Re: [PATCH] Fix user.* xattr permission check for sticky dirs

[Timothy Shimmin]

Hi Andreas,

--On 2 November 2006 10:51:21 PM +0100 Andreas Gruenbacher <agruen@xxxxxxx> wrote:

> On Thursday 02 November 2006 20:27, Andrew Morton wrote:
> > On Thu, 2 Nov 2006 17:24:02 +0100
> >
> > Andreas Gruenbacher <agruen@xxxxxxx> wrote:
> > > The user.* extended attributes are only allowed on regular files and
> > > directories. Sticky directories further restrict write access to the
> > > owner and privileged users. (See the attr(5) man page for an
> > > explanation.)
> > >
> > > The original check in ext2/ext3 when user.* xattrs were merged was more
> > > restrictive than intended, and when the xattr permission checks were
> > > moved into the VFS, read access to user.* attributes on sticky directores
> > > ended up being denied in addition.
> >
> > Am struggling to understand the impact of this.  I assume this problem was
> > introduced on Jan 9 by e0ad7b073eb7317e5afe0385b02dcb1d52a1eedf "move xattr
> > permission checks into the VFS"?
>
> Commits e0ad7b073eb7317e5afe0385b02dcb1d52a1eedf and
> c37ef806a3e1c0bca65fd03b7590d56d19625da4 move the following check from
> ext3_xattr_user_set() to xattr_permission(), which is used in vfs_getxattr()
> as well as xfs_setxattr() and vfs_removexattr(),

> so this added the check to
> the xfs_getxattr() path by accident:
>
> []	if (!S_ISREG(inode->i_mode) &&
> []	    (!S_ISDIR(inode->i_mode) || inode->i_mode & S_ISVTX))
> []		return -EPERM;
Now, I'm a bit confused.
xfs_getxattr?
I see the "correct" version of the test in xfs_attr.c/attr_user_capable().

--Tim
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