On Mon, Mar 05, 2012 at 06:18:23PM +0100, Miklos Szeredi wrote: > Andy Whitcroft <apw@xxxxxxxxxxxxx> writes: > > > When checking permissions on an overlayfs inode we do not take into > > account either device cgroup restrictions nor security permissions. > > This allows a user to mount an overlayfs layer over a restricted device > > directory and by pass those permissions to open otherwise restricted > > files. > > > > Use devcgroup_inode_permission() and security_inode_permission() against > > the underlying inodes when calculating ovl_permission(). > > Andy, > > Thanks for the patch. > > __devcgroup_inode_permission() and security_inode_permission() are not > exported to modules, so this will not work if overlayfs is a module. > > We could export those but I think a better solution is to split out the > part of inode_permission() that doesn't check for a read-only fs and > export that. Yeah that makes much more sense. I got caught out by some exports required for aufs3 which was also applied in my test environment. How about the following pair of patches? -apw -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
