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[v7] virtio-blk: fix reference a pointer which might be freed

Message ID 1408347771-10596-1-git-send-email-zhang.zhanghailiang@huawei.com
State New
Headers show

Commit Message

Zhanghailiang Aug. 18, 2014, 7:42 a.m. UTC 
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: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
---
 hw/block/virtio-blk.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Paolo Bonzini Aug. 18, 2014, 8:08 a.m. UTC | #1 
Il 18/08/2014 09:42, zhanghailiang ha scritto:
> 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: Michael S. Tsirkin <mst@redhat.com>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> ---
>  hw/block/virtio-blk.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> index c241c50..0e3925b 100644
> --- a/hw/block/virtio-blk.c
> +++ b/hw/block/virtio-blk.c
> @@ -469,8 +469,9 @@ static void virtio_blk_dma_restart_bh(void *opaque)
>      s->rq = NULL;
>  
>      while (req) {
> +        VirtIOBlockReq *next = req->next;
>          virtio_blk_handle_request(req, &mrb);
> -        req = req->next;
> +        req = next;
>      }
>  
>      virtio_submit_multiwrite(s->bs, &mrb);
> 

Cc: qemu-stable@nongnu.org
Kevin Wolf Aug. 20, 2014, 9:58 a.m. UTC | #2 
Am 18.08.2014 um 10:08 hat Paolo Bonzini geschrieben:
> Il 18/08/2014 09:42, zhanghailiang ha scritto:
> > 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: Michael S. Tsirkin <mst@redhat.com>
> > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> > Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> 
> Cc: qemu-stable@nongnu.org

Thanks, added the Cc: line and applied to the block branch.

Kevin
diff mbox

Patch

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index c241c50..0e3925b 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -469,8 +469,9 @@  static void virtio_blk_dma_restart_bh(void *opaque)
     s->rq = NULL;
 
     while (req) {
+        VirtIOBlockReq *next = req->next;
         virtio_blk_handle_request(req, &mrb);
-        req = req->next;
+        req = next;
     }
 
     virtio_submit_multiwrite(s->bs, &mrb);