There is a race in ueventd's coldboot procedure that permits creation
of device block nodes before platform devices are registered. This happens
when the kernel sends events for adding block devices during ueventd's
coldboot /sys walk.
In this case the device node links used to compute the SELinux context
are not known and the node is created under the generic context:
u:object_r:block_device:s0.
A second add event for block device nodes is triggered after the platform
devices are handled by ueventd and the SELinux context is correctly computed
but the mknod call fails because the node already exists. This patch handles
this error case and updates the node's security context.
The race is introduced by the uevent sent from the sdcard device probe
function. The issue appears when this uevent is triggered during ueventd's
coldboot procedure but before the /sys/devices recursive walk reached the
corresponding sdcard platform device path.
The backtrace looks something like:
1. ueventd_main()
2. device_init()
3. coldboot("/sys/devices");
4. do_coldboot()
5. handle_device_fd()
6. handle_device_event()
6.1 handle_block_device_event()
6.2 handle_platform_device_event()
Because handle_device_fd() reads all events from the netlink socket it may
handle the add events for the sdcard partition nodes send occasionally by the
kernel during coldboot /sys walk procedure.
If handle_device_event() continues with handle_block_device_event()
before handle_platform_device_event() registers the sdcard platform device then
handle_block_device_event() will create device nodes without knowing all block
device symlinks (get_block_device_symlinks()):
1. handle_device(path=/dev/block/mmcblk0p3, links = NULL)
2. make_device(path=/dev/block/mmcblk0p3, links = NULL)
3. selabel_lookup_best_match(path=/dev/block/mmcblk0p3, links = NULL)
returns the default context (u:object_r:block_device:s0) for
/dev/block/mmcblk0p3 instead of more specific context like:
u:object_r:boot_block_device:s0
4. setfscreatecon(u:object_r:block_device:s0)
5. mknod(/dev/block/mmcblk0p3)
So the node is create with the wrong context. Afterwards the coldboot /sys walk
continues and make_device() will be called with correct path and links.
But even if the secontext is computed correctly this time it will not be
applied to the device node because mknod() fails.
I see this issue randomly appearing (one time in 10 reboots) on a Minnoboard
Turbot with external sdcard as the boot device.
BUG=28388946
Change-Id: I96e239af29d82b753e5d349b3ecefaad09edee87
Signed-off-by: Mihai Serban <mihai.serban@intel.com>
Most of the system/core/include/log/log.h file uses the C99 syntax of
variadic macros (that is, '...' in parameter list and __VA_ARGS__
in arguments). Except for andoid_printLog and android_printAssert
which still uses GCC custom extension syntax.
Switched the remaining macros to use C99 syntax. GCC extension syntax
makes my editor's code parser puke.
BUG: None
Change-Id: Ia6ebc0f2044b64182c425b179da0229c7046be4a
am: c296440
* commit 'c2964402b6ff91126bbbf7dd453adca40a13bd64':
adb: decrease the number of fds used in fd_count test.
Change-Id: Id078e3b319bdd8591b78898e543a636f9eac6bf0
https://android-review.googlesource.com/#/c/210646/ added a
has_shell_protocol() function but the test_device.py tests were still
trying to use the now-missing SHELL_PROTOCOL_FEATURE constant.
This CL just switches test_device.py to correctly use the
has_shell_protocol() method.
Change-Id: Ie0a2f0dc07529843d25051a01e08fb677551a4e1
Test: `python -m unittest discover -v` on devices with and without
the shell protocol.
Insert a space between 'if'/'while' and their clause.
Also insert a space after ',' for arguments.
This was done with clang-format.
Bug: None
Change-Id: I5315eba3d5d8ac68996a373dc7c8e1bc45165824
Currently, 'ps' will segfault when called with '--ppid' and no argument.
Make it return an error instead.
Bug: 28383024
Change-Id: I71f2d1ba9502996ae75b17605234eb99ebb589f2
We previously relied on the fact that target sdk version 0
implies system_server, which is not true, target sdk version
may be set to 0 for other apps and it means 1 - the earliest
version of android. This change enables namespaces for
apps targeting all sdk version and for system_server.
Bug: http://b/27702070
Change-Id: I16fbdeb6868c7035aec71132c80c150c08ea2cc3
