[PATCH net-next 2/8] bpf: don't check spilled reg state for non-STACK_SPILLed type slots
flat view
STALE3414d
REVIEWED: 5 (5M)
From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2017-06-10 22:50:58
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Revision v1 of 3 in this series; 1 review trailer (1 from subsystem maintainers).
spilled_regs[] state is only used for stack slots of type STACK_SPILL, never for STACK_MISC. Right now, in states_equal(), even if we have old and current stack state of type STACK_MISC, we compare spilled_regs[] for that particular offset. Just skip these like we do everywhere else. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> --- kernel/bpf/verifier.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 14ccb07..d031b3b 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c@@ -2828,6 +2828,8 @@ static bool states_equal(struct bpf_verifier_env *env, return false; if (i % BPF_REG_SIZE) continue; + if (old->stack_slot_type[i] != STACK_SPILL) + continue; if (memcmp(&old->spilled_regs[i / BPF_REG_SIZE], &cur->spilled_regs[i / BPF_REG_SIZE], sizeof(old->spilled_regs[0])))
--
1.9.3