From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=36253 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OYNCJ-0003FG-9G for qemu-devel@nongnu.org; Mon, 12 Jul 2010 13:53:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OYNCI-0007m1-3A for qemu-devel@nongnu.org; Mon, 12 Jul 2010 13:53:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:14982) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OYNCH-0007lw-SV for qemu-devel@nongnu.org; Mon, 12 Jul 2010 13:53:42 -0400 Date: Mon, 12 Jul 2010 20:48:24 +0300 From: "Michael S. Tsirkin" Message-ID: <20100712174823.GA11411@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Subject: [Qemu-devel] [PATCH RFC] e1000: fix access 4 bytes beyond buffer end List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori , qemu-devel@nongnu.org, alex.williamson@redhat.com We do range check for size, and get size as buffer, but copy size + 4 bytes (4 is for FCS). Let's copy size bytes but put size + 4 in length. Signed-off-by: Michael S. Tsirkin --- Anthony, Alex, please review. hw/e1000.c | 3 +-- 1 files changed, 1 insertions(+), 2 deletions(-) diff --git a/hw/e1000.c b/hw/e1000.c index 0da65f9..70aba11 100644 --- a/hw/e1000.c +++ b/hw/e1000.c @@ -649,7 +649,6 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size) } rdh_start = s->mac_reg[RDH]; - size += 4; // for the header do { if (s->mac_reg[RDH] == s->mac_reg[RDT] && s->check_rxov) { set_ics(s, 0, E1000_ICS_RXO); @@ -663,7 +662,7 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size) if (desc.buffer_addr) { cpu_physical_memory_write(le64_to_cpu(desc.buffer_addr), (void *)(buf + vlan_offset), size); - desc.length = cpu_to_le16(size); + desc.length = cpu_to_le16(size + 4 /* for FCS */); desc.status |= E1000_RXD_STAT_EOP|E1000_RXD_STAT_IXSM; } else // as per intel docs; skip descriptors with null buf addr DBGOUT(RX, "Null RX descriptor!!\n"); -- 1.7.2.rc0.14.g41c1c