Patch "strscpy: zero any trailing garbage bytes in the destination" has been added to the 3.18-stable tree

This is a note to let you know that I've just added the patch titled

strscpy: zero any trailing garbage bytes in the destination

to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
strscpy-zero-any-trailing-garbage-bytes-in-the-destination.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Chris Metcalf <[email protected]>
Date: Tue, 6 Oct 2015 12:37:41 -0400
Subject: strscpy: zero any trailing garbage bytes in the destination

From: Chris Metcalf <[email protected]>

commit 990486c8af044f89bddfbde1d1cf9fde449bedbf upstream.

It's possible that the destination can be shadowed in userspace (as, for example, the perf buffers are now). So we should take care not to leak data that could be inspected by userspace.

---
 lib/string.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -211,12 +211,13 @@ ssize_t strscpy(char *dest, const char *
 		unsigned long c, data;
 
 		c = *(unsigned long *)(src+res);
-		*(unsigned long *)(dest+res) = c;
 		if (has_zero(c, &data, &constants)) {
 			data = prep_zero_mask(c, data, &constants);
 			data = create_zero_mask(data);
+			*(unsigned long *)(dest+res) = c & zero_bytemask(data);
 			return res + find_zero(data);
 		}
+		*(unsigned long *)(dest+res) = c;
 		res += sizeof(unsigned long);
 		count -= sizeof(unsigned long);
 		max -= sizeof(unsigned long);

Patches currently in stable-queue which might be from [email protected] are

queue-3.18/strscpy-zero-any-trailing-garbage-bytes-in-the-destination.patch queue-3.18/string-provide-strscpy.patch