From e0bf462276b6ee23203365eacb5c599f42a5a084 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 4 May 2023 21:33:09 -0700 Subject: bpf: mark relevant stack slots scratched for register read instructions When handling instructions that read register slots, mark relevant stack slots as scratched so that verifier log would contain those slots' states, in addition to currently emitted registers with stack slot offsets. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20230505043317.3629845-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- kernel/bpf/verifier.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel/bpf/verifier.c') diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index ff4a8ab99f08..da8a5834f2ca 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4109,6 +4109,7 @@ static void mark_reg_stack_read(struct bpf_verifier_env *env, for (i = min_off; i < max_off; i++) { slot = -i - 1; spi = slot / BPF_REG_SIZE; + mark_stack_slot_scratched(env, spi); stype = ptr_state->stack[spi].slot_type; if (stype[slot % BPF_REG_SIZE] != STACK_ZERO) break; @@ -4160,6 +4161,8 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env, stype = reg_state->stack[spi].slot_type; reg = ®_state->stack[spi].spilled_ptr; + mark_stack_slot_scratched(env, spi); + if (is_spilled_reg(®_state->stack[spi])) { u8 spill_size = 1; -- cgit v1.2.3