From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39968) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XEDbA-0002kU-Hg for qemu-devel@nongnu.org; Mon, 04 Aug 2014 04:26:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XEDb3-00075v-CP for qemu-devel@nongnu.org; Mon, 04 Aug 2014 04:26:28 -0400 Received: from szxga01-in.huawei.com ([119.145.14.64]:24111) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XEDb2-0006yU-LI for qemu-devel@nongnu.org; Mon, 04 Aug 2014 04:26:21 -0400 From: zhanghailiang Date: Mon, 4 Aug 2014 16:25:43 +0800 Message-ID: <1407140744-11948-4-git-send-email-zhang.zhanghailiang@huawei.com> In-Reply-To: <1407140744-11948-1-git-send-email-zhang.zhanghailiang@huawei.com> References: <1407140744-11948-1-git-send-email-zhang.zhanghailiang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [PATCH 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, 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. 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