net: Fix references to out-of-scope variables in put_cmsg_compat()

In net/compat.c::put_cmsg_compat() we may assign 'data' the address of either the 'ctv' or 'cts' local variables inside the 'if (!COMPAT_USE_64BIT_TIME)' branch. Those variables go out of scope at the end of the 'if' statement, so when we use 'data' further down in 'copy_to_user(CMSG_COMPAT_DATA(cm), data, cmlen - sizeof(struct compat_cmsghdr))' there's no telling what it may be refering to - not good. Fix the problem by simply giving 'ctv' and 'cts' function scope. Signed-off-by: Jesper Juhl <[email protected]> Signed-off-by: David S. Miller <[email protected]>
jadonk · Jul 23, 2012 · 8188104 · 8188104
1 parent 5e9965c
commit 8188104
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/net/compat.c b/net/compat.c
@@ -221,6 +221,8 @@ int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *dat
 {
 	struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
 	struct compat_cmsghdr cmhdr;
+	struct compat_timeval ctv;
+	struct compat_timespec cts[3];
 	int cmlen;
 
 	if (cm == NULL || kmsg->msg_controllen < sizeof(*cm)) {
@@ -229,8 +231,6 @@ int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *dat
 	}
 
 	if (!COMPAT_USE_64BIT_TIME) {
-		struct compat_timeval ctv;
-		struct compat_timespec cts[3];
 		if (level == SOL_SOCKET && type == SCM_TIMESTAMP) {
 			struct timeval *tv = (struct timeval *)data;
 			ctv.tv_sec = tv->tv_sec;