Message-ID: <20250307213651.3065714-1-bboscaccy@linux.microsoft.com>
Date: Fri,  7 Mar 2025 13:36:37 -0800
From: Blaise Boscaccy <bboscaccy@...ux.microsoft.com>
To: Paul Moore <paul@...l-moore.com>,
	James Morris <jmorris@...ei.org>,
	"Serge E. Hallyn" <serge@...lyn.com>,
	Alexei Starovoitov <ast@...nel.org>,
	Daniel Borkmann <daniel@...earbox.net>,
	John Fastabend <john.fastabend@...il.com>,
	Andrii Nakryiko <andrii@...nel.org>,
	Martin KaFai Lau <martin.lau@...ux.dev>,
	Eduard Zingerman <eddyz87@...il.com>,
	Song Liu <song@...nel.org>,
	Yonghong Song <yonghong.song@...ux.dev>,
	KP Singh <kpsingh@...nel.org>,
	Stanislav Fomichev <sdf@...ichev.me>,
	Hao Luo <haoluo@...gle.com>,
	Jiri Olsa <jolsa@...nel.org>,
	Stephen Smalley <stephen.smalley.work@...il.com>,
	Ondrej Mosnacek <omosnace@...hat.com>,
	Mykola Lysenko <mykolal@...com>,
	Shuah Khan <shuah@...nel.org>,
	Blaise Boscaccy <bboscaccy@...ux.microsoft.com>,
	Kumar Kartikeya Dwivedi <memxor@...il.com>,
	Matt Bobrowski <mattbobrowski@...gle.com>,
	Xu Kuohai <xukuohai@...wei.com>,
	linux-kernel@...r.kernel.org,
	linux-security-module@...r.kernel.org,
	bpf@...r.kernel.org,
	selinux@...r.kernel.org,
	linux-kselftest@...r.kernel.org
Subject: [PATCH v5 bpf-next 0/2] security: Propagate caller information in bpf hooks

Hello,

While trying to implement an eBPF gatekeeper program, we ran into an
issue whereas the LSM hooks are missing some relevant data.

Certain subcommands passed to the bpf() syscall can be invoked from
either the kernel or userspace. Additionally, some fields in the
bpf_attr struct contain pointers, and depending on where the
subcommand was invoked, they could point to either user or kernel
memory. One example of this is the bpf_prog_load subcommand and its
fd_array. This data is made available and used by the verifier but not
made available to the LSM subsystem. This patchset simply exposes that
information to applicable LSM hooks.

Change list:
- v4 -> v5
  - merge v4 selftest breakout patch back into a single patch
  - change "is_kernel" to "kernel"
  - add selftest using new kernel flag
- v3 -> v4
  - split out selftest changes into a separate patch
- v2 -> v3
  - reorder params so that the new boolean flag is the last param
  - fixup function signatures in bpf selftests
- v1 -> v2
  - Pass a boolean flag in lieu of bpfptr_t

Revisions:
- v4
  https://lore.kernel.org/bpf/20250304203123.3935371-1-bboscaccy@linux.microsoft.com/
- v3
  https://lore.kernel.org/bpf/20250303222416.3909228-1-bboscaccy@linux.microsoft.com/
- v2
  https://lore.kernel.org/bpf/20250228165322.3121535-1-bboscaccy@linux.microsoft.com/
- v1
  https://lore.kernel.org/bpf/20250226003055.1654837-1-bboscaccy@linux.microsoft.com/


Blaise Boscaccy (2):
  security: Propagate caller information in bpf hooks
  selftests/bpf: Add a kernel flag test for LSM bpf hook

 include/linux/lsm_hook_defs.h                 |  6 +--
 include/linux/security.h                      | 12 +++---
 kernel/bpf/syscall.c                          | 10 ++---
 security/security.c                           | 15 ++++---
 security/selinux/hooks.c                      |  6 +--
 .../selftests/bpf/prog_tests/kernel_flag.c    | 43 +++++++++++++++++++
 .../selftests/bpf/progs/rcu_read_lock.c       |  3 +-
 .../bpf/progs/test_cgroup1_hierarchy.c        |  4 +-
 .../selftests/bpf/progs/test_kernel_flag.c    | 32 ++++++++++++++
 .../bpf/progs/test_kfunc_dynptr_param.c       |  6 +--
 .../selftests/bpf/progs/test_lookup_key.c     |  2 +-
 .../selftests/bpf/progs/test_ptr_untrusted.c  |  2 +-
 .../bpf/progs/test_task_under_cgroup.c        |  2 +-
 .../bpf/progs/test_verify_pkcs7_sig.c         |  2 +-
 14 files changed, 112 insertions(+), 33 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/kernel_flag.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_kernel_flag.c

-- 
2.48.1

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