On Wed, Aug 26, 2020 at 11:07 AM Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote:
>
> Change the data used in UDS SO_PEERSEC processing from a
> secid to a more general struct lsmblob. Update the
> security_socket_getpeersec_dgram() interface to use the
> lsmblob. There is a small amount of scaffolding code
> that will come out when the security_secid_to_secctx()
> code is brought in line with the lsmblob.
>
> Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
> ---
> include/linux/security.h | 7 +++++--
> include/net/af_unix.h | 2 +-
> include/net/scm.h | 8 +++++---
> net/ipv4/ip_sockglue.c | 8 +++++---
> net/unix/af_unix.c | 6 +++---
> security/security.c | 18 +++++++++++++++---
> 6 files changed, 34 insertions(+), 15 deletions(-)
...
> diff --git a/include/net/af_unix.h b/include/net/af_unix.h
> index f42fdddecd41..a86da0cb5ec1 100644
> --- a/include/net/af_unix.h
> +++ b/include/net/af_unix.h
> @@ -36,7 +36,7 @@ struct unix_skb_parms {
> kgid_t gid;
> struct scm_fp_list *fp; /* Passed files */
> #ifdef CONFIG_SECURITY_NETWORK
> - u32 secid; /* Security ID */
> + struct lsmblob lsmblob; /* Security LSM data */
As mentioned in a previous revision, I remain concerned that this is
going to become a problem due to the size limit on unix_skb_parms. I
would need to redo the math to be certain, but if I recall correctly
this would limit us to five LSMs assuming both that we don't need to
grow the per-LSM size of lsmblob *and* the netdev folks don't decide
to add more fields to the unix_skb_parms.
I lost track of that earlier discussion so I'm not sure where it ended
up, but if there is a viable alternative it might be a good idea to
pursue it.
--
paul moore
www.paul-moore.com
