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References: <20240204021436.GH2087318@ZenIV> <20240204021739.1157830-1-viro@zeniv.linux.org.uk>
 <20240204021739.1157830-11-viro@zeniv.linux.org.uk> <20240205-gesponnen-mahnmal-ad1aef11676a@brauner>
In-Reply-To: <20240205-gesponnen-mahnmal-ad1aef11676a@brauner>
From: Miklos Szeredi <miklos@szeredi.hu>
Date: Mon, 5 Feb 2024 14:51:53 +0100
Message-ID: <CAJfpegtJtrCTeRCT3w3qCLWsoDopePwUXmL5O9JtJfSJg17LNg@mail.gmail.com>
Subject: Re: [PATCH 11/13] fuse: fix UAF in rcu pathwalks
To: Christian Brauner <brauner@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>, linux-fsdevel@vger.kernel.org, 
	Linus Torvalds <torvalds@linux-foundation.org>, linux-ext4@vger.kernel.org, 
	linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org
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On Mon, 5 Feb 2024 at 13:31, Christian Brauner <brauner@kernel.org> wrote:
>
> On Sun, Feb 04, 2024 at 02:17:37AM +0000, Al Viro wrote:
> > ->permission(), ->get_link() and ->inode_get_acl() might dereference
> > ->s_fs_info (and, in case of ->permission(), ->s_fs_info->fc->user_ns
> > as well) when called from rcu pathwalk.
> >
> > Freeing ->s_fs_info->fc is rcu-delayed; we need to make freeing ->s_fs_info
> > and dropping ->user_ns rcu-delayed too.
> >
> > Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> > ---
>
> Reviewed-by: Christian Brauner <brauner@kernel.org>

Acked-by: Miklos Szeredi <mszeredi@redhat.com>