5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Willem de Bruijn willemb@google.com
[ Upstream commit 00a4f8fd9c750f20d8fd4535c71c9caa7ef5ff2f ]
Same init_rng() in both tests. The function reads /dev/urandom to initialize srand(). In case of failure, it falls back onto the entropy in the uninitialized variable. Not sure if this is on purpose. But failure reading urandom should be rare, so just fail hard. While at it, convert to getrandom(). Which man 4 random suggests is simpler and more robust.
mptcp_inq.c:525:6: mptcp_connect.c:1131:6:
error: variable 'foo' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
Fixes: 048d19d444be ("mptcp: add basic kselftest for mptcp") Fixes: b51880568f20 ("selftests: mptcp: add inq test case") Cc: Florian Westphal fw@strlen.de Signed-off-by: Willem de Bruijn willemb@google.com
----
When input is randomized because this is expected to meaningfully explore edge cases, should we also add 1. logging the random seed to stdout and 2. adding a command line argument to replay from a specific seed I can do this in net-next, if authors find it useful in this case. Reviewed-by: Matthieu Baerts matttbe@kernel.org
Link: https://lore.kernel.org/r/20231124171645.1011043-5-willemdebruijn.kernel@gma... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/net/mptcp/mptcp_connect.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.c b/tools/testing/selftests/net/mptcp/mptcp_connect.c index 77bb62feb8726..37c1ec888ba2e 100644 --- a/tools/testing/selftests/net/mptcp/mptcp_connect.c +++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c @@ -15,6 +15,7 @@ #include <unistd.h>
#include <sys/poll.h> +#include <sys/random.h> #include <sys/sendfile.h> #include <sys/stat.h> #include <sys/socket.h> @@ -734,15 +735,11 @@ int main_loop_s(int listensock)
static void init_rng(void) { - int fd = open("/dev/urandom", O_RDONLY); unsigned int foo;
- if (fd > 0) { - int ret = read(fd, &foo, sizeof(foo)); - - if (ret < 0) - srand(fd + foo); - close(fd); + if (getrandom(&foo, sizeof(foo), 0) == -1) { + perror("getrandom"); + exit(1); }
srand(foo);