Commit 32bf08a6 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by David S. Miller

bpf: fix bug in eBPF verifier

while comparing for verifier state equivalency the comparison
was missing a check for uninitialized register.
Make sure it does so and add a testcase.

Fixes: f1bca824 ("bpf: add search pruning optimization to verifier")
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 78fd1d0a
......@@ -1409,7 +1409,8 @@ static bool states_equal(struct verifier_state *old, struct verifier_state *cur)
if (memcmp(&old->regs[i], &cur->regs[i],
sizeof(old->regs[0])) != 0) {
if (old->regs[i].type == NOT_INIT ||
old->regs[i].type == UNKNOWN_VALUE)
(old->regs[i].type == UNKNOWN_VALUE &&
cur->regs[i].type != NOT_INIT))
continue;
return false;
}
......
......@@ -208,6 +208,17 @@ static struct bpf_test tests[] = {
.errstr = "R0 !read_ok",
.result = REJECT,
},
{
"program doesn't init R0 before exit in all branches",
.insns = {
BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 2),
BPF_EXIT_INSN(),
},
.errstr = "R0 !read_ok",
.result = REJECT,
},
{
"stack out of bounds",
.insns = {
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment