GNU bug report logs - #45886
mkdir -m argument does not work correctly, applies incorrect permissions

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Davin McCall <davmac <at> davmac.org>
To: bug-coreutils <at> gnu.org
Subject: mkdir -m argument does not work correctly, applies incorrect
 permissions
Date: Fri, 15 Jan 2021 17:45:29 +1000

[Message part 1 (text/plain, inline)]

Coreutils 8.32 (and possibly earlier) "mkdir -m <mode> ..." appears to
ignore parts of the mode specification. POSIX suggests that with -m
specified, the mode is "relative" to a=rwx. That implies a mode of "o-w"
should yield a mode of "rwxrwxr-x", and a mode of "o+w" should yield
"rwxrwxrwx". Instead:

$ mkdir -m o-w t1
$ mkdir -m o+w t2
$ ls -l
total 8
drwxr-xr-x 2 davmac users 4096 Jan 15 17:27 t1
drwxrwxrwx 2 davmac users 4096 Jan 15 17:27 t2
$

So, the "o+w" or "o-w" selects the "other" permissions but also the
"group" permissions. This also happens with "g+w" and "g-w" (i.e. both
"group" and "other" permissions get set or cleared). This implies it's
not just a case of the initial mode not matching POSIX, but somehow "o"
and "g" are being applied incorrectly.

Setting POSIXLY_CORRECT makes no difference.

[Message part 2 (text/html, inline)]

Message #10 received at 45886-done <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Davin McCall <davmac <at> davmac.org>
Cc: 14371 <at> debbugs.gnu.org, 45886-done <at> debbugs.gnu.org
Subject: Re: bug#45886: mkdir -m argument does not work correctly, applies
 incorrect permissions
Date: Fri, 15 Jan 2021 03:03:03 -0800

[Message part 1 (text/plain, inline)]

Thanks for the bug report. I reproduced the problem and installed the 
attached patch to fix it.

[0001-mkdir-fix-bug-when-m-s-more-generous-than-umask.patch (text/x-patch, attachment)]

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