Messages in this thread | | | Date | Mon, 31 May 2004 18:08:17 +0200 | From | Herbert Poetzl <> | Subject | Re: file attributes (ext2/3) in 2.4.26 |
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On Mon, May 31, 2004 at 12:05:37PM -0300, Marcelo Tosatti wrote: > On Fri, May 21, 2004 at 12:48:09AM +0200, Herbert Poetzl wrote: > > On Thu, May 20, 2004 at 06:59:09PM -0300, Marcelo Tosatti wrote: > > > On Mon, May 17, 2004 at 08:51:41PM +0200, Herbert Poetzl wrote: > > > > > > > > Hi Folks! > > > > > > > > is it intentional that the file attributes > > > > (those accessible with chattr -*) are modifyable > > > > even if a file has the 'i' immutable flag set, > > > > and the user is lacking CAP_IMMUTABLE (or all > > > > CAPs if you prefer that ;) > > > > > > > > # touch /tmp/x > > > > # chattr +iaA /tmp/x > > > > > > > > # lcap -z > > > > # chattr -i /tmp/x > > > > chattr: Operation not permitted while setting flags on /tmp/x > > > > > > > > # chattr -A /tmp/x > > > > # lsattr /tmp/x > > > > ----ia------- /tmp/x > > > > > > > > I'd consider this a bug, but it might be some > > > > strange posix/linux conformance issue too ... > > > > > > > > let me know if this _is_ a bug, if so, I'm > > > > willing to provide patches to fix it ... > > > > > > Hi Herbert, > > > > > > The chattr man page says > > > > > > A file with the `i' attribute cannot be modified: it cannot be deleted > > > or renamed, no link can be created to this file and no data can be > > > written to the file. Only the superuser or a process possessing the > > > CAP_LINUX_IMMUTABLE capability can set or clear this attribute. > > > > > > You still can modify other flags from the file, right? > > > > yep, that is what I consider unexpected behavior, but the > > man page doesn't say anything about other flags ... > > > > in the example above (which should be easy to verify) the > > 'A' (noatime) flag is cleared while 'i' is set and the > > user (root) has no capability at all ... > > > > the same is true for all other attribute flags for > > ext2/ext3, reiserfs and probably other fs implementing > > those attributes. > > Hi again Herbert, > > I suppose this is expected behaviour, a file with 'i' cannot > be modified, deleted or renamed and no link can be created to this > file and no data written to the file. Its valid to change the file > attributes.
well, if the kernel development, at some point, decides to get rid of the suid stuff, and replace it by something CAP* based, then this will be fun, as it is then possible to modify the attributes of immutable files without CAP_IMMUTABLE ...
> Not sure if any standard covers this, but it does not seem to be > a problem.
okay, I have to handle this in linux-vserver anyway, so I just wanted to know if this was on purpose or accidentially ...
> I suppose v2.6 behaves the same?
yep, it does ...
best, Herbert
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