Re: [PATCH net v3 0/2] security: fixups for the security hooks in sctp

[Richard Haines]

On Sat, 2022-02-12 at 18:59 +0100, Ondrej Mosnacek wrote:
> This is a third round of patches to fix the SCTP-SELinux interaction
> w.r.t. client-side peeloff. The patches are a modified version of Xin
> Long's patches posted previously, of which only a part was merged
> (the
> rest was merged for a while, but was later reverted):
> https://lore.kernel.org/selinux/cover.1635854268.git.lucien.xin@xxxxxxxxx/T/
> 
> In gist, these patches replace the call to
> security_inet_conn_established() in SCTP with a new hook
> security_sctp_assoc_established() and implement the new hook in
> SELinux
> so that the client-side association labels are set correctly (which
> matters in case the association eventually gets peeled off into a
> separate socket).
> 
> Note that other LSMs than SELinux don't implement the SCTP hooks nor
> inet_conn_established, so they shouldn't be affected by any of these
> changes.
> 
> These patches were tested by selinux-testsuite [1] with an additional
> patch [2] and by lksctp-tools func_tests [3].
> 
> Changes since v2:
> - patches 1 and 2 dropped as they are already in mainline (not
> reverted)
> - in patch 3, the return value of security_sctp_assoc_established()
> is
>   changed to int, the call is moved earlier in the function, and if
> the
>   hook returns an error value, the packet will now be discarded,
>   aborting the association
> - patch 4 has been changed a lot - please see the patch description
> for
>   details on how the hook is now implemented and why
> 
> [1] https://github.com/SELinuxProject/selinux-testsuite/
> [2]
> https://patchwork.kernel.org/project/selinux/patch/20211021144543.740762-1-omosnace@xxxxxxxxxx/
> [3] https://github.com/sctp/lksctp-tools/tree/master/src/func_tests
> 
> Ondrej Mosnacek (2):
>   security: add sctp_assoc_established hook
>   security: implement sctp_assoc_established hook in selinux
> 
>  Documentation/security/SCTP.rst | 22 ++++----
>  include/linux/lsm_hook_defs.h   |  2 +
>  include/linux/lsm_hooks.h       |  5 ++
>  include/linux/security.h        |  8 +++
>  net/sctp/sm_statefuns.c         |  8 +--
>  security/security.c             |  7 +++
>  security/selinux/hooks.c        | 90 ++++++++++++++++++++++++-------
> --
>  7 files changed, 103 insertions(+), 39 deletions(-)
> 

Built this patchset on kernel 5.17-rc4 with no problems.
Tested using [PATCH testsuite v3] tests/sctp: add client peeloff tests

Tested-by: Richard Haines <richard_c_haines@xxxxxxxxxxxxxx>