From: Al Viro <viro@zeniv.linux.org.uk>
To: Kees Cook <keescook@chromium.org>
Cc: James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] securityfs: Add missing d_delete() call on removal
Date: Wed, 6 May 2020 19:49:20 +0100 [thread overview]
Message-ID: <20200506184920.GD23230@ZenIV.linux.org.uk> (raw)
In-Reply-To: <202005060831.C05759E@keescook>
On Wed, May 06, 2020 at 08:34:29AM -0700, Kees Cook wrote:
> Just posted the whole series:
> https://lore.kernel.org/lkml/20200506152114.50375-1-keescook@chromium.org/
>
> But the specific question was driven by this patch:
> https://lore.kernel.org/lkml/20200506152114.50375-11-keescook@chromium.org/
Yecchh... First of all, you are leaving a dangling pointer in your
struct pstore_private ->dentry. What's more, in your case d_delete()
is definitely wrong - either there are other references to dentry
(in which case d_delete() is the same as d_drop()), or dput() right
after it will drive ->d_count to zero and since you end up using
simple_dentry_operations, dentry will be freed immediately after
that.
I have not looked at the locking in that series yet, so no comments
on the races, but in any case - that d_delete() is a misspelled d_drop().
next prev parent reply other threads:[~2020-05-06 18:49 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 23:40 [PATCH] securityfs: Add missing d_delete() call on removal Kees Cook
2020-05-06 1:14 ` Al Viro
2020-05-06 3:28 ` Kees Cook
2020-05-06 4:02 ` Al Viro
2020-05-06 15:34 ` Kees Cook
2020-05-06 18:49 ` Al Viro [this message]
2020-05-06 22:49 ` Kees Cook
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