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Date:   Fri, 4 Oct 2019 15:27:48 +0100
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     Christian Brauner <christian.brauner@ubuntu.com>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        linux-kernel@vger.kernel.org, Will Deacon <will@kernel.org>,
        Kate Stewart <kstewart@linuxfoundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Amir Goldstein <amir73il@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Varad Gautam <vrd@amazon.de>, stable@vger.kernel.org,
        Jan Glauber <jglauber@marvell.com>
Subject: Re: [PATCH] devpts: Fix NULL pointer dereference in dcache_readdir()
Message-ID: <20191004142748.GG26530@ZenIV.linux.org.uk>
References: <20191004140503.9817-1-christian.brauner@ubuntu.com>
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On Fri, Oct 04, 2019 at 04:05:03PM +0200, Christian Brauner wrote:
> From: Will Deacon <will@kernel.org>
> 
> Closing /dev/pts/ptmx removes the corresponding pty under /dev/pts/
> without synchronizing against concurrent path walkers. This can lead to
> 'dcache_readdir()' tripping over a 'struct dentry' with a NULL 'd_inode'
> field:

FWIW, vfs.git#fixes (or #next.dcache) ought to deal with that one.