Commit 49aa4058 authored Sep 30, 2013 by Stefan Weil Committed by Michael Tokarev Oct 05, 2013

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 6ea314d9 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>

parent 4b351a0f

qemu-char.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -2989,11 +2989,11 @@ QemuOpts qemu_chr_parse_compat(const char label, const char *filename)
		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);