[v4,00/11] Add seccomp notifier ioctl that enables adding fds

Message

Kees Cook June 16, 2020, 3:25 a.m. UTC

Hello!

This is a bit of thread-merge between [1] and [2]. tl;dr: add a way for
a seccomp user_notif process manager to inject files into the managed
process in order to handle emulation of various fd-returning syscalls
across security boundaries. Containers folks and Chrome are in need
of the feature, and investigating this solution uncovered (and fixed)
implementation issues with existing file sending routines.

I intend to carry this in the seccomp tree, unless someone has objections.
:) Please review and test!

-Kees

[1] https://lore.kernel.org/lkml/[e-mail]/
[2] https://lore.kernel.org/lkml/[e-mail]/

Kees Cook (9):
  net/scm: Regularize compat handling of scm_detach_fds()
  fs: Move __scm_install_fd() to __fd_install_received()
  fs: Add fd_install_received() wrapper for __fd_install_received()
  pidfd: Replace open-coded partial fd_install_received()
  fs: Expand __fd_install_received() to accept fd
  selftests/seccomp: Make kcmp() less required
  selftests/seccomp: Rename user_trap_syscall() to user_notif_syscall()
  seccomp: Switch addfd to Extensible Argument ioctl
  seccomp: Fix ioctl number for SECCOMP_IOCTL_NOTIF_ID_VALID

Sargun Dhillon (2):
  seccomp: Introduce addfd ioctl to seccomp user notifier
  selftests/seccomp: Test SECCOMP_IOCTL_NOTIF_ADDFD

 fs/file.c                                     |  65 ++++
 include/linux/file.h                          |  16 +
 include/uapi/linux/seccomp.h                  |  25 +-
 kernel/pid.c                                  |  11 +-
 kernel/seccomp.c                              | 181 ++++++++-
 net/compat.c                                  |  55 ++-
 net/core/scm.c                                |  50 +--
 tools/testing/selftests/seccomp/seccomp_bpf.c | 350 +++++++++++++++---
 8 files changed, 618 insertions(+), 135 deletions(-)

Comments

Sargun Dhillon June 18, 2020, 10:16 p.m. UTC | #1

On Mon, Jun 15, 2020 at 08:25:13PM -0700, Kees Cook wrote:
> Hello!
> 
> This is a bit of thread-merge between [1] and [2]. tl;dr: add a way for
> a seccomp user_notif process manager to inject files into the managed
> process in order to handle emulation of various fd-returning syscalls
> across security boundaries. Containers folks and Chrome are in need
> of the feature, and investigating this solution uncovered (and fixed)
> implementation issues with existing file sending routines.
> 
> I intend to carry this in the seccomp tree, unless someone has objections.
> :) Please review and test!
> 
> -Kees
> 
> [1] https://lore.kernel.org/lkml/[e-mail]/
> [2] https://lore.kernel.org/lkml/[e-mail]/
> 
> Kees Cook (9):
>   net/scm: Regularize compat handling of scm_detach_fds()
>   fs: Move __scm_install_fd() to __fd_install_received()
>   fs: Add fd_install_received() wrapper for __fd_install_received()
>   pidfd: Replace open-coded partial fd_install_received()
>   fs: Expand __fd_install_received() to accept fd
>   selftests/seccomp: Make kcmp() less required
>   selftests/seccomp: Rename user_trap_syscall() to user_notif_syscall()
>   seccomp: Switch addfd to Extensible Argument ioctl
>   seccomp: Fix ioctl number for SECCOMP_IOCTL_NOTIF_ID_VALID
> 
This looks much cleaner than the original patchset. Thanks.

Reviewed-by: Sargun Dhillon <[e-mail]>

on the pidfd, change fs* changes.

> Sargun Dhillon (2):
>   seccomp: Introduce addfd ioctl to seccomp user notifier
>   selftests/seccomp: Test SECCOMP_IOCTL_NOTIF_ADDFD
> 
>  fs/file.c                                     |  65 ++++
>  include/linux/file.h                          |  16 +
>  include/uapi/linux/seccomp.h                  |  25 +-
>  kernel/pid.c                                  |  11 +-
>  kernel/seccomp.c                              | 181 ++++++++-
>  net/compat.c                                  |  55 ++-
>  net/core/scm.c                                |  50 +--
>  tools/testing/selftests/seccomp/seccomp_bpf.c | 350 +++++++++++++++---
>  8 files changed, 618 insertions(+), 135 deletions(-)
> 
> -- 
> 2.25.1
>