From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45758) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gByXL-0004d4-FB for qemu-devel@nongnu.org; Mon, 15 Oct 2018 04:47:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gByXK-0004ZB-CZ for qemu-devel@nongnu.org; Mon, 15 Oct 2018 04:47:39 -0400 From: Jason Wang Date: Mon, 15 Oct 2018 16:46:23 +0800 Message-Id: <1539593186-32183-24-git-send-email-jasowang@redhat.com> In-Reply-To: <1539593186-32183-1-git-send-email-jasowang@redhat.com> References: <1539593186-32183-1-git-send-email-jasowang@redhat.com> Subject: [Qemu-devel] [PULL 23/26] pcnet: fix possible buffer overflow List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: peter.maydell@linaro.org, qemu-devel@nongnu.org Cc: Jason Wang , qemu-stable@nongnu.org In pcnet_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 for both buf and buf1. Fixing by converting the type of size to size_t. CC: qemu-stable@nongnu.org Reported-by: Daniel Shapira Reviewed-by: Michael S. Tsirkin Signed-off-by: Jason Wang --- hw/net/pcnet.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c index 0c44554..d9ba04b 100644 --- a/hw/net/pcnet.c +++ b/hw/net/pcnet.c @@ -988,14 +988,14 @@ ssize_t pcnet_receive(NetClientState *nc, const uint8_t *buf, size_t size_) uint8_t buf1[60]; int remaining; int crc_err = 0; - int size = size_; + size_t size = size_; if (CSR_DRX(s) || CSR_STOP(s) || CSR_SPND(s) || !size || (CSR_LOOP(s) && !s->looptest)) { return -1; } #ifdef PCNET_DEBUG - printf("pcnet_receive size=%d\n", size); + printf("pcnet_receive size=%zu\n", size); #endif /* if too small buffer, then expand it */ -- 2.5.0