sizeof(new_cc) is not real memory size that new_cc point to, introduce new_cc_len to store size then pass it to bpf_setsockopt().

Fixes: 31123c0360e0 ("selftests/bpf: bpf_setsockopt tests") Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- tools/testing/selftests/bpf/progs/setget_sockopt.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/setget_sockopt.c b/tools/testing/selftests/bpf/progs/setget_sockopt.c index 4a4cb44a4a15..40606ef47a38 100644 --- a/tools/testing/selftests/bpf/progs/setget_sockopt.c +++ b/tools/testing/selftests/bpf/progs/setget_sockopt.c @@ -305,15 +305,19 @@ static int bpf_test_tcp_sockopt(__u32 i, struct loop_ctx *lc) if (t->opt == TCP_CONGESTION) { char old_cc[16], tmp_cc[16]; const char *new_cc; + int new_cc_len;

if (bpf_getsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION, old_cc, sizeof(old_cc))) return 1; - if (!bpf_strncmp(old_cc, sizeof(old_cc), cubic_cc)) + if (!bpf_strncmp(old_cc, sizeof(old_cc), cubic_cc)) { new_cc = reno_cc; - else + new_cc_len = sizeof(reno_cc); + } else { new_cc = cubic_cc; + new_cc_len = sizeof(cubic_cc); + } if (bpf_setsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION, (void *)new_cc, - sizeof(new_cc))) + new_cc_len)) return 1; if (bpf_getsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION, tmp_cc, sizeof(tmp_cc))) return 1;