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Date: Wed, 6 Apr 2016 17:13:38 +0100
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] proc: fix dereference of ERR_PTR
Message-ID: <20160406161338.GA25498@ZenIV.linux.org.uk>
References: <1459937265-4364-1-git-send-email-sudipm.mukherjee@gmail.com>
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On Wed, Apr 06, 2016 at 11:07:45AM +0100, Sudip Mukherjee wrote:
> On the unlikely event of a bad name, d_hash_and_lookup() can return the
> error value in ERR_PTR(). And we were only checking the return value of
> d_hash_and_lookup() to be NULL. In case it is not NULL and has some
> error then d_inode() will try to dereference it later.

s/unlikely/impossible/ - procfs doesn't _have_ ->d_hash.  NAK; at most
add a
        /* no ->d_hash() rejects on procfs */
comment as we have next to another call site in procfs.