[PATCH 4.15 067/128] bpf: fix stack state printing in verifier log

[Greg Kroah-Hartman]

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alexei Starovoitov <ast@xxxxxx>


[ Upstream commit 12a3cc8424fe1237aaeb982dec4f0914ddd22f3e ]

fix incorrect stack state prints in print_verifier_state()

Fixes: 638f5b90d460 ("bpf: reduce verifier memory consumption")
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>
Acked-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 kernel/bpf/verifier.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -279,7 +279,7 @@ static void print_verifier_state(struct
 	for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
 		if (state->stack[i].slot_type[0] == STACK_SPILL)
 			verbose(env, " fp%d=%s",
-				-MAX_BPF_STACK + i * BPF_REG_SIZE,
+				(-i - 1) * BPF_REG_SIZE,
 				reg_type_str[state->stack[i].spilled_ptr.type]);
 	}
 	verbose(env, "\n");