Commit e0bf4622 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
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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: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-3-andrii@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 5956f301

kernel/bpf/verifier.c

+3 −0
Original line number Diff line number Diff line
@@ -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 = &reg_state->stack[spi].spilled_ptr;









	mark_stack_slot_scratched(env, spi);

















	if (is_spilled_reg(&reg_state->stack[spi])) {









		u8 spill_size = 1;