similar to: Forward stepwise procedure w/ stepAIC

When a file system is mounted on a virtio-blk disk, we then remove it and then reattach it, the reattached disk gets the same disk name and ids as the hot removed one. This leads to very nasty effects - mostly rendering the newly attached device completely unusable. Trying what happens when I do the same thing with a USB device, I saw that the sd node simply doesn't get free'd when a

When a file system is mounted on a virtio-blk disk, we then remove it and then reattach it, the reattached disk gets the same disk name and ids as the hot removed one. This leads to very nasty effects - mostly rendering the newly attached device completely unusable. Trying what happens when I do the same thing with a USB device, I saw that the sd node simply doesn't get free'd when a

A userspace process holding a file descriptor to a virtio_blk device can still invoke block_device_operations after hot unplug. For example, a program that has /dev/vdb open can call ioctl(HDIO_GETGEO) after hot unplug to invoke virtblk_getgeo(). Introduce a reference count in struct virtio_blk so that its lifetime covers both virtio_driver probe/remove and block_device_operations open/release

A userspace process holding a file descriptor to a virtio_blk device can still invoke block_device_operations after hot unplug. For example, a program that has /dev/vdb open can call ioctl(HDIO_GETGEO) after hot unplug to invoke virtblk_getgeo(). Introduce a reference count in struct virtio_blk so that its lifetime covers both virtio_driver probe/remove and block_device_operations open/release

A userspace process holding a file descriptor to a virtio_blk device can still invoke block_device_operations after hot unplug. This leads to a use-after-free accessing vblk->vdev in virtblk_getgeo() when ioctl(HDIO_GETGEO) is invoked: BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 IP: [<ffffffffc00e5450>] virtio_check_driver_offered_feature+0x10/0x90

A userspace process holding a file descriptor to a virtio_blk device can still invoke block_device_operations after hot unplug. This leads to a use-after-free accessing vblk->vdev in virtblk_getgeo() when ioctl(HDIO_GETGEO) is invoked: BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 IP: [<ffffffffc00e5450>] virtio_check_driver_offered_feature+0x10/0x90

On Sun, 5 Oct 2014 19:07:07 +0300 "Michael S. Tsirkin" <mst at redhat.com> wrote: > Now that virtio core ensures config changes don't > arrive during probing, drop config_enable flag > in virtio blk. > On removal, flush is now sufficient to guarantee that > no change work is queued. > > This help simplify the driver, and will allow > setting DRIVER_OK

On Sun, 5 Oct 2014 19:07:07 +0300 "Michael S. Tsirkin" <mst at redhat.com> wrote: > Now that virtio core ensures config changes don't > arrive during probing, drop config_enable flag > in virtio blk. > On removal, flush is now sufficient to guarantee that > no change work is queued. > > This help simplify the driver, and will allow > setting DRIVER_OK

On Tue, Apr 28, 2020 at 03:30:09PM +0100, Stefan Hajnoczi wrote: > A userspace process holding a file descriptor to a virtio_blk device can > still invoke block_device_operations after hot unplug. For example, a > program that has /dev/vdb open can call ioctl(HDIO_GETGEO) after hot > unplug to invoke virtblk_getgeo(). which causes what? a use after free? > > Introduce a

On Mon, 6 Oct 2014 15:09:53 +0300 "Michael S. Tsirkin" <mst at redhat.com> wrote: > On Mon, Oct 06, 2014 at 01:42:29PM +0200, Cornelia Huck wrote: > > On Sun, 5 Oct 2014 19:07:07 +0300 > > "Michael S. Tsirkin" <mst at redhat.com> wrote: > > > > > Now that virtio core ensures config changes don't > > > arrive during

On Mon, 6 Oct 2014 15:09:53 +0300 "Michael S. Tsirkin" <mst at redhat.com> wrote: > On Mon, Oct 06, 2014 at 01:42:29PM +0200, Cornelia Huck wrote: > > On Sun, 5 Oct 2014 19:07:07 +0300 > > "Michael S. Tsirkin" <mst at redhat.com> wrote: > > > > > Now that virtio core ensures config changes don't > > > arrive during

On Wed, Apr 29, 2020 at 05:53:45PM +0100, Stefan Hajnoczi wrote: > A userspace process holding a file descriptor to a virtio_blk device can > still invoke block_device_operations after hot unplug. This leads to a > use-after-free accessing vblk->vdev in virtblk_getgeo() when > ioctl(HDIO_GETGEO) is invoked: > > BUG: unable to handle kernel NULL pointer dereference at

From: Stefan Hajnoczi <stefanha at redhat.com> [ Upstream commit 90b5feb8c4bebc76c27fcaf3e1a0e5ca2d319e9e ] A userspace process holding a file descriptor to a virtio_blk device can still invoke block_device_operations after hot unplug. This leads to a use-after-free accessing vblk->vdev in virtblk_getgeo() when ioctl(HDIO_GETGEO) is invoked: BUG: unable to handle kernel NULL pointer

From: Stefan Hajnoczi <stefanha at redhat.com> [ Upstream commit 90b5feb8c4bebc76c27fcaf3e1a0e5ca2d319e9e ] A userspace process holding a file descriptor to a virtio_blk device can still invoke block_device_operations after hot unplug. This leads to a use-after-free accessing vblk->vdev in virtblk_getgeo() when ioctl(HDIO_GETGEO) is invoked: BUG: unable to handle kernel NULL pointer

From: Stefan Hajnoczi <stefanha at redhat.com> [ Upstream commit 90b5feb8c4bebc76c27fcaf3e1a0e5ca2d319e9e ] A userspace process holding a file descriptor to a virtio_blk device can still invoke block_device_operations after hot unplug. This leads to a use-after-free accessing vblk->vdev in virtblk_getgeo() when ioctl(HDIO_GETGEO) is invoked: BUG: unable to handle kernel NULL pointer

From: Stefan Hajnoczi <stefanha at redhat.com> [ Upstream commit 90b5feb8c4bebc76c27fcaf3e1a0e5ca2d319e9e ] A userspace process holding a file descriptor to a virtio_blk device can still invoke block_device_operations after hot unplug. This leads to a use-after-free accessing vblk->vdev in virtblk_getgeo() when ioctl(HDIO_GETGEO) is invoked: BUG: unable to handle kernel NULL pointer

A userspace process holding a file descriptor to a virtio_blk device can still invoke block_device_operations after hot unplug. This leads to a use-after-free accessing vblk->vdev in virtblk_getgeo() when ioctl(HDIO_GETGEO) is invoked: BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 IP: [<ffffffffc00e5450>] virtio_check_driver_offered_feature+0x10/0x90

A userspace process holding a file descriptor to a virtio_blk device can still invoke block_device_operations after hot unplug. This leads to a use-after-free accessing vblk->vdev in virtblk_getgeo() when ioctl(HDIO_GETGEO) is invoked: BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 IP: [<ffffffffc00e5450>] virtio_check_driver_offered_feature+0x10/0x90

Now that virtio core ensures config changes don't arrive during probing, drop config_enable flag in virtio blk. On removal, flush is now sufficient to guarantee that no change work is queued. This help simplify the driver, and will allow setting DRIVER_OK earlier without losing config change notifications. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> ---

Now that virtio core ensures config changes don't arrive during probing, drop config_enable flag in virtio blk. On removal, flush is now sufficient to guarantee that no change work is queued. This help simplify the driver, and will allow setting DRIVER_OK earlier without losing config change notifications. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> ---