On Tue, Dec 04, 2012 at 12:11:48AM +0300, Dan Carpenter wrote: > Hello Roger Pau Monne, > > The patch 4d4f270f1880: "xen-blkback: move free persistent grants > code" from Nov 16, 2012, leads to the following warning: > drivers/block/xen-blkback/blkback.c:238 free_persistent_gnts() > warn: 'persistent_gnt' was already freed. > > drivers/block/xen-blkback/blkback.c > 232 pages[segs_to_unmap] = persistent_gnt->page; > 233 rb_erase(&persistent_gnt->node, root); > 234 kfree(persistent_gnt); > ^^^^^^^^^^^^^^^^^^^^ > kfree(); >
Also persistent_gnt is the list iterator inside a foreach_grant() loop. It needs a _safe() version like list_for_each_safe() where it saves the next entry in the list at the start so we don't dereference a freed entry. regards, dan carpenter _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
