From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51412) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aDVRU-0000Uh-IX for qemu-devel@nongnu.org; Mon, 28 Dec 2015 05:54:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aDVRR-0004Gn-CY for qemu-devel@nongnu.org; Mon, 28 Dec 2015 05:54:20 -0500 From: P J P Date: Mon, 28 Dec 2015 16:24:08 +0530 Message-Id: <1451300048-27254-1-git-send-email-ppandit@redhat.com> Subject: [Qemu-devel] [PATCH v2] net: rocker: fix an incorrect array bounds check List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jason Wang Cc: Peter Maydell , Jiri Pirko , Prasad J Pandit , QEMU Developers , qemu-stable@nongnu.org, Qinghao Tang , Scott Feldman , Paolo Bonzini From: Prasad J Pandit While processing transmit(tx) descriptors in 'tx_consume' routine the switch emulator suffers from an off-by-one error, if a descriptor was to have more than allowed(ROCKER_TX_FRAGS_MAX=16) fragments. Fix an incorrect bounds check to avoid it. Reported-by: Qinghao Tang Signed-off-by: Prasad J Pandit --- hw/net/rocker/rocker.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/hw/net/rocker/rocker.c b/hw/net/rocker/rocker.c index c57f1a6..2e77e50 100644 --- a/hw/net/rocker/rocker.c +++ b/hw/net/rocker/rocker.c @@ -232,6 +232,9 @@ static int tx_consume(Rocker *r, DescInfo *info) frag_addr = rocker_tlv_get_le64(tlvs[ROCKER_TLV_TX_FRAG_ATTR_ADDR]); frag_len = rocker_tlv_get_le16(tlvs[ROCKER_TLV_TX_FRAG_ATTR_LEN]); + if (iovcnt >= ROCKER_TX_FRAGS_MAX) { + goto err_too_many_frags; + } iov[iovcnt].iov_len = frag_len; iov[iovcnt].iov_base = g_malloc(frag_len); if (!iov[iovcnt].iov_base) { @@ -244,10 +247,7 @@ static int tx_consume(Rocker *r, DescInfo *info) err = -ROCKER_ENXIO; goto err_bad_io; } - - if (++iovcnt > ROCKER_TX_FRAGS_MAX) { - goto err_too_many_frags; - } + iovcnt++; } if (iovcnt) { -- 2.4.3