From: Waiman Long <waiman.long@hp.com>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
"Chandramouleeswaran, Aswin" <aswin@hp.com>,
"Norton, Scott J" <scott.norton@hp.com>
Subject: Re: [PATCH] dcache: Translating dentry into pathname without taking rename_lock
Date: Wed, 04 Sep 2013 21:55:43 -0400 [thread overview]
Message-ID: <5227E49F.1090809@hp.com> (raw)
In-Reply-To: <20130904194341.GL13318@ZenIV.linux.org.uk>
On 09/04/2013 03:43 PM, Al Viro wrote:
> On Wed, Sep 04, 2013 at 03:33:00PM -0400, Waiman Long wrote:
>
>> I have thought about that. But if a d_move() is going on, the string
>> in the buffer will be discarded as the sequence number will change.
>> So whether or not it have embedded null byte shouldn't matter. That
>> is why I didn't add code to do byte-by-byte copy at this first
>> patch. I can add code to do that if you think it is safer to do so.
> Sigh... Junk in the output is not an issue; reading from invalid address
> is, since you might not survive to the sequence number check. Again,
> if p is an address returned by kmalloc(size, ...), dereferencing p + offset
> is not safe unless offset is less than size.
Yeah, I understand that. As said in my reply to Linus, I will use
memchr() to see if there is null byte within the specified length. If
one is found, I will assume the string is not valid and return error to
the caller.
Longman
next prev parent reply other threads:[~2013-09-05 1:55 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-04 19:05 [PATCH] dcache: Translating dentry into pathname without taking rename_lock Waiman Long
2013-09-04 19:11 ` Al Viro
2013-09-04 19:33 ` Waiman Long
2013-09-04 19:43 ` Al Viro
2013-09-05 1:55 ` Waiman Long [this message]
2013-09-05 2:42 ` Al Viro
[not found] ` <CA+55aFwW+hWwQd8+NgukSidHbf2bnd6QO0yKK9NAgX+9rt0cOQ@mail.gmail.com>
[not found] ` <5227E321.4090008@hp.com>
2013-09-05 2:48 ` Linus Torvalds
2013-09-05 4:20 ` Al Viro
2013-09-04 19:26 ` Waiman Long
2013-09-04 20:40 ` John Stoffel
2013-09-05 2:04 ` Waiman Long
2013-09-05 13:29 ` John Stoffel
2013-09-05 17:28 ` Waiman Long
2013-09-04 21:31 ` Linus Torvalds
2013-09-05 2:17 ` Waiman Long
-- strict thread matches above, loose matches on Subject: below --
2013-09-05 4:30 George Spelvin
2013-09-05 17:06 ` Waiman Long
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