Commit 1a326646 authored by Jason Wang's avatar Jason Wang
Browse files

rtl8139: fix possible out of bound access 



In rtl8139_do_receive(), we try to assign size_ to size which converts
from size_t to integer. This will cause troubles when size_ is greater
INT_MAX, this will lead a negative value in size and it can then pass
the check of size < MIN_BUF_SIZE which may lead out of bound access of
for both buf and buf1.

Fixing by converting the type of size to size_t.

CC: qemu-stable@nongnu.org
Reported-by: default avatarDaniel Shapira <daniel@twistlock.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
parent fdc89e90

hw/net/rtl8139.c

+4 −4
Original line number Diff line number Diff line
@@ -817,7 +817,7 @@ static ssize_t rtl8139_do_receive(NetClientState *nc, const uint8_t *buf, size_t 
    RTL8139State *s = qemu_get_nic_opaque(nc);

    PCIDevice *d = PCI_DEVICE(s);

    /* size is the length of the buffer passed to the driver */

    int size = size_;

    size_t size = size_;

    const uint8_t *dot1q_buf = NULL;



    uint32_t packet_header = 0;
@@ -826,7 +826,7 @@ static ssize_t rtl8139_do_receive(NetClientState *nc, const uint8_t *buf, size_t 
    static const uint8_t broadcast_macaddr[6] =

        { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };



    DPRINTF(">>> received len=%d\n", size);

    DPRINTF(">>> received len=%zu\n", size);



    /* test if board clock is stopped */

    if (!s->clock_enabled)
@@ -1035,7 +1035,7 @@ static ssize_t rtl8139_do_receive(NetClientState *nc, const uint8_t *buf, size_t 


        if (size+4 > rx_space)

        {

            DPRINTF("C+ Rx mode : descriptor %d size %d received %d + 4\n",

            DPRINTF("C+ Rx mode : descriptor %d size %d received %zu + 4\n",

                descriptor, rx_space, size);



            s->IntrStatus |= RxOverflow;
@@ -1148,7 +1148,7 @@ static ssize_t rtl8139_do_receive(NetClientState *nc, const uint8_t *buf, size_t 
        if (avail != 0 && RX_ALIGN(size + 8) >= avail)

        {

            DPRINTF("rx overflow: rx buffer length %d head 0x%04x "

                "read 0x%04x === available 0x%04x need 0x%04x\n",

                "read 0x%04x === available 0x%04x need 0x%04zx\n",

                s->RxBufferSize, s->RxBufAddr, s->RxBufPtr, avail, size + 8);



            s->IntrStatus |= RxOverflow;