From: Prasad J Pandit Date: Mon, 28 Dec 2015 16:24:08 +0530 Subject: [PATCH] net: rocker: fix an incorrect array bounds check 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 Cc: qemu-stable@nongnu.org Signed-off-by: Prasad J Pandit Signed-off-by: Jason Wang (cherry picked from commit 007cd223de527b5f41278f2d886c1a4beb3e67aa) --- 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) {