commit 49aa4058ac6dd0081aaa45776f07c98df397ca5e
author Stefan Weil <sw@weilnetz.de> Mon Sep 30 23:04:49 2013 +0200
committer Michael Tokarev <mjt@tls.msk.ru> Sat Oct 05 13:05:15 2013 +0400
tree 810fdef3de54da503f6bd3207fc7728bb1724f8c
parent 4b351a0f212769deda960da44e299f44d5da0737

qemu-char: Fix potential out of bounds access to local arrays

Latest gcc-4.8 supports a new option -fsanitize=address which activates
an AddressSanitizer. This AddressSanitizer stops the QEMU system emulation
very early because two character arrays of size 8 are potentially written
with 9 bytes.

Commit 6ea314d91439741e95772dfbab98b4135e04bebb added the code.

There is no obvious reason why width or height could need 8 characters,
so reduce it to 7 characters which together with the terminating '\0'
fit into the arrays.

Cc: qemu-stable <qemu-stable@nongnu.org>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Alex Bennée <alex@bennee.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

qemu-char.c

diff --git a/qemu-char.c b/qemu-char.c
index f7f5464..6d393e6 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -2989,11 +2989,11 @@
     if (strstart(filename, "vc", &p)) {
         qemu_opt_set(opts, "backend", "vc");
         if (*p == ':') {
-            if (sscanf(p+1, "%8[0-9]x%8[0-9]", width, height) == 2) {
+            if (sscanf(p+1, "%7[0-9]x%7[0-9]", width, height) == 2) {
                 /* pixels */
                 qemu_opt_set(opts, "width", width);
                 qemu_opt_set(opts, "height", height);
-            } else if (sscanf(p+1, "%8[0-9]Cx%8[0-9]C", width, height) == 2) {
+            } else if (sscanf(p+1, "%7[0-9]Cx%7[0-9]C", width, height) == 2) {
                 /* chars */
                 qemu_opt_set(opts, "cols", width);
                 qemu_opt_set(opts, "rows", height);