From: chaojianhu Date: Tue, 9 Aug 2016 11:52:54 +0800 Subject: [PATCH] hw/net: Fix a heap overflow in xlnx.xps-ethernetlite The .receive callback of xlnx.xps-ethernetlite doesn't check the length of data before calling memcpy. As a result, the NetClientState object in heap will be overflowed. All versions of qemu with xlnx.xps-ethernetlite will be affected. Reported-by: chaojianhu Signed-off-by: chaojianhu Signed-off-by: Jason Wang (cherry picked from commit a0d1cbdacff5df4ded16b753b38fdd9da6092968) --- hw/net/xilinx_ethlite.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/hw/net/xilinx_ethlite.c b/hw/net/xilinx_ethlite.c index bc846e7..12b7419 100644 --- a/hw/net/xilinx_ethlite.c +++ b/hw/net/xilinx_ethlite.c @@ -197,6 +197,10 @@ static ssize_t eth_rx(NetClientState *nc, const uint8_t *buf, size_t size) } D(qemu_log("%s %zd rxbase=%x\n", __func__, size, rxbase)); + if (size > (R_MAX - R_RX_BUF0 - rxbase) * 4) { + D(qemu_log("ethlite packet is too big, size=%x\n", size)); + return -1; + } memcpy(&s->regs[rxbase + R_RX_BUF0], buf, size); s->regs[rxbase + R_RX_CTRL0] |= CTRL_S;