| Message ID | 1522155052-13347-1-git-send-email-jasowang@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Mar 27, 2018 at 08:50:52PM +0800, Jason Wang wrote: >We tried to remove vq poll from wait queue, but do not check whether >or not it was in a list before. This will lead double free. Fixing >this by switching to use vhost_poll_stop() which zeros poll->wqh after >removing poll from waitqueue to make sure it won't be freed twice. > >Cc: Darren Kenny <darren.kenny@oracle.com> >Reported-by: syzbot+c0272972b01b872e604a@syzkaller.appspotmail.com >Fixes: 2b8b328b61c79 ("vhost_net: handle polling errors when setting backend") >Signed-off-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> >--- >Changes from V1: >- tweak the commit log for to match the code >--- > drivers/vhost/vhost.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > >diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c >index 1b3e8d2d..5d5a9d9 100644 >--- a/drivers/vhost/vhost.c >+++ b/drivers/vhost/vhost.c >@@ -212,8 +212,7 @@ int vhost_poll_start(struct vhost_poll *poll, struct file *file) > if (mask) > vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask)); > if (mask & EPOLLERR) { >- if (poll->wqh) >- remove_wait_queue(poll->wqh, &poll->wait); >+ vhost_poll_stop(poll); > ret = -EINVAL; > } > >-- >2.7.4 >
On Tue, Mar 27, 2018 at 08:50:52PM +0800, Jason Wang wrote: > We tried to remove vq poll from wait queue, but do not check whether > or not it was in a list before. This will lead double free. Fixing > this by switching to use vhost_poll_stop() which zeros poll->wqh after > removing poll from waitqueue to make sure it won't be freed twice. > > Cc: Darren Kenny <darren.kenny@oracle.com> > Reported-by: syzbot+c0272972b01b872e604a@syzkaller.appspotmail.com > Fixes: 2b8b328b61c79 ("vhost_net: handle polling errors when setting backend") > Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> > --- > Changes from V1: > - tweak the commit log for to match the code > --- > drivers/vhost/vhost.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index 1b3e8d2d..5d5a9d9 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -212,8 +212,7 @@ int vhost_poll_start(struct vhost_poll *poll, struct file *file) > if (mask) > vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask)); > if (mask & EPOLLERR) { > - if (poll->wqh) > - remove_wait_queue(poll->wqh, &poll->wait); > + vhost_poll_stop(poll); > ret = -EINVAL; > } > > -- > 2.7.4
From: Jason Wang <jasowang@redhat.com> Date: Tue, 27 Mar 2018 20:50:52 +0800 > We tried to remove vq poll from wait queue, but do not check whether > or not it was in a list before. This will lead double free. Fixing > this by switching to use vhost_poll_stop() which zeros poll->wqh after > removing poll from waitqueue to make sure it won't be freed twice. > > Cc: Darren Kenny <darren.kenny@oracle.com> > Reported-by: syzbot+c0272972b01b872e604a@syzkaller.appspotmail.com > Fixes: 2b8b328b61c79 ("vhost_net: handle polling errors when setting backend") > Signed-off-by: Jason Wang <jasowang@redhat.com> > --- > Changes from V1: > - tweak the commit log for to match the code Applied and queued up for -stable, thank you.
On Tue, Mar 27, 2018 at 08:50:52PM +0800, Jason Wang wrote: > We tried to remove vq poll from wait queue, but do not check whether > or not it was in a list before. This will lead double free. Fixing > this by switching to use vhost_poll_stop() which zeros poll->wqh after > removing poll from waitqueue to make sure it won't be freed twice. > > Cc: Darren Kenny <darren.kenny@oracle.com> > Reported-by: syzbot+c0272972b01b872e604a@syzkaller.appspotmail.com > Fixes: 2b8b328b61c79 ("vhost_net: handle polling errors when setting backend") > Signed-off-by: Jason Wang <jasowang@redhat.com> OK with this the only bug we have is where get user pages returns 0 (Reported-by: syzbot+6304bf97ef436580fede@syzkaller.appspotmail.com) > --- > Changes from V1: > - tweak the commit log for to match the code > --- > drivers/vhost/vhost.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index 1b3e8d2d..5d5a9d9 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -212,8 +212,7 @@ int vhost_poll_start(struct vhost_poll *poll, struct file *file) > if (mask) > vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask)); > if (mask & EPOLLERR) { > - if (poll->wqh) > - remove_wait_queue(poll->wqh, &poll->wait); > + vhost_poll_stop(poll); > ret = -EINVAL; > } > > -- > 2.7.4
On 2018年03月29日 12:20, Michael S. Tsirkin wrote: > On Tue, Mar 27, 2018 at 08:50:52PM +0800, Jason Wang wrote: >> We tried to remove vq poll from wait queue, but do not check whether >> or not it was in a list before. This will lead double free. Fixing >> this by switching to use vhost_poll_stop() which zeros poll->wqh after >> removing poll from waitqueue to make sure it won't be freed twice. >> >> Cc: Darren Kenny<darren.kenny@oracle.com> >> Reported-by:syzbot+c0272972b01b872e604a@syzkaller.appspotmail.com >> Fixes: 2b8b328b61c79 ("vhost_net: handle polling errors when setting backend") >> Signed-off-by: Jason Wang<jasowang@redhat.com> > OK with this the only bug we have is where get user pages returns 0 > (Reported-by:syzbot+6304bf97ef436580fede@syzkaller.appspotmail.com) > > > Thanks for the reminder. I post a patch to avoid this.
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 1b3e8d2d..5d5a9d9 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -212,8 +212,7 @@ int vhost_poll_start(struct vhost_poll *poll, struct file *file) if (mask) vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask)); if (mask & EPOLLERR) { - if (poll->wqh) - remove_wait_queue(poll->wqh, &poll->wait); + vhost_poll_stop(poll); ret = -EINVAL; }
We tried to remove vq poll from wait queue, but do not check whether or not it was in a list before. This will lead double free. Fixing this by switching to use vhost_poll_stop() which zeros poll->wqh after removing poll from waitqueue to make sure it won't be freed twice. Cc: Darren Kenny <darren.kenny@oracle.com> Reported-by: syzbot+c0272972b01b872e604a@syzkaller.appspotmail.com Fixes: 2b8b328b61c79 ("vhost_net: handle polling errors when setting backend") Signed-off-by: Jason Wang <jasowang@redhat.com> --- Changes from V1: - tweak the commit log for to match the code --- drivers/vhost/vhost.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)