From: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
[ Upstream commit 095641817e1bf6aa2560e025e47575188ee3edaf ]
Dan Carpenter found via Smatch static checker, that unsigned 'mtu_lo' is
never less than zero.
Variable mtu_lo should have been an 'int', because read_mtu_device_lo()
uses minus as error indications.
Fixes: b62eba563229 ("selftests/bpf: Tests using bpf_check_mtu BPF-helper")
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
Link: https://lore.kernel.org/bpf/168605104733.3636467.17945947801753092590.stgit@firesoul
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/testing/selftests/bpf/prog_tests/check_mtu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/check_mtu.c b/tools/testing/selftests/bpf/prog_tests/check_mtu.c
index 5338d2ea04603..2a9a30650350e 100644
--- a/tools/testing/selftests/bpf/prog_tests/check_mtu.c
+++ b/tools/testing/selftests/bpf/prog_tests/check_mtu.c
@@ -183,7 +183,7 @@ static void test_check_mtu_tc(__u32 mtu, __u32 ifindex)
void serial_test_check_mtu(void)
{
- __u32 mtu_lo;
+ int mtu_lo;
if (test__start_subtest("bpf_check_mtu XDP-attach"))
test_check_mtu_xdp_attach();
--
2.39.2
