[PATCH 7.1 002/271] selftests/bpf: Fail unbound UDP on sockmap update

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

7.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Michal Luczaj <mhal@rbox.co>

[ Upstream commit 203b06932777b9ad5085319389dea566f5c2ca63 ]

sockmap now rejects unbound UDP sockets. Adjust test_maps. While at it,
check socket()'s return value.

This effectively reverts commit c39aa2159974 ("bpf, selftests: Fix
test_maps now that sockmap supports UDP").

Signed-off-by: Michal Luczaj <mhal@rbox.co>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20260707-sockmap-lookup-udp-leak-v4-4-f878346f27ab@rbox.co
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Ricardo B. Marlière (SUSE) <ricardo@marliere.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/test_maps.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index ccc5acd55ff9d..d194b44ff8be8 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -748,16 +748,15 @@ static void test_sockmap(unsigned int tasks, void *data)
 		goto out_sockmap;
 	}
 
-	/* Test update with unsupported UDP socket */
+	/* Test update with unsupported unbound UDP socket */
 	udp = socket(AF_INET, SOCK_DGRAM, 0);
-	i = 0;
-	err = bpf_map_update_elem(fd, &i, &udp, BPF_ANY);
-	if (err) {
-		printf("Failed socket update SOCK_DGRAM '%i:%i'\n",
-		       i, udp);
+	CHECK(udp < 0, "socket(AF_INET, SOCK_DGRAM)", "errno:%d\n", errno);
+	err = bpf_map_update_elem(fd, &(int){0}, &udp, BPF_ANY);
+	close(udp);
+	if (!err) {
+		printf("Unexpectedly succeeded unbound UDP update '0:%i'\n", udp);
 		goto out_sockmap;
 	}
-	close(udp);
 
 	/* Test update without programs */
 	for (i = 0; i < 6; i++) {
-- 
2.53.0