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15 commits

Author SHA1 Message Date
Tom Cherry
0b2a011cc4 logd: don't drop user/groups/capabilities/priority in drop_privs()
On Android, unlike POSIX, groups and capabilities are able to be set
per thread.  This is useless however, since threads are not a security
boundary.  This change drops the logic to set groups and capabilities
per thread and instead leaves all threads running with the initial
user and groups.

This does still drop some capabilities if they're unneeded due to
features being disabled.

This also moves the setpriority() call from code into the init script.

Test: logd runs with the expected user/groups and with the expected
      capabilities and priority without any errors

Change-Id: Ibb0e529ea1574a2b8ec391a2678504ca9fbe19be
2019-06-07 15:52:27 +00:00
Nick Kralevich
be5e446791 introduce auditctl and use it to configure SELinux throttling
In an effort to ensure that our development community does not
introduce new code without corresponding SELinux changes, Android
closely monitors the number of SELinux denials which occur during
boot. This monitoring occurs both in treehugger, as well as various
dashboards. If SELinux denials are dropped during early boot, this
could result in non-determinism for the various SELinux treehugger
tests.

Introduce /system/bin/auditctl. This tool, model after
https://linux.die.net/man/8/auditctl , allows for configuring the
throttling rate for the kernel auditing system.

Remove any throttling from early boot. This will hopefully reduce
treehugger flakiness by making denial generation more predictible
during early boot.

Reapply the throttling at boot complete, to avoid denial of service
attacks against the auditing subsystem.

Delete pre-existing unittests for logd / SELinux integration. It's
intended that all throttling decisions be made in the kernel, and
shouldn't be a concern of logd.

Bug: 118815957
Test: Perform an operation which generates lots of SELinux denials,
      and count how many occur before and after the time period.
Change-Id: I6c787dbdd4a28208dc854b543e1727ae92e5eeed
2019-04-09 13:19:08 -07:00
Luis Hector Chavez
d32c36c961 logd: Move the capabilities from file based to ambient
This change moves logd's capabilities from being file based to being set
by init through ambient capabilities.

Bug: 62845925
Test: sailfish:/ # grep Cap /proc/`pidof logd`/status
      CapInh: 0000000000000000
      CapPrm: 0000000440000000
      CapEff: 0000000440000000
      CapBnd: 0000000440000040
      CapAmb: 0000000000000000
      $ capsh --decode=0x440000040
      0x440000040=cap_setgid,cap_audit_control,cap_syslog
Test: liblog-unit-tests, logd-unit-tests, logcat-unit-tests
Change-Id: I28c7c4ad37ad5eafd399aef78c303ce31298a9ef
2018-06-11 10:04:11 -07:00
Joel Galenson
fef8644f8d Remove unnecessary restorecon.
Now that creating a symlink in init automatically sets its
context, we do not need to call restorecon manually.

Bug: 69965807
Test: Booted device and tested wifi and camera.
Change-Id: I0863198f2c2bfce79566b5320c7ef035698f3afb
2017-11-30 15:39:43 -08:00
Mark Salyzyn
54d8ff1121 logd: add "+passcred" for logdw socket
Tell init to set SO_PASSCRED on the socket before bind() and handoff.

Test: gtest logd-unit-test --gtest_filter=logd.statistics right after boot
Bug: 37985222
Change-Id: I318969ee3241834e5326233aabd97e52ef505969
2017-05-08 16:19:48 -07:00
Mark Salyzyn
d392ac160c logd: refine permissions to access /data/system/packages.list
Refine DAC security surrounding logd.daemon worker thread and add a
positive test for logd failure to access /data/system/packages.list.

- Add AID_PACKAGE_INFO to groups of worker thread.
- Move AID_SYSTEM to groups, setgid to AID_LOGD.
- Do not drop capabilities until after setting the uid and gids.
- Add a test that is part of logd.statistics test to check when
  packagelistparser appears broken.
- If /data/system/packages.list is encrypted, ensure we do not pick
  up the existing inode to ensure strong positive when finding access
  problems.
- Replace all occurrences of NULL with nullptr in gTest code for
  compliance with best practices.

