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| author | Michael S. Tsirkin <mst@redhat.com> | 2016-01-14 11:43:30 +0200 |
|---|---|---|
| committer | Jason Wang <jasowang@redhat.com> | 2016-02-04 13:22:06 +0800 |
| commit | d7f053652fef48bee7c461c162c8d4d2c96ab157 (patch) | |
| tree | 3f330b046e6102caf7fabb18ede347802630419e | |
| parent | 244381ec19ce1412b474f41b5f30fe1da846451b (diff) | |
| download | qemu-d7f053652fef48bee7c461c162c8d4d2c96ab157.zip qemu-d7f053652fef48bee7c461c162c8d4d2c96ab157.tar.gz qemu-d7f053652fef48bee7c461c162c8d4d2c96ab157.tar.bz2 | |
cadence_gem: fix buffer overflow
gem_transmit copies a packet from guest into an tx_packet[2048]
array on stack, with size limited by descriptor length set by guest. If
guest is malicious and specifies a descriptor length that is too large,
and should packet size exceed array size, this results in a buffer
overflow.
Reported-by: 刘令 <liuling-it@360.cn>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
| -rw-r--r-- | hw/net/cadence_gem.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c index e513d9d..0346f3e 100644 --- a/hw/net/cadence_gem.c +++ b/hw/net/cadence_gem.c @@ -867,6 +867,14 @@ static void gem_transmit(CadenceGEMState *s) break; } + if (tx_desc_get_length(desc) > sizeof(tx_packet) - (p - tx_packet)) { + DB_PRINT("TX descriptor @ 0x%x too large: size 0x%x space 0x%x\n", + (unsigned)packet_desc_addr, + (unsigned)tx_desc_get_length(desc), + sizeof(tx_packet) - (p - tx_packet)); + break; + } + /* Gather this fragment of the packet from "dma memory" to our contig. * buffer. */ |