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chromium / chromiumos / platform / minijail / refs/heads/stabilize-15446.B
commit1c2fa0af507708ae931a9e5563fd31b5bae48226[log] [tgz]
authorBen Scarlato <akhna@google.com>Thu Apr 27 14:54:00 2023
committerChromeos LUCI <chromeos-scoped@luci-project-accounts.iam.gserviceaccount.com>Tue May 02 01:33:29 2023
tree7ec8f9fb044801b185e0f4b6d728d3a4c317a00c
parent238e67afe3e1f7a6c3de2d5531a5ec2844eb7083 [diff]
minijail: call setup_fs_rules_fd() early for API users

This is needed for API users who directly use minijail_enter(),
rather than any of the minijail_run*() variants or minijail0.

BUG=b:279751164
TEST=security.Minijail*

Change-Id: I2867c314af2face24c7fbd0a7a3d50a6fc847ca0
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/minijail/+/4484359
Auto-Submit: Ben Scarlato <akhna@google.com>
Commit-Queue: Ben Scarlato <akhna@google.com>
Tested-by: Ben Scarlato <akhna@google.com>
Reviewed-by: Allen Webb <allenwebb@google.com>
3 files changed
tree: 7ec8f9fb044801b185e0f4b6d728d3a4c317a00c
  1. .github/
  2. examples/
  3. linux-x86/
  4. policies/
  5. rust/
  6. test/
  7. tools/
  8. .clang-format
  9. .gitignore
  10. Android.bp
  11. arch.h
  12. bpf.c
  13. bpf.h
  14. CleanSpec.mk
  15. common.mk
  16. config_parser.c
  17. config_parser.h
  18. config_parser_unittest.cc
  19. CPPLINT.cfg
  20. DIR_METADATA
  21. dump_constants.cc
  22. elfparse.c
  23. elfparse.h
  24. gen_constants-inl.h
  25. gen_constants.c
  26. gen_constants.sh
  27. gen_syscalls-inl.h
  28. gen_syscalls.c
  29. gen_syscalls.sh
  30. get_googletest.sh
  31. HACKING.md
  32. landlock.h
  33. landlock_util.c
  34. landlock_util.h
  35. libconstants.h
  36. libminijail-private.h
  37. libminijail.c
  38. libminijail.h
  39. libminijail.pc.in
  40. libminijail_unittest.cc
  41. libminijailpreload.c
  42. libsyscalls.h
  43. LICENSE
  44. Makefile
  45. METADATA
  46. minijail0.1
  47. minijail0.5
  48. minijail0.c
  49. minijail0.sh
  50. minijail0_cli.c
  51. minijail0_cli.h
  52. minijail0_cli_unittest.cc
  53. MODULE_LICENSE_BSD
  54. navbar.md
  55. NOTICE
  56. OWNERS
  57. OWNERS_GENERAL
  58. parse_seccomp_policy.cc
  59. platform2_preinstall.sh
  60. PRESUBMIT.cfg
  61. PREUPLOAD.cfg
  62. README.md
  63. RELEASE.md
  64. scoped_minijail.h
  65. setup.py
  66. signal_handler.c
  67. signal_handler.h
  68. syscall_filter.c
  69. syscall_filter.h
  70. syscall_filter_unittest.cc
  71. syscall_filter_unittest_macros.h
  72. syscall_wrapper.c
  73. syscall_wrapper.h
  74. system.c
  75. system.h
  76. system_unittest.cc
  77. TEST_MAPPING
  78. test_util.cc
  79. test_util.h
  80. testrunner.cc
  81. unittest_util.h
  82. util.c
  83. util.h
  84. util_unittest.cc
README.md

Minijail

The Minijail homepage is https://google.github.io/minijail/.

The main source repo is https://chromium.googlesource.com/chromiumos/platform/minijail.

There might be other copies floating around, but this is the official one!

What is it?

Minijail is a sandboxing and containment tool used in ChromeOS and Android. It provides an executable that can be used to launch and sandbox other programs, and a library that can be used by code to sandbox itself.

Getting the code

You're one git clone away from happiness.

$ git clone https://chromium.googlesource.com/chromiumos/platform/minijail
$ cd minijail

Releases are tagged as linux-vXX: https://chromium.googlesource.com/chromiumos/platform/minijail/+refs

Building

See the HACKING.md document for more details.

Release process

See the RELEASE.md document for more details.

Additional tools

See the tools/README.md document for more details.

Contact

We've got a couple of contact points.

Talks and presentations

The following talk serves as a good introduction to Minijail and how it can be used.

Video, slides.

Example usage

The ChromiumOS project has a comprehensive sandboxing document that is largely based on Minijail.

After you play with the simple examples below, you should check that out.

Change root to any user

# id
uid=0(root) gid=0(root) groups=0(root),128(pkcs11)
# minijail0 -u jorgelo -g 5000 /usr/bin/id
uid=72178(jorgelo) gid=5000(eng) groups=5000(eng)

Drop root while keeping some capabilities

# minijail0 -u jorgelo -c 3000 -- /bin/cat /proc/self/status
Name: cat
...
CapInh: 0000000000003000
CapPrm: 0000000000003000
CapEff: 0000000000003000
CapBnd: 0000000000003000

Historical notes

Q. “Why is it called minijail0?”

A. It is minijail0 because it was a rewrite of an earlier program named minijail, which was considerably less mini, and in particular had a dependency on libchrome (the ChromeOS packaged version of Chromium's //base). We needed a new name to not collide with the deprecated one.

We didn‘t want to call it minijail2 or something that would make people start using it before we were ready, and it was also concretely less since it dropped libbase, etc. Technically, we needed to be able to fork/preload with minimal extra syscall noise which was too hard with libbase at the time (onexit handlers, etc that called syscalls we didn’t want to allow). Also, Elly made a strong case that C would be the right choice for this for linking and ease of controlled surprise system call use.

https://crrev.com/c/4585/ added the original implementation.

Source: Conversations with original authors, ellyjones@ and wad@.