: Shardul Bankar Date: Tue, 21 Oct 2025 13:38:46 +0530 Subject: [PATCH] bpf: liveness: clarify get_outer_instance() handling in propagate_to_outer_instance() propagate_to_outer_instance() calls get_outer_instance() and uses the returned pointer to reset and commit stack write marks. Under normal conditions, update_instance() guarantees that an outer instance exists, so get_outer_instance() cannot return an ERR_PTR. However, explicitly checking for IS_ERR(outer_instance) makes this code more robust and self-documenting. It reduces cognitive load when reading the control flow and silences potential false-positive reports from static analysis or automated tooling. No functional change intended. Reported-by: kernel-patches-review-bot (https://github.com/kernel-patches/bpf/pull/10006#issuecomment-3409419240) Suggested-by: Eduard Zingerman Signed-off-by: Shardul Bankar Acked-by: Eduard Zingerman --- kernel/bpf/liveness.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/bpf/liveness.c b/kernel/bpf/liveness.c index 1e6538f59a786..baa742e6cbb65 100644 --- a/kernel/bpf/liveness.c +++ b/kernel/bpf/liveness.c @@ -524,6 +524,8 @@ static int propagate_to_outer_instance(struct bpf_verifier_env *env, this_subprog_start = callchain_subprog_start(callchain); outer_instance = get_outer_instance(env, instance); + if (IS_ERR(outer_instance)) + return PTR_ERR(outer_instance); callsite = callchain->callsites[callchain->curframe - 1]; reset_stack_write_marks(env, outer_instance, callsite);