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chromium / chromiumos / platform / minijail / refs/heads/release-R113-15393.B
commit3ee4393c2717e5c8c2b7e7e2188b833314142471[log] [tgz]
authorBen Scarlato <akhna@google.com>Tue Mar 21 18:47:31 2023
committerChromeos LUCI <chromeos-scoped@luci-project-accounts.iam.gserviceaccount.com>Thu Mar 23 01:22:33 2023
treea7059ba0a05fbf9b2f1a5d52a30303257cc40bb7
parent13be56d79718425a60173f61f8174669d9cc8930 [diff]
minijail: use set_preload_path() to avoid incorrect preload path

This adds set_preload_path() to unit tests that can otherwise fail when the size of the minijail struct in the local preload does not match the size of the struct in the system preload.

BUG=b:274627951
TEST=security.Minijail*
TEST=verify that unit tests still pass in ChromeOS chroot if a new field is added to `struct minijail`

Change-Id: Ie0bf9ecc1edb7896623a1b8d205fa0c6a9c0808d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/minijail/+/4358377
Commit-Queue: Ben Scarlato <akhna@google.com>
Auto-Submit: Ben Scarlato <akhna@google.com>
Tested-by: Ben Scarlato <akhna@google.com>
Reviewed-by: Allen Webb <allenwebb@google.com>
1 file changed
tree: a7059ba0a05fbf9b2f1a5d52a30303257cc40bb7
  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@.