6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ning Ding [ Upstream commit 83608e303b95d07afba1c15da0b5d9e513c2f15a ] An iterator stack slot can be MEM_RCU or PTR_UNTRUSTED. These states must not be equal, or the verifier can prune an unsafe path. Compare the pointer type for STACK_ITER slots. Fixes: dfab99df147b ("bpf: teach the verifier to enforce css_iter and task_iter in RCU CS") Signed-off-by: Ning Ding Acked-by: Eduard Zingerman Link: https://patch.msgid.link/20260811035955.132989-2-dingning04@gmail.com Signed-off-by: Eduard Zingerman Signed-off-by: Sasha Levin --- kernel/bpf/verifier.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 8cd9526c0dac9..947b501a58aee 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -19488,7 +19488,8 @@ static bool stacksafe(struct bpf_verifier_env *env, struct bpf_func_state *old, * infinite loop check triggering, see * iter_active_depths_differ() */ - if (old_reg->iter.btf != cur_reg->iter.btf || + if (old_reg->type != cur_reg->type || + old_reg->iter.btf != cur_reg->iter.btf || old_reg->iter.btf_id != cur_reg->iter.btf_id || old_reg->iter.state != cur_reg->iter.state || /* ignore {old_reg,cur_reg}->iter.depth, see above */ -- 2.53.0