diff options
| author | Juergen Gross <jgross@suse.com> | 2017-05-18 17:28:48 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-05 14:40:20 +0200 |
| commit | afaee3ef513650b2f6cb9e2c860b9210875a8135 (patch) | |
| tree | 747025cd98a92ffa4008ab882645e67675fab49e /drivers/block | |
| parent | 13fa36f9fbc84c47cef6673d5e2f3a20693d6eff (diff) | |
xen/blkback: don't free be structure too early
commit 71df1d7ccad1c36f7321d6b3b48f2ea42681c363 upstream.
The be structure must not be freed when freeing the blkif structure
isn't done. Otherwise a use-after-free of be when unmapping the ring
used for communicating with the frontend will occur in case of a
late call of xenblk_disconnect() (e.g. due to an I/O still active
when trying to disconnect).
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Steven Haigh <netwiz@crc.id.au>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/xen-blkback/xenbus.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index d8fc9c58e2a3..5dfe6e8af140 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -315,8 +315,10 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif) static void xen_blkif_free(struct xen_blkif *blkif) { - xen_blkif_disconnect(blkif); + WARN_ON(xen_blkif_disconnect(blkif)); xen_vbd_free(&blkif->vbd); + kfree(blkif->be->mode); + kfree(blkif->be); /* Make sure everything is drained before shutting down */ kmem_cache_free(xen_blkif_cachep, blkif); @@ -511,8 +513,6 @@ static int xen_blkbk_remove(struct xenbus_device *dev) /* Put the reference we set in xen_blkif_alloc(). */ xen_blkif_put(be->blkif); - kfree(be->mode); - kfree(be); return 0; } |