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From: fjohnber@zoho.com (Fredrick)
To: kernelnewbies@lists.kernelnewbies.org
Subject: Does Linux process exist information leakage?
Date: Tue, 17 Jan 2012 17:53:10 -0800	[thread overview]
Message-ID: <4F162606.4090003@zoho.com> (raw)
In-Reply-To: <CAMjnu2camLaZd3fU4Ar_dD61sgKr79Bo21r89P8Kaj_fLDq3eA@mail.gmail.com>

When you malloc a memory or mmap a MAP_ANON memory, it is virtually 
allocated. When you read or write to it, the process takes a page fault. 
The page fault handler zeroes those memory and hands it to the process. 
So I think there is no leak.

-Fredrick

On 01/11/2012 04:53 AM, ??? wrote:
> Hi,
>     My tutor asked me to test whether one process leaves information in
> memory after it is dead. I tried to search some article about such thing
> on the Internet but there seems to be no one discuss about it. And after
> that, I tried to write some program in the User Mode to test it, using
> fork() to create lots of processes and filling char 'a' into a 102400
> bytes char array in each process. Then I used malloc() to get some
> memory to seek char 'a' in a new one process or many new processes, but
> failed. All memory I malloced was full of zero.
>     As the man page of malloc said:"The memory is not initialized", I
> believe that the memory which was got by malloc() could be used by other
> process, and therefor information leakage exists. But how can I test it?
> Or where can I get related information?
>     Thanks!
>
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

  parent reply	other threads:[~2012-01-18  1:53 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-11 12:53 Does Linux process exist information leakage? 夏业添
2012-01-11 16:23 ` Jonathan Neuschäfer
2012-01-11 16:45 ` Dave Hylands
2012-01-11 17:52   ` Scott Lovenberg
2012-01-12  2:14     ` 夏业添
2012-01-12 17:00     ` Jonathan Neuschäfer
2012-01-16 18:19       ` Scott Lovenberg
2012-01-16 23:45         ` Jonathan Neuschäfer
2012-01-19 14:47           ` Scott Lovenberg
2012-01-16 18:45       ` Greg Freemyer
2012-01-16 20:44         ` Scott Lovenberg
2012-01-12  2:05   ` 夏业添
2012-01-11 18:44 ` Greg Freemyer
2012-01-19 20:23   ` Rik van Riel
     [not found] ` <CAOfVmNFuBCjWb7-5rJaU7ksgcU8LyAW15JiEwa2PigZL3zC0aw@mail.gmail.com>
2012-01-12  2:30   ` 夏业添
2012-01-18  1:53 ` Fredrick [this message]
     [not found]   ` <CAOfVmNFN-GLDwkfLKG11iw7-p6KerDmyoMxV1oSD5WSYJMXc0g@mail.gmail.com>
2012-01-18 11:43     ` beyond.hack
2012-01-19  1:27   ` 夏业添
2012-01-19  7:12     ` SaNtosh kuLkarni
2012-01-19  8:37       ` SaNtosh kuLkarni
2012-01-20  6:52     ` Fredrick
2012-01-19 14:48   ` Scott Lovenberg

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