a523aaca12
Switch the kernel and init domains from unconfined_domain()
to permissive_or_unconfined() so that we can start collecting
and addressing denials in -userdebug/-eng builds.
Also begin to address denials for kernel and init seen after
making this switch.
I intentionally did not allow the following denials on hammerhead:
avc: denied { create } for pid=1 comm="init" name="memory.move_charge_at_immigrate" scontext=u:r:init:s0 tcontext=u:object_r:init_tmpfs:s0 tclass=file
avc: denied { open } for pid=1 comm="init" name="memory.move_charge_at_immigrate" dev="tmpfs" ino=6550 scontext=u:r:init:s0 tcontext=u:object_r:init_tmpfs:s0 tclass=file
These occur when init.rc does:
write /sys/fs/cgroup/memory/memory.move_charge_at_immigrate 1
because the prior command to mount the cgroup failed:
mount cgroup none /sys/fs/cgroup/memory memory
I think this is because that cgroup is not enabled in the
kernel configuration. If the cgroup mount succeeded,
then this would have been a write to a cgroup:file and
would have been allowed already.
Change-Id: I9d7e31bef6ea91435716aa4312c721fbeaeb69c0
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
70 lines
2.6 KiB
Text
70 lines
2.6 KiB
Text
# Life begins with the kernel.
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type kernel, domain;
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permissive_or_unconfined(kernel)
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allow kernel self:capability sys_nice;
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# Run /init before we have switched domains.
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allow kernel rootfs:file execute_no_trans;
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# /dev/__null__ node created by init prior to policy load.
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allow kernel tmpfs:chr_file rw_file_perms;
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# setcon to init domain.
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allow kernel self:process setcurrent;
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allow kernel init:process dyntransition;
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# cgroup filesystem initialization prior to setting the cgroup root directory label.
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allow kernel unlabeled:dir search;
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# Mount usbfs.
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allow kernel usbfs:filesystem mount;
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# init direct restorecon calls prior to switching to init domain
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# /dev and /dev/socket
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allow kernel tmpfs:dir relabelfrom;
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allow kernel { device socket_device }:dir relabelto;
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# /dev/__properties__
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allow kernel tmpfs:file relabelfrom;
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allow kernel properties_device:file relabelto;
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# /sys
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allow kernel sysfs:{ dir file lnk_file } relabelfrom;
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allow kernel sysfs_type:{ dir file lnk_file } relabelto;
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allow kernel sysfs_type:dir r_dir_perms;
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# Initial setenforce by init prior to switching to init domain.
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# We use dontaudit instead of allow to prevent a kernel spawned userspace
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# process from turning off SELinux once enabled.
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dontaudit kernel self:security setenforce;
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# Write to /proc/1/oom_adj prior to switching to init domain.
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allow kernel self:capability sys_resource;
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# Set checkreqprot by init.rc prior to switching to init domain.
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allow kernel selinuxfs:file write;
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allow kernel self:security setcheckreqprot;
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# MTP sync (b/15835289)
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# kernel thread "loop0", used by the loop block device, for ASECs (b/17158723)
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allow kernel sdcard_type:file { read write };
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###
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### neverallow rules
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###
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# The initial task starts in the kernel domain (assigned via
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# initial_sid_contexts), but nothing ever transitions to it.
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neverallow domain kernel:process { transition dyntransition };
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# The kernel domain is never entered via an exec, nor should it
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# ever execute a program outside the rootfs without changing to another domain.
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# If you encounter an execute_no_trans denial on the kernel domain, then
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# possible causes include:
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# - The program is a kernel usermodehelper. In this case, define a domain
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# for the program and domain_auto_trans() to it.
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# - You failed to setcon u:r:init:s0 in your init.rc and thus your init
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# program was left in the kernel domain and is now trying to execute
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# some other program. Fix your init.rc file.
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# - You are running an exploit which switched to the init task credentials
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# and is then trying to exec a shell or other program. You lose!
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neverallow kernel { file_type fs_type -rootfs }:file { entrypoint execute_no_trans };
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