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 <jj@chaosbits.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jesper Juhl 2012-07-22 11:37:20 +00:00 committed by David S. Miller
parent 5e9965c15b
commit 818810472b

View File

@ -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;