Google Git
Sign in
android / platform / external / minijail / 84ffabcf488bf0935f00930a9a23bbce1f34d79f
commit84ffabcf488bf0935f00930a9a23bbce1f34d79f[log] [tgz]
authorStéphane Lesimple <[email protected]>Fri Feb 14 20:33:34 2020 +0100
committerTreehugger Robot <[email protected]>Fri Mar 13 18:19:51 2020 +0000
tree3211a13fd53a562cc8135cbacf1a57067680c032
parent2b12228001b843327eea78230295dff9813e6b16 [diff]
fix lookup_group/lookup_user for ERANGE cases

lookup_group uses getgrnam_r to lookup a group's gid, and
lookup_user uses getpwnam_r to lookup a user's uid.

Those 2 functions can return ERANGE if the passed buffer is
too small to hold the group (or user) information. Fix the
code logic by using sysconf(_SC_GETGR_R_SIZE_MAX) and
sysconf(_SC_GETPW_R_SIZE_MAX) only as hints for the minimal
buffer size to use instead of the max size.

When ERANGE is returned, retry with a buffer twice as big,
until we get valid data, up to 1 MiB.

Change-Id: Id91232e0faffa47356d80d487442d73bc907af98
1 file changed
tree: 3211a13fd53a562cc8135cbacf1a57067680c032
  1. .github/
  2. examples/
  3. linux-x86/
  4. test/
  5. tools/
  6. .clang-format
  7. .gitignore
  8. Android.bp
  9. arch.h
  10. bpf.c
  11. bpf.h
  12. build.rs
  13. Cargo.toml
  14. CleanSpec.mk
  15. common.mk
  16. CPPLINT.cfg
  17. dump_constants.cc
  18. elfparse.c
  19. elfparse.h
  20. gen_constants-inl.h
  21. gen_constants.c
  22. gen_constants.sh
  23. gen_syscalls.c
  24. gen_syscalls.sh
  25. get_googletest.sh
  26. HACKING.md
  27. lib.rs
  28. libconstants.h
  29. libminijail-private.h
  30. libminijail.c
  31. libminijail.h
  32. libminijail.pc.in
  33. libminijail.rs
  34. libminijail_unittest.cc
  35. libminijailpreload.c
  36. libsyscalls.h
  37. LICENSE
  38. Makefile
  39. minijail0.1
  40. minijail0.5
  41. minijail0.c
  42. minijail0_cli.c
  43. minijail0_cli.h
  44. minijail0_cli_unittest.cc
  45. MODULE_LICENSE_BSD
  46. navbar.md
  47. NOTICE
  48. OWNERS
  49. OWNERS.rust
  50. parse_seccomp_policy.cc
  51. platform2_preinstall.sh
  52. PRESUBMIT.cfg
  53. PREUPLOAD.cfg
  54. README.md
  55. RELEASE.md
  56. scoped_minijail.h
  57. setup.py
  58. signal_handler.c
  59. signal_handler.h
  60. syscall_filter.c
  61. syscall_filter.h
  62. syscall_filter_unittest.cc
  63. syscall_filter_unittest_macros.h
  64. syscall_wrapper.c
  65. syscall_wrapper.h
  66. system.c
  67. system.h
  68. system_unittest.cc
  69. TEST_MAPPING
  70. testrunner.cc
  71. util.c
  72. util.h
  73. util_unittest.cc
README.md

Minijail

The Minijail homepage and main repo is https://android.googlesource.com/platform/external/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 Chrome OS 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://android.googlesource.com/platform/external/minijail
$ cd minijail

Releases are tagged as linux-vXX: https://android.googlesource.com/platform/external/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 Chromium OS 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