diff options
| author | Alexei Starovoitov <ast@plumgrid.com> | 2014-10-20 21:54:57 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-10-22 01:43:46 (GMT) |
| commit | 32bf08a6257b9c7380dcd040af3c0858eee3ef05 (patch) | |
| tree | b5928993937cb9bc095f6c3e0393eb63f6471308 | |
| parent | 78fd1d0ab072d4d9b5f0b7c14a1516665170b565 (diff) | |
| download | linux-32bf08a6257b9c7380dcd040af3c0858eee3ef05.tar.xz | |
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: f1bca824dabb ("bpf: add search pruning optimization to verifier")
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | kernel/bpf/verifier.c | 3 | ||||
| -rw-r--r-- | samples/bpf/test_verifier.c | 11 |
2 files changed, 13 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 801f5f3..9f81818 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -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; } diff --git a/samples/bpf/test_verifier.c b/samples/bpf/test_verifier.c index f44ef11..eb4bec0 100644 --- a/samples/bpf/test_verifier.c +++ b/samples/bpf/test_verifier.c @@ -209,6 +209,17 @@ static struct bpf_test tests[] = { .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 = { BPF_ST_MEM(BPF_DW, BPF_REG_10, 8, 0), |