Re: [syzbot] [bluetooth?] KASAN: slab-out-of-bounds Read in l2cap_sock_setsockopt

[Edward Adam Davis <eadavis@qq.com>]

please test oob in rfcomm_sock_setsockopt

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git fe46a7dd189e

diff --git a/net/socket.c b/net/socket.c
index e5f3af49a8b6..d5b2ab6c859c 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2327,6 +2327,9 @@ int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
 	int err, fput_needed;
 	struct socket *sock;
 
+	if (optlen < 4)
+		return -EINVAL;
+
 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
 	if (!sock)
 		return err;