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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
Date: Mon, 25 Mar 2019 21:14:06 +0000	[thread overview]
Message-ID: <20190325211405.GP2217@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAHk-=whJ4M5FegOLvnjUtJ0+pHv4L8UNFt+9jJDhox3Ada8kwA@mail.gmail.com>

On Mon, Mar 25, 2019 at 12:18:02PM -0700, Linus Torvalds wrote:
> COMPLETELY UNTESTED. And no filesystems converted to actually use the
> new rcu_destroy_inode() thing.
> 
> Hmm?

Maybe, but we really need to come up with sane documentation on the
entire drop_inode/evict_inode/destroy_inode/rcu_destroy_inode
group ;-/  And I want to understand the writeback-related issues
in ocfs2 and f2fs - the current kludges in those smell fishy.

>  	if (unlikely(inode_init_always(sb, inode))) {
> -		if (inode->i_sb->s_op->destroy_inode)
> +		if (inode->i_sb->s_op->destroy_inode) {
>  			inode->i_sb->s_op->destroy_inode(inode);
> -		else
> +			if (!inode->i_sb->s_op->rcu_destroy_inode)
> +				return NULL;
> +		}
> +		if (!inode->i_sb->s_op->rcu_destroy_inode ||
> +		    !inode->i_sb->s_op->rcu_destroy_inode(inode))
>  			kmem_cache_free(inode_cachep, inode);

ITYM  i_callback(inode); here, possibly suitably renamed.

  reply	other threads:[~2019-03-25 21:14 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-28 17:40 KASAN: use-after-free Read in path_lookupat syzbot
2019-03-25  0:44 ` syzbot
2019-03-25  1:25   ` Linus Torvalds
2019-03-25  1:23 ` Linus Torvalds
2019-03-25  4:57   ` Al Viro
2019-03-25  9:15     ` Daniel Borkmann
2019-03-25 11:11       ` Al Viro
2019-03-25 11:17         ` Al Viro
2019-03-25 11:21           ` Daniel Borkmann
2019-03-25 18:36     ` Linus Torvalds
2019-03-25 19:18       ` Linus Torvalds
2019-03-25 21:14         ` Al Viro [this message]
2019-03-25 21:45           ` Linus Torvalds
2019-03-25 22:04             ` Daniel Borkmann
2019-03-25 22:13               ` Linus Torvalds
2019-03-25 22:41                 ` Daniel Borkmann
2019-03-25 22:49               ` Al Viro
2019-03-25 23:37             ` Al Viro
2019-03-25 23:44               ` Alexei Starovoitov
2019-03-26  0:21                 ` Al Viro
2019-03-26  1:38               ` ceph: fix use-after-free on symlink traversal Al Viro
2019-03-26  1:39                 ` jffs2: " Al Viro
2019-03-26  1:40                 ` ubifs: " Al Viro
2019-03-26  1:43                 ` debugfs: " Al Viro
2019-03-26 10:41                 ` ceph: " Jeff Layton
2019-03-26 11:38                 ` Ilya Dryomov
2019-03-26  1:45               ` KASAN: use-after-free Read in path_lookupat Al Viro
2019-04-10 18:11                 ` Al Viro
2019-04-10 19:44                   ` Linus Torvalds
2019-03-25 19:43       ` Al Viro
2019-03-25 22:48         ` Dave Chinner
2019-03-25 23:02           ` Al Viro
     [not found]             ` <CAGe7X7mb=gK7zhSwmT_6mmmkcbjhZAOb=wj31BdUcHkNUPsm2Q@mail.gmail.com>
2019-03-26  4:15               ` Al Viro
2019-03-27 16:58                 ` Jan Kara
2019-03-27 18:59                   ` Al Viro
2019-03-28  9:00                     ` Jan Kara
2019-03-27 17:22             ` Jan Kara

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