Messages in this thread | | | Date | Tue, 12 Jul 2016 01:46:23 +0100 | From | Al Viro <> | Subject | Re: [PATCH] vfs: check i_count under lock in evict_inodes |
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On Mon, Jul 11, 2016 at 05:15:04PM -0700, Chunwei Chen wrote: > We need to check i_count again with i_lock held, because iput might re-add > i_count when lazytime is on. Without this check, we could end up with > double-free or use-after-free.
Details, please. Ideally - with a reproducer. Who is calling that iput() at that point of generic_shutdown_super() (has to be another thread) and just what will happen if the same iput() is delayed until *after* evict_inodes(), all the way into ->put_super(). At which point there's no promise whatsoever that the data structures used by ->evict_inode() hadn't been already freed...
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