Test: gTest logd-unit-tests --gtest_filter=logd.statistics
      (expect consistent failure, later CLs fix)
Bug: 37751120
Bug: 36645158
Change-Id: I01b26fe5e25203246ae432d272c8daa9c07cab54
2017-05-03 14:35:14 -07:00
Mark Salyzyn
61e9ce6709 logd: add getEventTag command and service
Will register a new event tag by name and format, and return an
event-log-tags format response with the newly allocated tag.
If format is not specified, then nothing will be recorded, but
a pre-existing named entry will be listed. If name and format are
not specified, list all dynamic entries. If name=* list all
event log tag entries.

Stickiness through logd crash will be managed with the tmpfs file
/dev/event-log-tags and through a reboot with add_tag entries in
the pmsg last logcat event log. On debug builds we retain a
/data/misc/logd/event-log-tags file that aids stickiness and that
can be picked up by the bugreport.

If we detect truncation damage to /dev/event-log-tags, or to
/data/misc/logd/event-log-tags, rebuild file with a new first line
signature incorporating the time so mmap'd readers of the file can
detect the possible change in shape and order.

Manual testing:

Make sure nc (netcat) is built for the target platform on the host:
$ m nc

Then the following can be used to issue a request on the platform:
$ echo -n 'getEventTag name=<name> format="<format>"\0EXIT\0' |
> nc -U /dev/socket/logd

Test: gTest logd-unit-test --gtest_filter=getEventTag*
Bug: 31456426
Change-Id: I5dacc5f84a24d52dae09cca5ee1a3a9f9207f06d
2017-02-02 14:24:18 -08:00
Mark Salyzyn
77fdb22cf6 logd: start logd service in logd uid
Test: gTest logd-unit-tests, liblog-unit-tests and logcat-unit-tests
      Manual inspect grep '^Cap' /proc/<tid>/status for correct capabilities
Bug: 32450474
Change-Id: Ia6a3872901969a789d4309d410dbfd5f5d17b3ce
2016-11-03 13:34:27 -07:00
Mark Salyzyn
5b44340acb logd: start logd services in logd gid
logd - start as root:logd+system+readproc
logd-reinit - start as logd:logd

ToDo: start as logd:logd+system+readproc (libminijail)
Test: gTest logd-unit-tests, liblog-unit-tests and logcat-unit-tests
Bug: 32450474
Change-Id: I42c806ca1730a7f9eb9e34f064ae31a2ef9fc678
2016-11-03 13:34:27 -07:00
Mark Salyzyn
e0b8ccd1a3 logd: inherit android_get_control_file()
Setup and then collect from the environment /proc/kmsg and /dev/kmsg
file descriptors. Do not do so for logcat --reinit.

Test: gTest logd-unit-tests, liblog-unit-tests and logcat-unit-tests
Bug: 32450474
Change-Id: Ied537ca561fcd4e71a9ad9c57398a23ba23f6ced
2016-11-03 13:34:27 -07:00
Mark Salyzyn
0604f6fbae init.rc: too many start logd
Bug: 26934873
Change-Id: Ia00da6253a50bedc8ba825df1cf641b86cdebeed
2016-02-02 16:01:17 -08:00
Nick Kralevich
c39ba5ae32 Enable hidepid=2 on /proc
Add the following mount options to the /proc filesystem:

  hidepid=2,gid=3009

This change blocks /proc access unless you're in group 3009
(aka AID_READPROC).

Please see
  https://github.com/torvalds/linux/blob/master/Documentation/filesystems/proc.txt
for documentation on the hidepid option.

hidepid=2 is preferred over hidepid=1 since it leaks less information
and doesn't generate SELinux ptrace denials when trying to access
/proc without being in the proper group.

Add AID_READPROC to processes which need to access /proc entries for
other UIDs.

Bug: 23310674
Change-Id: I22bb55ff7b80ff722945e224845215196f09dafa
2015-11-09 09:08:46 -08:00
Tom Cherry
984bd8323d resolved conflicts for 5caca3dd to mnc-dr-dev-plus-aosp
Change-Id: I773e514a8232b77cdd566dc36c9efc4e15f206f0
2015-09-21 14:25:34 -07:00
Tom Cherry
b267af9808 update bundled rc files to their contents from rootdir/init.rc
Bug 23186545

Change-Id: Ieb03ba89db2dee0365ae346295207ddfd29bd2b7
(cherry picked from commit 297991b324)
2015-08-21 22:10:17 +00:00
Tom Cherry
20391b1de5 bundle init.rc contents with its service
Bug: 23186545
Change-Id: I52616b8ab1165fdef716f9b8f958665f2308c12e
2015-08-21 10:14:43 -07:00