b23eae9fc7
[ Upstream commit eceae70bdeaeb6b8ceb662983cf663ff352fbc96 ] strncat()'s third argument is how many bytes will be added *in addition* to already existing bytes in destination. Plus extra zero byte will be added after that. So existing use in test_sockmap has many opportunities to overflow the string and cause memory corruptions. And in this case, GCC complains for a good reason. Fixes:16962b2404("bpf: sockmap, add selftests") Fixes:73563aa3d9("selftests/bpf: test_sockmap, print additional test options") Fixes:1ade9abadf("bpf: test_sockmap, add options for msg_pop_data() helper") Fixes:463bac5f1c("bpf, selftests: Add test for ktls with skb bpf ingress policy") Fixes:e9dd904708("bpf: add tls support for testing in test_sockmap") Fixes:753fb2ee09("bpf: sockmap, add msg_peek tests to test_sockmap") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201203235440.2302137-2-andrii@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>