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Commit 71df1d7c authored by Juergen Gross's avatar Juergen Gross Committed by Konrad Rzeszutek Wilk
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xen/blkback: don't free be structure too early 



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: default avatarJuergen Gross <jgross@suse.com>
Tested-by: default avatarSteven Haigh <netwiz@crc.id.au>
Acked-by: default avatarRoger Pau Monné <roger.pau@citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 46464411

drivers/block/xen-blkback/xenbus.c

+3 −4
Original line number Diff line number Diff line
@@ -315,9 +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);
@@ -514,8 +515,6 @@ static int xen_blkbk_remove(struct xenbus_device *dev) 
		xen_blkif_put(be->blkif);

	}



	kfree(be->mode);

	kfree(be);

	return 0;

}