Re: [PATCH 4/6] ext2: tighten restrictions on inode flags

[Andreas Dilger]

On Jun 11, 2008  01:04 +0100, Duane Griffin wrote:
> At the moment there are few restrictions on which flags may be set on which
> inodes. Specifically DIRSYNC may only be set on directories and IMMUTABLE
> and APPEND may not be set on links. Tighten that to disallow TOPDIR being
> set on non-directories and SECRM, UNRM, COMPR, SYNC, DIRTY, COMPRBLK,
> NOCOMP, ECOMPR, INDEX, JOURNAL_DATA and NOTAIL being set on anything but
> regular files or directories.
> 
> Introduce a flags masking function which masks flags based on mode and use
> it during inode creation and when flags are set via the ioctl to facilitate
> future consistency.

This second set of patches is missing out on the presence of the
"EXT2_FL_USER_MODIFIABLE" mask in ext2_ioctl(EXT2_IOC_SETFLAGS).  This is
what prevents "unsettable" flags from being set from userspace.

I don't have any objection to additional filtering to avoid setting the
USER_MODIFIABLE flags on special files.

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/