bug#52049: closed (Bug in shred -u)

[GNU bug Tracking System]

Your message dated Mon, 22 Nov 2021 18:12:47 -0800
with message-id <5e75f1dc-f2fd-abe0-93bb-761017430106@cs.ucla.edu>
and subject line Re: bug#52049: More Information
has caused the debbugs.gnu.org bug report #52049,
regarding Bug in shred -u
to be marked as done.

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52049: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=52049
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--- Begin Message --- Subject: Re: Bug in shred -u Date: Mon, 22 Nov 2021 16:21:37 -0700

Sorry. I thought I was on 20.04 Ubuntu, but reading my report of a bug, I was not.

Please disregard this, as there is no failure on more current OSs.

On Mon, Nov 22, 2021 at 3:20 PM David McLaughlin <david.mclaughlin@theredx.com> wrote:

Hello,

It seems that shred utilizes a pattern of renaming and then unlinking.

However, I don't see the use of a lock for this pattern and so there is a race condition and the shred command can fail. This test case is timing sensitive, and therefore doesn't happen every time. But it happens frequently. I am trying to write robust code that depends on shred and I find this issue is problematic.

Test case:

$ touch a b c && for file in a b c; do shred -u -n 1 $file & done && wait
[1] 28262
[2] 28263
[3] 28264
shred: c: failed to remove: No such file or directory
[1]   Done                    shred -u -n 1 "$file"
[2]-  Done                    shred -u -n 1 "$file"
[3]+  Exit 1                  shred -u -n 1 "$file"

Other information:

$ shred --version
shred (GNU coreutils) 8.21
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Colin Plumb.

$ cat /etc/os-release
NAME="Ubuntu"
VERSION="14.04.6 LTS, Trusty Tahr"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 14.04.6 LTS"
VERSION_ID="14.04"
HOME_URL="http://www.ubuntu.com/"
SUPPORT_URL="http://help.ubuntu.com/"
BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"

$ bash --version
GNU bash, version 4.3.11(1)-release (x86_64-pc-linux-gnu)
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>

This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

--- End Message ---

> --- Begin Message ---
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> Subject: 
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> Re: bug#52049: More Information
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>
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> Date: 
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> Mon, 22 Nov 2021 18:12:47 -0800
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> User-agent: 
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> Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.3.0
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> On 11/22/21 17:21, David McLaughlin wrote:
> > Please disregard this, as there is no failure with shred version 8.30.
>
> Thanks for letting us know; closing the bug report
>
>
> --- End Message ---