| Message ID | 1413842097-4380-1-git-send-email-ast@plumgrid.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Mo, 2014-10-20 at 14:54 -0700, Alexei Starovoitov wrote: > 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> > --- > > while we were staring at the verifier code with Hannes during LPC > something felt odd in this spot. Yes. It was a bug. Fix it. > > kernel/bpf/verifier.c | 3 ++- > samples/bpf/test_verifier.c | 11 +++++++++++ > 2 files changed, 13 insertions(+), 1 deletion(-) > > 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; > } That makes sense. Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Thanks, Hannes -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Alexei Starovoitov <ast@plumgrid.com> Date: Mon, 20 Oct 2014 14:54:57 -0700 > 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> Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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),
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> --- while we were staring at the verifier code with Hannes during LPC something felt odd in this spot. Yes. It was a bug. Fix it. kernel/bpf/verifier.c | 3 ++- samples/bpf/test_verifier.c | 11 +++++++++++ 2 files changed, 13 insertions(+), 1 deletion(-)