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Re: [Qemu-devel] [PATCH v2 for-2.2 3/4] pcnet: fix Negative array index
From: |
Jason Wang |
Subject: |
Re: [Qemu-devel] [PATCH v2 for-2.2 3/4] pcnet: fix Negative array index read |
Date: |
Fri, 21 Nov 2014 09:42:05 +0800 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 |
On 11/20/2014 07:35 PM, address@hidden wrote:
> From: Gonglei <address@hidden>
>
> s->xmit_pos maybe assigned to a negative value (-1),
> but in this branch variable s->xmit_pos as an index to
> array s->buffer. Let's add a check for s->xmit_pos.
>
> Signed-off-by: Gonglei <address@hidden>
> Signed-off-by: Paolo Bonzini <address@hidden>
> Reviewed-by: Jason Wang <address@hidden>
> ---
> hw/net/pcnet.c | 55 ++++++++++++++++++++++++++++++-------------------------
> 1 file changed, 30 insertions(+), 25 deletions(-)
>
> diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c
> index d344c15..f409b92 100644
> --- a/hw/net/pcnet.c
> +++ b/hw/net/pcnet.c
> @@ -1212,7 +1212,7 @@ static void pcnet_transmit(PCNetState *s)
> hwaddr xmit_cxda = 0;
> int count = CSR_XMTRL(s)-1;
> int add_crc = 0;
> -
> + int bcnt;
> s->xmit_pos = -1;
>
> if (!CSR_TXON(s)) {
> @@ -1247,35 +1247,40 @@ static void pcnet_transmit(PCNetState *s)
> s->xmit_pos = -1;
> goto txdone;
> }
> +
> + if (s->xmit_pos < 0) {
> + goto txdone;
> + }
> +
> + bcnt = 4096 - GET_FIELD(tmd.length, TMDL, BCNT);
> + s->phys_mem_read(s->dma_opaque, PHYSADDR(s, tmd.tbadr),
> + s->buffer + s->xmit_pos, bcnt, CSR_BSWP(s));
> + s->xmit_pos += bcnt;
> +
> if (!GET_FIELD(tmd.status, TMDS, ENP)) {
> - int bcnt = 4096 - GET_FIELD(tmd.length, TMDL, BCNT);
> - s->phys_mem_read(s->dma_opaque, PHYSADDR(s, tmd.tbadr),
> - s->buffer + s->xmit_pos, bcnt, CSR_BSWP(s));
> - s->xmit_pos += bcnt;
> - } else if (s->xmit_pos >= 0) {
> - int bcnt = 4096 - GET_FIELD(tmd.length, TMDL, BCNT);
> - s->phys_mem_read(s->dma_opaque, PHYSADDR(s, tmd.tbadr),
> - s->buffer + s->xmit_pos, bcnt, CSR_BSWP(s));
> - s->xmit_pos += bcnt;
> + goto txdone;
> + }
> +
> #ifdef PCNET_DEBUG
> - printf("pcnet_transmit size=%d\n", s->xmit_pos);
> + printf("pcnet_transmit size=%d\n", s->xmit_pos);
> #endif
> - if (CSR_LOOP(s)) {
> - if (BCR_SWSTYLE(s) == 1)
> - add_crc = !GET_FIELD(tmd.status, TMDS, NOFCS);
> - s->looptest = add_crc ? PCNET_LOOPTEST_CRC :
> PCNET_LOOPTEST_NOCRC;
> - pcnet_receive(qemu_get_queue(s->nic), s->buffer,
> s->xmit_pos);
> - s->looptest = 0;
> - } else
> - if (s->nic)
> - qemu_send_packet(qemu_get_queue(s->nic), s->buffer,
> - s->xmit_pos);
> -
> - s->csr[0] &= ~0x0008; /* clear TDMD */
> - s->csr[4] |= 0x0004; /* set TXSTRT */
> - s->xmit_pos = -1;
> + if (CSR_LOOP(s)) {
> + if (BCR_SWSTYLE(s) == 1)
> + add_crc = !GET_FIELD(tmd.status, TMDS, NOFCS);
> + s->looptest = add_crc ? PCNET_LOOPTEST_CRC :
> PCNET_LOOPTEST_NOCRC;
> + pcnet_receive(qemu_get_queue(s->nic), s->buffer, s->xmit_pos);
> + s->looptest = 0;
> + } else {
> + if (s->nic) {
> + qemu_send_packet(qemu_get_queue(s->nic), s->buffer,
> + s->xmit_pos);
> + }
> }
>
> + s->csr[0] &= ~0x0008; /* clear TDMD */
> + s->csr[4] |= 0x0004; /* set TXSTRT */
> + s->xmit_pos = -1;
> +
> txdone:
> SET_FIELD(&tmd.status, TMDS, OWN, 0);
> TMDSTORE(&tmd, PHYSADDR(s,CSR_CXDA(s)));
Reviewed-by: Jason Wang <address@hidden>
- [Qemu-devel] [PATCH v2 for-2.2 0/4] net: fix high impact outstanding defects reported by Coverity, arei.gonglei, 2014/11/20
- [Qemu-devel] [PATCH v2 for-2.2 1/4] net/slirp: fix memory leak, arei.gonglei, 2014/11/20
- [Qemu-devel] [PATCH v2 for-2.2 2/4] net/socket: fix Uninitialized scalar variable, arei.gonglei, 2014/11/20
- [Qemu-devel] [PATCH v2 for-2.2 4/4] rtl8139: fix Pointer to local outside scope, arei.gonglei, 2014/11/20
- [Qemu-devel] [PATCH v2 for-2.2 3/4] pcnet: fix Negative array index read, arei.gonglei, 2014/11/20
- Re: [Qemu-devel] [PATCH v2 for-2.2 3/4] pcnet: fix Negative array index read,
Jason Wang <=
- Re: [Qemu-devel] [PATCH v2 for-2.2 0/4] net: fix high impact outstanding defects reported by Coverity, Paolo Bonzini, 2014/11/20