From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47666) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WVkrm-0006YD-Ke for qemu-devel@nongnu.org; Thu, 03 Apr 2014 12:51:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WVkrg-0005nJ-Bg for qemu-devel@nongnu.org; Thu, 03 Apr 2014 12:51:50 -0400 Date: Thu, 3 Apr 2014 19:52:13 +0300 From: "Michael S. Tsirkin" Message-ID: <1396543778-22307-21-git-send-email-mst@redhat.com> References: <1396543778-22307-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1396543778-22307-1-git-send-email-mst@redhat.com> Subject: [Qemu-devel] [PATCH v5 20/24] zaurus: fix buffer overrun on invalid state load List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , mdroth@linux.vnet.ibm.com, Stefan Weil , qemu-stable@nongnu.org, dgilbert@redhat.com, Paolo Bonzini , =?us-ascii?B?PT9VVEYtOD9xP0FuZHJlYXM9MjBGPUMzPUE0cmJlcj89?= CVE-2013-4540 Within scoop_gpio_handler_update, if prev_level has a high bit set, then we get bit > 16 and that causes a buffer overrun. Since prev_level comes from wire indirectly, this can happen on invalid state load. Similarly for gpio_level and gpio_dir. To fix, limit to 16 bit. Reported-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Dr. David Alan Gilbert --- hw/gpio/zaurus.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/hw/gpio/zaurus.c b/hw/gpio/zaurus.c index dc79a8b..8e2ce04 100644 --- a/hw/gpio/zaurus.c +++ b/hw/gpio/zaurus.c @@ -203,6 +203,15 @@ static bool is_version_0 (void *opaque, int version_id) return version_id == 0; } +static bool vmstate_scoop_validate(void *opaque, int version_id) +{ + ScoopInfo *s = opaque; + + return !(s->prev_level & 0xffff0000) && + !(s->gpio_level & 0xffff0000) && + !(s->gpio_dir & 0xffff0000); +} + static const VMStateDescription vmstate_scoop_regs = { .name = "scoop", .version_id = 1, @@ -215,6 +224,7 @@ static const VMStateDescription vmstate_scoop_regs = { VMSTATE_UINT32(gpio_level, ScoopInfo), VMSTATE_UINT32(gpio_dir, ScoopInfo), VMSTATE_UINT32(prev_level, ScoopInfo), + VMSTATE_VALIDATE("irq levels are 16 bit", vmstate_scoop_validate), VMSTATE_UINT16(mcr, ScoopInfo), VMSTATE_UINT16(cdr, ScoopInfo), VMSTATE_UINT16(ccr, ScoopInfo), -- MST