net: compat_sys_recvmmsg user timespec arg can be NULL

We must test if user timespec is non-NULL before copying from userpace, same as sys_recvmmsg(). Commiter note: changed it so that we have just one branch. Signed-off-by: Jean-Mickael Guerin <[email protected]> Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: David S. Miller <[email protected]>
redpig · Dec 2, 2009 · 5b23136 · 5b23136
1 parent d7256d0
commit 5b23136
Showing 1 changed file with 6 additions and 2 deletions.
diff --git a/net/compat.c b/net/compat.c
@@ -758,9 +758,13 @@ asmlinkage long compat_sys_recvmmsg(int fd, struct compat_mmsghdr __user *mmsg,
 {
 	int datagrams;
 	struct timespec ktspec;
-	struct compat_timespec __user *utspec =
-			(struct compat_timespec __user *)timeout;
+	struct compat_timespec __user *utspec;
 
+	if (timeout == NULL)
+		return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
+				      flags | MSG_CMSG_COMPAT, NULL);
+
+	utspec = (struct compat_timespec __user *)timeout;
 	if (get_user(ktspec.tv_sec, &utspec->tv_sec) ||
 	    get_user(ktspec.tv_nsec, &utspec->tv_nsec))
 		return -EFAULT;