P J P <ppan...@redhat.com> 于2020年3月25日周三 上午1:31写道：
> From: Prasad J Pandit <p...@fedoraproject.org> > > Tulip network driver while copying tx/rx buffers does not check > frame size against r/w data length. This may lead to OOB buffer > access. Add check to avoid it. > > Limit iterations over descriptors to avoid potential infinite > loop issue in tulip_xmit_list_update. > > Reported-by: Li Qiang <pangpei...@antfin.com> > Reported-by: Ziming Zhang <ezrak...@gmail.com> > Reported-by: Jason Wang <jasow...@redhat.com> > Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> > Tested-by: Li Qiang <liq...@gmail.com> Reviewed-by: Li Qiang <liq...@gmail.com> Thanks, Li Qiang > --- > hw/net/tulip.c | 36 +++++++++++++++++++++++++++--------- > 1 file changed, 27 insertions(+), 9 deletions(-) > > Update v7: fix length check expression to replace '>=' with '>' > -> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg07160.html > > diff --git a/hw/net/tulip.c b/hw/net/tulip.c > index cfac2719d3..1295f51d07 100644 > --- a/hw/net/tulip.c > +++ b/hw/net/tulip.c > @@ -170,6 +170,10 @@ static void tulip_copy_rx_bytes(TULIPState *s, struct > tulip_descriptor *desc) > } else { > len = s->rx_frame_len; > } > + > + if (s->rx_frame_len + len > sizeof(s->rx_frame)) { > + return; > + } > pci_dma_write(&s->dev, desc->buf_addr1, s->rx_frame + > (s->rx_frame_size - s->rx_frame_len), len); > s->rx_frame_len -= len; > @@ -181,6 +185,10 @@ static void tulip_copy_rx_bytes(TULIPState *s, struct > tulip_descriptor *desc) > } else { > len = s->rx_frame_len; > } > + > + if (s->rx_frame_len + len > sizeof(s->rx_frame)) { > + return; > + } > pci_dma_write(&s->dev, desc->buf_addr2, s->rx_frame + > (s->rx_frame_size - s->rx_frame_len), len); > s->rx_frame_len -= len; > @@ -227,7 +235,8 @@ static ssize_t tulip_receive(TULIPState *s, const > uint8_t *buf, size_t size) > > trace_tulip_receive(buf, size); > > - if (size < 14 || size > 2048 || s->rx_frame_len || > tulip_rx_stopped(s)) { > + if (size < 14 || size > sizeof(s->rx_frame) - 4 > + || s->rx_frame_len || tulip_rx_stopped(s)) { > return 0; > } > > @@ -275,7 +284,6 @@ static ssize_t tulip_receive_nc(NetClientState *nc, > return tulip_receive(qemu_get_nic_opaque(nc), buf, size); > } > > - > static NetClientInfo net_tulip_info = { > .type = NET_CLIENT_DRIVER_NIC, > .size = sizeof(NICState), > @@ -558,7 +566,7 @@ static void tulip_tx(TULIPState *s, struct > tulip_descriptor *desc) > if ((s->csr[6] >> CSR6_OM_SHIFT) & CSR6_OM_MASK) { > /* Internal or external Loopback */ > tulip_receive(s, s->tx_frame, s->tx_frame_len); > - } else { > + } else if (s->tx_frame_len <= sizeof(s->tx_frame)) { > qemu_send_packet(qemu_get_queue(s->nic), > s->tx_frame, s->tx_frame_len); > } > @@ -570,23 +578,31 @@ static void tulip_tx(TULIPState *s, struct > tulip_descriptor *desc) > } > } > > -static void tulip_copy_tx_buffers(TULIPState *s, struct tulip_descriptor > *desc) > +static int tulip_copy_tx_buffers(TULIPState *s, struct tulip_descriptor > *desc) > { > int len1 = (desc->control >> TDES1_BUF1_SIZE_SHIFT) & > TDES1_BUF1_SIZE_MASK; > int len2 = (desc->control >> TDES1_BUF2_SIZE_SHIFT) & > TDES1_BUF2_SIZE_MASK; > > + if (s->tx_frame_len + len1 > sizeof(s->tx_frame)) { > + return -1; > + } > if (len1) { > pci_dma_read(&s->dev, desc->buf_addr1, > s->tx_frame + s->tx_frame_len, len1); > s->tx_frame_len += len1; > } > > + if (s->tx_frame_len + len2 > sizeof(s->tx_frame)) { > + return -1; > + } > if (len2) { > pci_dma_read(&s->dev, desc->buf_addr2, > s->tx_frame + s->tx_frame_len, len2); > s->tx_frame_len += len2; > } > desc->status = (len1 + len2) ? 0 : 0x7fffffff; > + > + return 0; > } > > static void tulip_setup_filter_addr(TULIPState *s, uint8_t *buf, int n) > @@ -651,13 +667,15 @@ static uint32_t tulip_ts(TULIPState *s) > > static void tulip_xmit_list_update(TULIPState *s) > { > +#define TULIP_DESC_MAX 128 > + uint8_t i = 0; > struct tulip_descriptor desc; > > if (tulip_ts(s) != CSR5_TS_SUSPENDED) { > return; > } > > - for (;;) { > + for (i = 0; i < TULIP_DESC_MAX; i++) { > tulip_desc_read(s, s->current_tx_desc, &desc); > tulip_dump_tx_descriptor(s, &desc); > > @@ -675,10 +693,10 @@ static void tulip_xmit_list_update(TULIPState *s) > s->tx_frame_len = 0; > } > > - tulip_copy_tx_buffers(s, &desc); > - > - if (desc.control & TDES1_LS) { > - tulip_tx(s, &desc); > + if (!tulip_copy_tx_buffers(s, &desc)) { > + if (desc.control & TDES1_LS) { > + tulip_tx(s, &desc); > + } > } > } > tulip_desc_write(s, s->current_tx_desc, &desc); > -- > 2.25.1 > > >
