On Mon, Jan 25, 2021 at 11:03:16AM -0600, Serge Hallyn wrote: > On Mon, Jan 25, 2021 at 05:44:04PM +0100, Christian Brauner wrote: > > On Mon, Jan 25, 2021 at 10:39:01AM -0600, Eric W. Biederman wrote: > > > Christian Brauner <christian.brauner@xxxxxxxxxx> writes: > > > > > > > When executing a setuid binary the kernel will verify in bprm_fill_uid() > > > > that the inode has a mapping in the caller's user namespace before > > > > setting the callers uid and gid. Let bprm_fill_uid() handle idmapped > > > > mounts. If the inode is accessed through an idmapped mount it is mapped > > > > according to the mount's user namespace. Afterwards the checks are > > > > identical to non-idmapped mounts. If the initial user namespace is > > > > passed nothing changes so non-idmapped mounts will see identical > > > > behavior as before. > > > > > > This does not handle the v3 capabilites xattr with embeds a uid. > > > So at least at that level you are missing some critical conversions. > > > > Thanks for looking. Vfs v3 caps are handled earlier in the series. I'm > > not sure what you're referring to here. There are tests in xfstests that > > verify vfs3 capability behavior. > > *just* to make sure i'm not misunderstanding - s/vfs3/v3/ right? Yes, in my mind it's always as "vfs v3 caps -> vfs3 caps". Sorry for the confusion.
