The optlen value passed by syzbot to _sys_setsockopt() is 2, which results in only 2 bytes being allocated when allocating memory to kernel_optval, and the optval size passed when calling the function copy_from_sockptr() is 4 bytes. Here, optlen is determined uniformly in the entry function __sys_setsockopt(). If its value is less than 4, the parameter is considered invalid. Reported-by: syzbot+837ba09d9db969068367@xxxxxxxxxxxxxxxxxxxxxxxxx Reported-by: syzbot+b71011ec0a23f4d15625@xxxxxxxxxxxxxxxxxxxxxxxxx Reported-by: syzbot+d4ecae01a53fd9b42e7d@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Edward Adam Davis <eadavis@xxxxxx> --- net/socket.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/socket.c b/net/socket.c index e5f3af49a8b6..ac8fd4f6ebfe 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 < sizeof(int)) + return -EINVAL; + sock = sockfd_lookup_light(fd, &err, &fput_needed); if (!sock) return err; -- 2.43.0
