From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48428) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aJyNT-0006PQ-Ks for qemu-devel@nongnu.org; Fri, 15 Jan 2016 02:00:56 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aJyNS-0000zB-Rp for qemu-devel@nongnu.org; Fri, 15 Jan 2016 02:00:55 -0500 From: P J P Date: Fri, 15 Jan 2016 12:30:40 +0530 Message-Id: <1452841240-30377-1-git-send-email-ppandit@redhat.com> Subject: [Qemu-devel] [PATCH] net: cadence_gem: check packet size in gem_recieve List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: QEMU Developers Cc: Jason Wang , qemu-arm , Prasad J Pandit , Ling Liu , "Michael S. Tsirkin" From: Prasad J Pandit While receiving packets in 'gem_receive' routine, if Frame Check Sequence(FCS) is enabled, it copies the packet into a local buffer without checking its size. Add check to validate packet length against the buffer size to avoid buffer overflow. Reported-by: Ling Liu Signed-off-by: Prasad J Pandit --- hw/net/cadence_gem.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c index 3639fc1..c3a273b 100644 --- a/hw/net/cadence_gem.c +++ b/hw/net/cadence_gem.c @@ -677,10 +677,14 @@ static ssize_t gem_receive(NetClientState *nc, const uint8_t *buf, size_t size) } else { unsigned crc_val; + if (size > sizeof(rxbuf) - sizeof(crc_val)) { + size = sizeof(rxbuf) - sizeof(crc_val); + } + bytes_to_copy = size; + /* The application wants the FCS field, which QEMU does not provide. * We must try and calculate one. */ - memcpy(rxbuf, buf, size); memset(rxbuf + size, 0, sizeof(rxbuf) - size); rxbuf_ptr = rxbuf; -- 2.5.0