[PATCH 0/4] seccomp: continue syscall from notifier

Christian Brauner
2019-09-18T08:49:08Z

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/20190719093538.dhyopljyr5ns33qx@brauner.io
[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(-)

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2.23.0