From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40407) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XEuXG-0005ll-Su for qemu-devel@nongnu.org; Wed, 06 Aug 2014 02:17:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XEuXC-0006N3-3U for qemu-devel@nongnu.org; Wed, 06 Aug 2014 02:17:18 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:61376) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XEuXB-0006Is-A5 for qemu-devel@nongnu.org; Wed, 06 Aug 2014 02:17:14 -0400 From: zhanghailiang Date: Wed, 6 Aug 2014 14:15:57 +0800 Message-ID: <1407305758-13108-4-git-send-email-zhang.zhanghailiang@huawei.com> In-Reply-To: <1407305758-13108-1-git-send-email-zhang.zhanghailiang@huawei.com> References: <1407305758-13108-1-git-send-email-zhang.zhanghailiang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [PATCH v2 3/4] virtio-blk: fix reference a pointer which might be freed List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com, mst@redhat.com, luonengjun@huawei.com, peter.huangpeng@huawei.com, lcapitulino@redhat.com, alex@alex.org.uk, pbonzini@redhat.com, alex.bennee@linaro.org, zhanghailiang In function virtio_blk_handle_request, it may freed memory pointed by req, So do not access member of req after calling this function. Reviewed-by: Stefan Hajnoczi Signed-off-by: zhanghailiang --- hw/block/virtio-blk.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index c241c50..54a853a 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -458,7 +458,7 @@ static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) static void virtio_blk_dma_restart_bh(void *opaque) { VirtIOBlock *s = opaque; - VirtIOBlockReq *req = s->rq; + VirtIOBlockReq *req = s->rq, *next = NULL; MultiReqBuffer mrb = { .num_writes = 0, }; @@ -469,8 +469,9 @@ static void virtio_blk_dma_restart_bh(void *opaque) s->rq = NULL; while (req) { + next = req->next; virtio_blk_handle_request(req, &mrb); - req = req->next; + req = next; } virtio_submit_multiwrite(s->bs, &mrb); -- 1.7.12.4