From: Al Viro <viro@zeniv.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH 6/6] eventfs: clean up dentry ops and add revalidate function
Date: Wed, 31 Jan 2024 02:46:26 +0000 [thread overview]
Message-ID: <20240131024626.GQ2087318@ZenIV> (raw)
In-Reply-To: <CAHk-=wie3VgLatmR4J_VpnyJR-qKppz=gnDfxEa9Gyy-7cH7HQ@mail.gmail.com>
On Tue, Jan 30, 2024 at 06:37:49PM -0800, Linus Torvalds wrote:
> On Tue, 30 Jan 2024 at 17:12, Al Viro <viro@zeniv.linux.org.uk> wrote:
> >
> > > + *
> > > + * Note that d_revalidate is called potentially under RCU,
> > > + * so it can't take the eventfs mutex etc. It's fine - if
> > > + * we open a file just as it's marked dead, things will
> > > + * still work just fine, and just see the old stale case.
> >
> > Looks like use after free, unless freeing ei is RCU-delayed...
>
> We hold the ref to the ei in the very dentry that is doing d_revalidate().
What's to stop ->d_revalidate() from being called in parallel with
__dentry_kill()?
next prev parent reply other threads:[~2024-01-31 2:46 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-30 19:03 [PATCH 1/6] tracefs: avoid using the ei->dentry pointer unnecessarily Linus Torvalds
2024-01-30 19:03 ` [PATCH 2/6] eventfsfs: initialize the tracefs inode properly Linus Torvalds
2024-01-30 19:48 ` Steven Rostedt
2024-01-30 19:56 ` Steven Rostedt
2024-01-30 19:49 ` Steven Rostedt
2024-01-30 19:03 ` [PATCH 3/6] tracefs: dentry lookup crapectomy Linus Torvalds
2024-01-30 23:26 ` Al Viro
2024-01-30 23:55 ` Steven Rostedt
2024-01-31 0:07 ` Al Viro
2024-01-31 0:23 ` Al Viro
2024-01-31 0:39 ` Linus Torvalds
2024-01-30 19:03 ` [PATCH 4/6] eventfs: remove unused 'd_parent' pointer field Linus Torvalds
2024-01-30 19:03 ` [PATCH 5/6] eventfs: get rid of dentry pointers without refcounts Linus Torvalds
2024-01-30 20:55 ` Steven Rostedt
2024-01-30 21:52 ` Linus Torvalds
2024-01-30 22:56 ` Steven Rostedt
2024-01-30 22:58 ` Linus Torvalds
2024-01-30 23:04 ` Steven Rostedt
2024-01-30 22:56 ` Linus Torvalds
2024-01-30 23:06 ` Linus Torvalds
2024-01-30 23:10 ` Steven Rostedt
2024-01-30 23:25 ` Linus Torvalds
2024-01-31 0:48 ` Al Viro
2024-01-31 5:09 ` Steven Rostedt
2024-01-31 5:25 ` Linus Torvalds
2024-01-31 5:33 ` Steven Rostedt
2024-01-31 5:57 ` Linus Torvalds
2024-01-31 6:20 ` Linus Torvalds
2024-01-31 12:57 ` Steven Rostedt
2024-01-31 13:14 ` Steven Rostedt
2024-01-31 18:08 ` Linus Torvalds
2024-01-31 18:39 ` Steven Rostedt
2024-01-30 19:03 ` [PATCH 6/6] eventfs: clean up dentry ops and add revalidate function Linus Torvalds
2024-01-30 21:25 ` Steven Rostedt
2024-01-30 21:36 ` Linus Torvalds
2024-01-31 1:12 ` Al Viro
2024-01-31 2:37 ` Linus Torvalds
2024-01-31 2:46 ` Al Viro [this message]
2024-01-31 3:39 ` Linus Torvalds
2024-01-31 4:28 ` Al Viro
2024-01-31 18:00 ` Steven Rostedt
2024-01-31 23:07 ` Masami Hiramatsu
2024-01-31 23:23 ` Steven Rostedt
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