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Date:   Tue, 26 Mar 2019 01:45:53 +0000
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     syzbot <syzbot+7a8ba368b47fdefca61e@syzkaller.appspotmail.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
        syzkaller-bugs <syzkaller-bugs@googlegroups.com>
Subject: Re: KASAN: use-after-free Read in path_lookupat
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On Mon, Mar 25, 2019 at 11:37:32PM +0000, Al Viro wrote:

> For debugfs it's clearly "use default ->evict_inode(), have explicit
> ->destroy_inode() using free_inode_nonrcu()" - there we have nothing
> else done in ->evict_inode() and kfree is obviously safe in softirq.
> I'll post that (or push to vfs.git#fixes), along with minimal fixes
> for other 3.  If bpf_any_put() is softirq-safe, we'll have the full
> set for -stable and the rest could be done on top of that.
> 
> Won't solve the documetation problem, unfortunately ;-/

Posted; all of those (as well as Daniel's bpf patch) are Cc:stable
fodder.  Documentation is still, er, deficient...