mbox series

[v7,bpf-next,0/2] security: Propagate caller information in bpf hooks

Message ID 20250310221737.821889-1-bboscaccy@linux.microsoft.com (mailing list archive)
Headers show
Series security: Propagate caller information in bpf hooks | expand

Message

Blaise Boscaccy March 10, 2025, 10:17 p.m. UTC 
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:
- v6 -> v7
  - use gettid/pid in lieu of getpid/tgid in test condition
- v5 -> v6
  - fix regression caused by is_kernel renaming
  - simplify test logic
- 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:
- v6
  https://lore.kernel.org/bpf/20250308013314.719150-1-bboscaccy@linux.microsoft.com/
- v5
  https://lore.kernel.org/bpf/20250307213651.3065714-1-bboscaccy@linux.microsoft.com/
- 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    | 28 ++++++++++++
 .../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, 108 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

Comments

patchwork-bot+netdevbpf@kernel.org March 11, 2025, 11:40 a.m. UTC | #1 
Hello:

This series was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@kernel.org>:

On Mon, 10 Mar 2025 15:17:10 -0700 you wrote:
> 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.
> 
> [...]

Here is the summary with links:
  - [v7,bpf-next,1/2] security: Propagate caller information in bpf hooks
    https://git.kernel.org/bpf/bpf-next/c/a8cd03532fc9
  - [v7,bpf-next,2/2] selftests/bpf: Add a kernel flag test for LSM bpf hook
    https://git.kernel.org/bpf/bpf-next/c/f563314d7293

You are awesome, thank you!