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From: Valdis.Kletnieks@vt.edu
To: Matti Linnanvuori <mattilinnanvuori@yahoo.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: /dev/urandom uses uninit bytes, leaks user data
Date: Sat, 15 Dec 2007 02:54:01 -0500	[thread overview]
Message-ID: <28540.1197705241@turing-police.cc.vt.edu> (raw)
In-Reply-To: Your message of "Fri, 14 Dec 2007 23:20:30 PST." <977119.41267.qm@web52005.mail.re2.yahoo.com>

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On Fri, 14 Dec 2007 23:20:30 PST, Matti Linnanvuori said:
> From: Matti Linnanvuori <mattilinnnvuori@yahoo.com>
> 
> /dev/urandom use no uninit bytes, leak no user data
> 
> Signed-off-by: Matti Linnanvuori <mattilinnnvuori@yahoo.com>
> 
> ---
> 
> --- a/drivers/char/random.c	2007-12-15 09:09:37.895414000 +0200
> +++ b/drivers/char/random.c	2007-12-15 09:12:02.607831500 +0200
> @@ -689,7 +689,7 @@ static ssize_t extract_entropy(struct en
>   */
>  static void xfer_secondary_pool(struct entropy_store *r, size_t nbytes)
>  {
> -	__u32 tmp[OUTPUT_POOL_WORDS];
> +	static __u32 tmp[OUTPUT_POOL_WORDS];

This looks like a race waiting to happen - what lock is held so we don't have
'tmp' smashed by 2 instances on different CPUs (not a problem when each
instance lives on a hopefully separate stack)?

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  reply	other threads:[~2007-12-15  7:54 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-12-15  7:20 Matti Linnanvuori
2007-12-15  7:54 ` Valdis.Kletnieks [this message]
  -- strict thread matches above, loose matches on Subject: below --
2007-12-15 22:44 linux
2007-12-14 19:34 John Reiser
2007-12-14 20:13 ` Matt Mackall
2007-12-14 20:45   ` John Reiser
2007-12-14 23:23     ` Theodore Tso
2007-12-15  0:30       ` John Reiser
2007-12-15  4:32         ` Theodore Tso
2007-12-17 16:30           ` John Reiser
2007-12-17 17:36             ` Theodore Tso
2007-12-18  0:52               ` Andy Lutomirski
2007-12-18  3:05                 ` Theodore Tso
2007-12-18  3:13                   ` David Newall
2007-12-18  3:46                     ` Theodore Tso
2007-12-18  4:09                       ` David Newall
2007-12-18  4:23                         ` Theodore Tso
2007-12-19 22:43                           ` Bill Davidsen
2007-12-19 22:40                         ` Bill Davidsen
2007-12-20  4:18                       ` Andrew Lutomirski
2007-12-20 20:17                         ` Phillip Susi
2007-12-21 16:10                           ` Andrew Lutomirski
2007-12-22  1:14                             ` Theodore Tso
2007-12-26 18:30                             ` Phillip Susi
2007-12-20 20:36                         ` Theodore Tso
2007-12-27 10:44                           ` Pavel Machek
2007-12-18  5:12                 ` David Schwartz
2007-12-17 20:59             ` David Schwartz
2007-12-15  7:13         ` Herbert Xu
2007-12-15 16:30           ` Matt Mackall

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