[0/4] seccomp: continue syscall from notifier

Message

Christian Brauner Sept. 18, 2019, 8:48 a.m. UTC

Hey everyone,

This is the patchset coming out of the KSummit session Kees and I gave
in Lisbon last week (cf. [3] which also contains slides with more
details on related things such as deep argument inspection).
The simple idea is to extend the seccomp notifier to allow for the
continuation of a syscall. The rationale for this can be found in the
commit message to [1]. For the curious there is more detail in [2].
This patchset would unblock supervising an extended set of syscalls such
as mount() where a privileged process is supervising the syscalls of a
lesser privileged process and emulates the syscall for the latter in
userspace.
For more comments on security see [1].

Thanks!
Christian

/* References */
[1]: [PATCH 1/4] seccomp: add SECCOMP_RET_USER_NOTIF_ALLOW
[2]: https://lore.kernel.org/r/[e-mail]
[3]: https://linuxplumbersconf.org/event/4/contributions/560

Christian Brauner (4):
  seccomp: add SECCOMP_RET_USER_NOTIF_ALLOW
  seccomp: add two missing ptrace ifdefines
  seccomp: avoid overflow in implicit constant conversion
  seccomp: test SECCOMP_RET_USER_NOTIF_ALLOW

 include/uapi/linux/seccomp.h                  |   2 +
 kernel/seccomp.c                              |  24 +++-
 tools/testing/selftests/seccomp/seccomp_bpf.c | 110 +++++++++++++++++-
 3 files changed, 131 insertions(+), 5 deletions(-)