Since commit: 24a3cbfa73
ueventd is attempting to relabel devices on calls to
make_device() when the device already exists. However, it
should only be called if the contexts for relabelfrom and
relabelto are different.
When this condition occurs, one will see denials like this:
[ 14.409448] type=1400 audit(978307239.225:26): avc: denied { relabelfrom } for pid=1572 comm="ueventd" name="ttyS0" dev="tmpfs" ino=9613 scontext=u:r:ueventd:s0 tcontext=u:object_r:hci_attach_dev:s0 tclass=chr_file permissive=1
[ 14.428107] type=1400 audit(978307239.225:27): avc: denied { relabelto } for pid=1572 comm="ueventd" name="ttyS0" dev="tmpfs" ino=9613 scontext=u:r:ueventd:s0 tcontext=u:object_r:hci_attach_dev:s0 tclass=chr_file permissive=1
Bug: 29106809
Change-Id: I2105b169206f0b26420f3c4b0ba5c49aeb98da92
Signed-off-by: William Roberts <william.c.roberts@intel.com>
Currently, ueventd.rc files only support /sys/devices/... paths
and don't support symlinked paths, specifically /sys/class/...
Supporting the class paths is necessary to have non-hardware
dependent paths. Some subsystems like IIO use /sys/bus/iio/, so
support that as well.
Change-Id: I29f3bf67b41664d1d75ac1820c46e13afe336d56
Signed-off-by: Rob Herring <robh@kernel.org>
fixup_sys_perms does the same matching as the function perm_path_matches
other than the leading '/sys'. Adjust the path and use the common
matching function. Replace the fixed length C strings with std::string.
Change-Id: Ic09d91aa4ac1f1096018617537d782b82ee9ef63
Signed-off-by: Rob Herring <robh@kernel.org>
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>
In function 'load_firmware', parameter 'buf' passed to 'write'
is wrong. To fix it, use android::base::WriteFully to replace.
Change-Id: I13f79bdc9be9e5eb669f6bd975535b1dce965ef0
Signed-off-by: Biao Lu <biao.lu@intel.com>
d34e407aeb removed support for
running with SELinux completely disabled. SELinux must either be
in permissive or enforcing mode now.
Remove unnecessary calls to is_selinux_enabled(). It always returns
true now.
Change-Id: Ife3156b74b13b2e590afe4accf716fc7776567e5
Certain platforms list their platform devices with a path other than
the current /devices or /devices/platform. Additionally, sometimes
these paths are a platform device themselves. An example are devices
with a path /devices/soc.0/... where /devices/soc.0 is also a platform
devices.
Instead of continuing to special case these path prefixes, we can
consider the entire path, given that no mmc or usb devices create
platform devices as subdevices, which they should not by their very
nature.
This keeps the symlinks for block devices named identically for
current platform devices and places them in /dev/block/<full path to
device> for devices in locations other than /devices or
/devices/platform, eg /dev/block/platform/soc.0/7824900.sdhci
This keeps the symlinks for character deviced named identically for
all cases.
Change-Id: Ifc8eedf1086db1826dbc8f7e96cdfcfa5da876b3
Also don't manually set FD_CLOEXEC on a socket that's always opened
with SOCK_CLOEXEC. (None of the other callers to the function do this.)
Also move locals to where they're first used to help prevent more of this
kind of breakage.
Change-Id: I1ba7cd9400f53508dffb51a2bbf9d491ae647f26
Also make important events in init's life NOTICE rather than INFO,
and ensure that NOTICE events actually make it to the kernel log.
Also fix the logging so that if you have a printf format string
error, the compiler now catches it.
Also give messages from init, ueventd, and watchdogd distinct tags.
(Previously they'd all call themselves "init", and dmesg doesn't
include pids, so you couldn't untangle them.)
Also include the tag in SELinux messages.
Bug: 19544788
Change-Id: Ica6daea065bfdb80155c52c0b06f346a7df208fe
This isn't particularly useful in and of itself, but it does introduce the
first (trivial) unit test, improves the documentation (including details
about how to debug init crashes), and made me aware of how unpleasant the
existing parser is.
I also fixed a bug in passing --- unless you thought the "peboot" and "pm"
commands were features...
Bug: 19217569
Change-Id: I6ab76129a543ce3ed3dab52ef2c638009874c3de
