From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41894) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VnsnA-00069M-4O for qemu-devel@nongnu.org; Tue, 03 Dec 2013 11:25:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Vnsn2-0006oy-PQ for qemu-devel@nongnu.org; Tue, 03 Dec 2013 11:25:43 -0500 Date: Tue, 3 Dec 2013 18:29:01 +0200 From: "Michael S. Tsirkin" Message-ID: <1386087086-3691-16-git-send-email-mst@redhat.com> References: <1386087086-3691-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1386087086-3691-1-git-send-email-mst@redhat.com> Subject: [Qemu-devel] [PATCH 15/23] pxa2xx: avoid buffer overrun on incoming migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , qemu-stable@nongnu.org, Michael Roth From: Michael Roth CVE-2013-4533 s->rx_level is read from the wire and used to determine how many bytes to subsequently read into s->rx_fifo[]. If s->rx_level exceeds the length of s->rx_fifo[] the buffer can be overrun with arbitrary data from the wire. Fix this by introducing a constant, RX_FIFO_SZ, that defines the length of s->rx_fifo[], and taking the wire value modulo RX_FIFO_SZ (as is done elsewhere in the emulation code when s->rx_level exceeds RX_FIFO_SZ). Signed-off-by: Michael Roth Signed-off-by: Michael S. Tsirkin --- hw/arm/pxa2xx.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/hw/arm/pxa2xx.c b/hw/arm/pxa2xx.c index 02b7016..41d3c39 100644 --- a/hw/arm/pxa2xx.c +++ b/hw/arm/pxa2xx.c @@ -457,6 +457,8 @@ static const VMStateDescription vmstate_pxa2xx_mm = { } }; +#define RX_FIFO_SZ 16 + #define TYPE_PXA2XX_SSP "pxa2xx-ssp" #define PXA2XX_SSP(obj) \ OBJECT_CHECK(PXA2xxSSPState, (obj), TYPE_PXA2XX_SSP) @@ -481,7 +483,7 @@ typedef struct { uint8_t ssrsa; uint8_t ssacd; - uint32_t rx_fifo[16]; + uint32_t rx_fifo[RX_FIFO_SZ]; int rx_level; int rx_start; } PXA2xxSSPState; @@ -756,7 +758,7 @@ static int pxa2xx_ssp_load(QEMUFile *f, void *opaque, int version_id) qemu_get_8s(f, &s->ssrsa); qemu_get_8s(f, &s->ssacd); - s->rx_level = qemu_get_byte(f); + s->rx_level = qemu_get_byte(f) % RX_FIFO_SZ; s->rx_start = 0; for (i = 0; i < s->rx_level; i ++) s->rx_fifo[i] = qemu_get_byte(f); -- MST