| Message ID | 1383728288-28469-1-git-send-email-jasowang@redhat.com |
|---|---|
| State | New |
| Headers | show |
Il 06/11/2013 09:58, Jason Wang ha scritto: > We delete without check whether it existed during exit. This will lead NULL > pointer deference since it was created conditionally depends on guest driver > status and features. So add a check of existence before trying to delete it. > > Cc: qemu-stable@nongnu.org > Signed-off-by: Jason Wang <jasowang@redhat.com> > --- > hw/net/virtio-net.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c > index 22dbd05..ae51d96 100644 > --- a/hw/net/virtio-net.c > +++ b/hw/net/virtio-net.c > @@ -1601,7 +1601,7 @@ static int virtio_net_device_exit(DeviceState *qdev) > if (q->tx_timer) { > timer_del(q->tx_timer); > timer_free(q->tx_timer); > - } else { > + } else if (q->tx_bh) { > qemu_bh_delete(q->tx_bh); > } > } > Please remember to add 1.7 in the subject at this time. Paolo
On Wed, Nov 06, 2013 at 04:58:08PM +0800, Jason Wang wrote: > We delete without check whether it existed during exit. This will lead NULL > pointer deference since it was created conditionally depends on guest driver > status and features. So add a check of existence before trying to delete it. > > Cc: qemu-stable@nongnu.org > Signed-off-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Looks like the bug was introduced by: commit 17ec5a8686143da66208273d355f2eeb09807614 Author: KONRAD Frederic <fred.konrad@greensocs.com> Date: Thu Apr 11 16:29:57 2013 +0200 virtio-net: add the virtio-net device. Before that we had a single bh and created/destroyed that unconditionally. Is this a correct analysis? > --- > hw/net/virtio-net.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c > index 22dbd05..ae51d96 100644 > --- a/hw/net/virtio-net.c > +++ b/hw/net/virtio-net.c > @@ -1601,7 +1601,7 @@ static int virtio_net_device_exit(DeviceState *qdev) > if (q->tx_timer) { > timer_del(q->tx_timer); > timer_free(q->tx_timer); > - } else { > + } else if (q->tx_bh) { > qemu_bh_delete(q->tx_bh); > } > } > -- > 1.8.3.2
On 11/06/2013 07:17 PM, Michael S. Tsirkin wrote: > On Wed, Nov 06, 2013 at 04:58:08PM +0800, Jason Wang wrote: >> We delete without check whether it existed during exit. This will lead NULL >> pointer deference since it was created conditionally depends on guest driver >> status and features. So add a check of existence before trying to delete it. >> >> Cc: qemu-stable@nongnu.org >> Signed-off-by: Jason Wang <jasowang@redhat.com> > Reviewed-by: Michael S. Tsirkin <mst@redhat.com> > > Looks like the bug was introduced by: > commit 17ec5a8686143da66208273d355f2eeb09807614 > Author: KONRAD Frederic <fred.konrad@greensocs.com> > Date: Thu Apr 11 16:29:57 2013 +0200 > virtio-net: add the virtio-net device. > > Before that we had a single bh and created/destroyed > that unconditionally. > Is this a correct analysis? > Nope, it was introduced in the multiqueue virito-net, since the bh were created conditionally from that commit. commit fed699f9ca6ae8a0fb62803334cf46fa64d1eb91 Author: Jason Wang <jasowang@redhat.com> Date: Wed Jan 30 19:12:39 2013 +0800 virtio-net: multiqueue support > >> --- >> hw/net/virtio-net.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c >> index 22dbd05..ae51d96 100644 >> --- a/hw/net/virtio-net.c >> +++ b/hw/net/virtio-net.c >> @@ -1601,7 +1601,7 @@ static int virtio_net_device_exit(DeviceState *qdev) >> if (q->tx_timer) { >> timer_del(q->tx_timer); >> timer_free(q->tx_timer); >> - } else { >> + } else if (q->tx_bh) { >> qemu_bh_delete(q->tx_bh); >> } >> } >> -- >> 1.8.3.2
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 22dbd05..ae51d96 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -1601,7 +1601,7 @@ static int virtio_net_device_exit(DeviceState *qdev) if (q->tx_timer) { timer_del(q->tx_timer); timer_free(q->tx_timer); - } else { + } else if (q->tx_bh) { qemu_bh_delete(q->tx_bh); } }
We delete without check whether it existed during exit. This will lead NULL pointer deference since it was created conditionally depends on guest driver status and features. So add a check of existence before trying to delete it. Cc: qemu-stable@nongnu.org Signed-off-by: Jason Wang <jasowang@redhat.com> --- hw/net/virtio-net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)