diff mbox series

[4.19,4/4] bpf, selftests: Adjust few selftest outcomes wrt unreachable code

Message ID 20210812170037.2370387-5-ovidiu.panait@windriver.com
State New
Headers show
Series bpf: backport fixes for CVE-2021-33624 | expand

Commit Message

Ovidiu Panait Aug. 12, 2021, 5 p.m. UTC 
From: Daniel Borkmann <daniel@iogearbox.net>

commit 973377ffe8148180b2651825b92ae91988141b05 upstream.

In almost all cases from test_verifier that have been changed in here, we've
had an unreachable path with a load from a register which has an invalid
address on purpose. This was basically to make sure that we never walk this
path and to have the verifier complain if it would otherwise. Change it to
match on the right error for unprivileged given we now test these paths
under speculative execution.

There's one case where we match on exact # of insns_processed. Due to the
extra path, this will of course mismatch on unprivileged. Thus, restrict the
test->insn_processed check to privileged-only.

In one other case, we result in a 'pointer comparison prohibited' error. This
is similarly due to verifying an 'invalid' branch where we end up with a value
pointer on one side of the comparison.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
[OP: ignore changes to tests that do not exist in 4.19]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
---
 tools/testing/selftests/bpf/test_verifier.c | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index b44324530948..c7d17781dbfe 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -2792,6 +2792,8 @@  static struct bpf_test tests[] = {
 			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_7, 0),
 			BPF_EXIT_INSN(),
 		},
+		.errstr_unpriv = "R7 invalid mem access 'inv'",
+		.result_unpriv = REJECT,
 		.result = ACCEPT,
 		.retval = 0,
 	},