From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51260) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gSCuL-0006WH-5m for qemu-devel@nongnu.org; Wed, 28 Nov 2018 22:22:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gSCky-0006sX-LC for qemu-devel@nongnu.org; Wed, 28 Nov 2018 22:12:50 -0500 From: Jason Wang Date: Thu, 29 Nov 2018 11:12:27 +0800 Message-Id: <20181129031230.31082-2-jasowang@redhat.com> In-Reply-To: <20181129031230.31082-1-jasowang@redhat.com> References: <20181129031230.31082-1-jasowang@redhat.com> Subject: [Qemu-devel] [PATCH for 3.1 1/4] net: drop too large packet early List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, peter.maydell@linaro.org Cc: mst@redhat.com, ppandit@redhat.com, liq3ea@163.com, liq3ea@gmail.com, pbonzini@redhat.com, Jason Wang , qemu-stable@nongnu.org We try to detect and drop too large packet (>INT_MAX) in 1592a9947036 ("net: ignore packet size greater than INT_MAX") during packet delivering. Unfortunately, this is not sufficient as we may hit another integer overflow when trying to queue such large packet in qemu_net_queue_append_iov(): - size of the allocation may overflow on 32bit - packet->size is integer which may overflow even on 64bit Fixing this by move the check to qemu_sendv_packet_async() which is the entrance of all networking codes and reduce the limit to NET_BUFSIZE to be more conservative. Cc: qemu-stable@nongnu.org Cc: Li Qiang Reported-by: Li Qiang Signed-off-by: Jason Wang --- net/net.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/net/net.c b/net/net.c index 07c194a8f6..affe1877cf 100644 --- a/net/net.c +++ b/net/net.c @@ -712,15 +712,11 @@ ssize_t qemu_deliver_packet_iov(NetClientState *sender, void *opaque) { NetClientState *nc = opaque; - size_t size = iov_size(iov, iovcnt); int ret; - if (size > INT_MAX) { - return size; - } if (nc->link_down) { - return size; + return iov_size(iov, iovcnt); } if (nc->receive_disabled) { @@ -745,10 +741,15 @@ ssize_t qemu_sendv_packet_async(NetClientState *sender, NetPacketSent *sent_cb) { NetQueue *queue; + size_t size = iov_size(iov, iovcnt); int ret; + if (size > NET_BUFSIZE) { + return size; + } + if (sender->link_down || !sender->peer) { - return iov_size(iov, iovcnt); + return size; } /* Let filters handle the packet first */ -- 2.17.1