Patch "lib/hexdump.c: truncate output in case of overflow" has been added to the 4.3-stable tree

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

lib/hexdump.c: truncate output in case of overflow

to the 4.3-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:
lib-hexdump.c-truncate-output-in-case-of-overflow.patch
and it can be found in the queue-4.3 subdirectory.

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

From: Andy Shevchenko <[email protected]>
Date: Fri, 6 Nov 2015 16:31:31 -0800
Subject: lib/hexdump.c: truncate output in case of overflow

From: Andy Shevchenko <[email protected]>

commit 9f029f540c2f7e010e4922d44ba0dfd05da79f88 upstream.

There is a classical off-by-one error in case when we try to place, for example, 1+1 bytes as hex in the buffer of size 6. The expected result is to get an output truncated, but in the reality we get 6 bytes filed followed by terminating NUL.

Change the logic how we fill the output in case of byte dumping into limited space. This will follow the snprintf() behaviour by truncating output even on half bytes.

---
 lib/hexdump.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

@@ -169,11 +169,15 @@ int hex_dump_to_buffer(const void *buf,
 		}
 	} else {
 		for (j = 0; j < len; j++) {
-			if (linebuflen < lx + 3)
+			if (linebuflen < lx + 2)
 				goto overflow2;
 			ch = ptr[j];
 			linebuf[lx++] = hex_asc_hi(ch);
+			if (linebuflen < lx + 2)
+				goto overflow2;
 			linebuf[lx++] = hex_asc_lo(ch);
+			if (linebuflen < lx + 2)
+				goto overflow2;
 			linebuf[lx++] = ' ';
 		}
 		if (j)

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

queue-4.3/lib-hexdump.c-truncate-output-in-case-of-overflow.patch