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Re: [Qemu-devel] [PATCH v2] net: rocker: fix an incorrect array bounds c
From: |
Jason Wang |
Subject: |
Re: [Qemu-devel] [PATCH v2] net: rocker: fix an incorrect array bounds check |
Date: |
Tue, 29 Dec 2015 10:24:02 +0800 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 |
On 12/28/2015 06:54 PM, P J P wrote:
> From: Prasad J Pandit <address@hidden>
>
> 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 <address@hidden>
> Signed-off-by: Prasad J Pandit <address@hidden>
> ---
> 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) {
Applied in my -net.
Thanks