Additional logging in is_state_visited(): if infinite loop is detected print full verifier state for both current and equivalent states. Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx> Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx> --- kernel/bpf/verifier.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index f23fbfe82c59..98f9d0f35931 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -16928,6 +16928,10 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx) !iter_active_depths_differ(&sl->state, cur)) { verbose_linfo(env, insn_idx, "; "); verbose(env, "infinite loop detected at insn %d\n", insn_idx); + verbose(env, "cur state:"); + print_verifier_state(env, cur->frame[cur->curframe], true); + verbose(env, "old state:"); + print_verifier_state(env, sl->state.frame[cur->curframe], true); return -EINVAL; } /* if the verifier is processing a loop, avoid adding new state -- 2.42.0