[PATCH 5.4 093/191] selftests/seccomp: Zero out seccomp_notif

[Greg Kroah-Hartman]

From: Sargun Dhillon <sargun@xxxxxxxxx>

commit 88c13f8bd71472fbab5338b01d99122908c77e53 upstream.

The seccomp_notif structure should be zeroed out prior to calling the
SECCOMP_IOCTL_NOTIF_RECV ioctl. Previously, the kernel did not check
whether these structures were zeroed out or not, so these worked.

This patch zeroes out the seccomp_notif data structure prior to calling
the ioctl.

Signed-off-by: Sargun Dhillon <sargun@xxxxxxxxx>
Reviewed-by: Tycho Andersen <tycho@xxxxxxxx>
Reviewed-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20191229062451.9467-1-sargun@xxxxxxxxx
Fixes: 6a21cc50f0c7 ("seccomp: add a return code to trap to userspace")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 tools/testing/selftests/seccomp/seccomp_bpf.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -3267,6 +3267,7 @@ TEST(user_notification_signal)
 
 	close(sk_pair[1]);
 
+	memset(&req, 0, sizeof(req));
 	EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
 
 	EXPECT_EQ(kill(pid, SIGUSR1), 0);
@@ -3285,6 +3286,7 @@ TEST(user_notification_signal)
 	EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
 	EXPECT_EQ(errno, ENOENT);
 
+	memset(&req, 0, sizeof(req));
 	EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
 
 	resp.id = req.id;