Commit 81881047 authored Jul 22, 2012 by Jesper Juhl Committed by David S. Miller Jul 22, 2012

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>

parent 5e9965c1

net/compat.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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;

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