From 20abe443ad9464b18ac494f71f7d53f19ee3748f Mon Sep 17 00:00:00 2001 From: Changqing Li Date: Mon, 15 Oct 2018 16:38:08 +0800 Subject: [PATCH] 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: address@hidden Reported-by: Daniel Shapira Reviewed-by: Michael S. Tsirkin Signed-off-by: Jason Wang Upstream-Status: Backport [https://lists.gnu.org/archive/html/qemu-devel/2018-09/msg03269.html] CVE: CVE-2018-17962 Signed-off-by: Changqing Li --- hw/net/rtl8139.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/hw/net/rtl8139.c b/hw/net/rtl8139.c index 46daa16..2342a09 100644 --- a/hw/net/rtl8139.c +++ b/hw/net/rtl8139.c @@ -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; -- 2.7.4