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authorCornelia Huck <cornelia.huck@de.ibm.com>2012-11-09 14:54:12 +1030
committerRusty Russell <rusty@rustcorp.com.au>2012-11-09 14:54:24 +1030
commit237242bddc99041e15a4ca51b8439657cadaff17 (patch)
treea506fe81ea564d15ed2544d5bb477bc58405603f /drivers/virtio
parentf6a79af8f3701b5a0df431a76adee212616154dc (diff)
downloadvexpress-lsk-237242bddc99041e15a4ca51b8439657cadaff17.tar.gz
virtio: Don't access index after unregister.
Virtio wants to release used indices after the corresponding virtio device has been unregistered. However, virtio does not hold an extra reference, giving up its last reference with device_unregister(), making accessing dev->index afterwards invalid. I actually saw problems when testing my (not-yet-merged) virtio-ccw code: - device_add virtio-net,id=xxx -> creates device virtio<n> with n>0 - device_del xxx -> deletes virtio<n>, but calls ida_simple_remove with an index of 0 - device_add virtio-net,id=xxx -> tries to add virtio0, which is still in use... So let's save the index we want to release before calling device_unregister(). Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Acked-by: Sjur Brændeland <sjur.brandeland@stericsson.com> Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/virtio')
-rw-r--r--drivers/virtio/virtio.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 1e8659ca27e..809b0de59c0 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -225,8 +225,10 @@ EXPORT_SYMBOL_GPL(register_virtio_device);
void unregister_virtio_device(struct virtio_device *dev)
{
+ int index = dev->index; /* save for after device release */
+
device_unregister(&dev->dev);
- ida_simple_remove(&virtio_index_ida, dev->index);
+ ida_simple_remove(&virtio_index_ida, index);
}
EXPORT_SYMBOL_GPL(unregister_virtio_device);