linux-kernel - Re: fs/attr.c patch

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Message-ID: <20110519145004.GA15698@mail.hallyn.com>
Date:	Thu, 19 May 2011 09:50:04 -0500
From:	"Serge E. Hallyn" <serge@...lyn.com>
To:	samsonov@...sta.ru
Cc:	linux-kernel@...r.kernel.org
Subject: Re: fs/attr.c patch

But you're removing the ability for a process with CAP_CHOWN to
chgrp all files.

You also change behavior (which may be wrong) when doing chgrp to
which would cause no change but the group is not in_group_p(),
which might break current users.

Quoting samsonov@...sta.ru (samsonov@...sta.ru):
> --- ./linux-2.6.33.4.orig/fs/attr.c	2010-05-13 02:04:27.000000000 +0400
> +++ ./linux-2.6.33.4/fs/attr.c	2011-05-19 15:43:14.533672804 +0400
> @@ -35,9 +35,7 @@
>  
>  	/* Make sure caller can chgrp. */
>  	if ((ia_valid & ATTR_GID) &&
> -	    (current_fsuid() != inode->i_uid ||
> -	    (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) &&
> -	    !capable(CAP_CHOWN))
> +	    !(in_group_p(attr->ia_gid) && is_owner_or_cap(inode)))
>  		goto error;
>  
>  	/* Make sure a caller can chmod. */
> 
> I think that fileowner can change group of file.
> 
> 
>  
> 
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