Commit b88fb124 authored by Peter Maydell's avatar Peter Maydell Committed by Jason Wang
Browse files

hw/net/allwinner-sun8i-emac.c: Fix REG_ADDR_HIGH/LOW reads 



Coverity points out (CID 1421926) that the read code for
REG_ADDR_HIGH reads off the end of the buffer, because it does a
32-bit read from byte 4 of a 6-byte buffer.

The code also has an endianness issue for both REG_ADDR_HIGH and
REG_ADDR_LOW, because it will do the wrong thing on a big-endian
host.

Rewrite the read code to use ldl_le_p() and lduw_le_p() to fix this;
the write code is not incorrect, but for consistency we make it use
stl_le_p() and stw_le_p().

Reviewed-by: default avatarRichard Henderson <richard.henderson@linaro.org>
Tested-by: default avatarNiek Linnenbank <nieklinnenbank@gmail.com>
Reviewed-by: default avatarNiek Linnenbank <nieklinnenbank@gmail.com>
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
parent 8ffb7265

hw/net/allwinner-sun8i-emac.c

+4 −8
Original line number Diff line number Diff line
@@ -611,10 +611,10 @@ static uint64_t allwinner_sun8i_emac_read(void *opaque, hwaddr offset, 
        value = s->mii_data;

        break;

    case REG_ADDR_HIGH:         /* MAC Address High */

        value = *(((uint32_t *) (s->conf.macaddr.a)) + 1);

        value = lduw_le_p(s->conf.macaddr.a + 4);

        break;

    case REG_ADDR_LOW:          /* MAC Address Low */

        value = *(uint32_t *) (s->conf.macaddr.a);

        value = ldl_le_p(s->conf.macaddr.a);

        break;

    case REG_TX_DMA_STA:        /* Transmit DMA Status */

        break;
@@ -728,14 +728,10 @@ static void allwinner_sun8i_emac_write(void *opaque, hwaddr offset, 
        s->mii_data = value;

        break;

    case REG_ADDR_HIGH:         /* MAC Address High */

        s->conf.macaddr.a[4] = (value & 0xff);

        s->conf.macaddr.a[5] = (value & 0xff00) >> 8;

        stw_le_p(s->conf.macaddr.a + 4, value);

        break;

    case REG_ADDR_LOW:          /* MAC Address Low */

        s->conf.macaddr.a[0] = (value & 0xff);

        s->conf.macaddr.a[1] = (value & 0xff00) >> 8;

        s->conf.macaddr.a[2] = (value & 0xff0000) >> 16;

        s->conf.macaddr.a[3] = (value & 0xff000000) >> 24;

        stl_le_p(s->conf.macaddr.a, value);

        break;

    case REG_TX_DMA_STA:        /* Transmit DMA Status */

    case REG_TX_CUR_DESC:       /* Transmit Current Descriptor */