Patch "x86-64: Fix the failure case in copy_user_handle_tail()" has been added to the 3.0-stable tree

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

    x86-64: Fix the failure case in copy_user_handle_tail()

to the 3.0-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:
     x86-64-fix-the-failure-case-in-copy_user_handle_tail.patch
and it can be found in the queue-3.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From 66db3feb486c01349f767b98ebb10b0c3d2d021b Mon Sep 17 00:00:00 2001
From: CQ Tang <cq.tang@xxxxxxxxx>
Date: Mon, 18 Mar 2013 11:02:21 -0400
Subject: x86-64: Fix the failure case in copy_user_handle_tail()

From: CQ Tang <cq.tang@xxxxxxxxx>

commit 66db3feb486c01349f767b98ebb10b0c3d2d021b upstream.

The increment of "to" in copy_user_handle_tail() will have incremented
before a failure has been noted.  This causes us to skip a byte in the
failure case.

Only do the increment when assured there is no failure.

Signed-off-by: CQ Tang <cq.tang@xxxxxxxxx>
Link: http://lkml.kernel.org/r/20130318150221.8439.993.stgit@xxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/x86/lib/usercopy_64.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -169,10 +169,10 @@ copy_user_handle_tail(char *to, char *fr
 	char c;
 	unsigned zero_len;
 
-	for (; len; --len) {
+	for (; len; --len, to++) {
 		if (__get_user_nocheck(c, from++, sizeof(char)))
 			break;
-		if (__put_user_nocheck(c, to++, sizeof(char)))
+		if (__put_user_nocheck(c, to, sizeof(char)))
 			break;
 	}
 


Patches currently in stable-queue which might be from cq.tang@xxxxxxxxx are

queue-3.0/x86-64-fix-the-failure-case-in-copy_user_handle_tail.patch
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