7028bdccd5
To help reduce code injection paths, a neverallow is placed to prevent domain, sans untrusted_app and shell, execute on data_file_type. A few data_file_type's are also exempt from this rule as they label files that should be executable. Additional constraints, on top of the above, are placed on domains system_server and zygote. They can only execute data_file_type's of type dalvikcache_data_file. Change-Id: I15dafbce80ba2c85a03c23128eae4725703d5f02 Signed-off-by: William Roberts <william.c.roberts@intel.com>
86 lines
3.6 KiB
Text
86 lines
3.6 KiB
Text
# zygote
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type zygote, domain;
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type zygote_exec, exec_type, file_type;
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init_daemon_domain(zygote)
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typeattribute zygote mlstrustedsubject;
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# Override DAC on files and switch uid/gid.
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allow zygote self:capability { dac_override setgid setuid fowner chown };
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# Drop capabilities from bounding set.
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allow zygote self:capability setpcap;
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# Switch SELinux context to app domains.
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allow zygote self:process setcurrent;
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allow zygote system_server:process dyntransition;
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allow zygote appdomain:process dyntransition;
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# Allow zygote to read app /proc/pid dirs (b/10455872)
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allow zygote appdomain:dir { getattr search };
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allow zygote appdomain:file { r_file_perms };
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# Move children into the peer process group.
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allow zygote system_server:process { getpgid setpgid };
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allow zygote appdomain:process { getpgid setpgid };
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# Read system data.
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allow zygote system_data_file:dir r_dir_perms;
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allow zygote system_data_file:file r_file_perms;
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# Write to /data/dalvik-cache.
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allow zygote dalvikcache_data_file:dir create_dir_perms;
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allow zygote dalvikcache_data_file:file create_file_perms;
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# Create symlinks in /data/dalvik-cache
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allow zygote dalvikcache_data_file:lnk_file create_file_perms;
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# Write to /data/resource-cache
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allow zygote resourcecache_data_file:dir rw_dir_perms;
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allow zygote resourcecache_data_file:file create_file_perms;
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# For art.
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allow zygote dalvikcache_data_file:file execute;
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# Execute idmap and dex2oat within zygote's own domain.
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# TODO: Should either of these be transitioned to the same domain
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# used by installd or stay in-domain for zygote?
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allow zygote idmap_exec:file rx_file_perms;
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allow zygote dex2oat_exec:file rx_file_perms;
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# Control cgroups.
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allow zygote cgroup:dir create_dir_perms;
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allow zygote self:capability sys_admin;
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# Check validity of SELinux context before use.
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selinux_check_context(zygote)
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# Check SELinux permissions.
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selinux_check_access(zygote)
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# Read /seapp_contexts and /data/security/seapp_contexts
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security_access_policy(zygote)
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# Native bridge functionality requires that zygote replaces
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# /proc/cpuinfo with /system/lib/<ISA>/cpuinfo using a bind mount
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allow zygote proc_cpuinfo:file mounton;
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# Allow remounting rootfs as MS_SLAVE
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allow zygote rootfs:dir mounton;
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allow zygote sdcard_type:dir { write search setattr create add_name mounton }; # TODO: deprecated in M
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dontaudit zygote self:capability fsetid; # TODO: deprecated in M
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allow zygote tmpfs:dir { write create add_name setattr mounton search }; # TODO: deprecated in M
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allow zygote tmpfs:filesystem mount; # TODO: deprecated in M
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allow zygote labeledfs:filesystem remount; # TODO: deprecated in M
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# Allowed to create user-specific storage source if started before vold
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allow zygote mnt_user_file:dir create_dir_perms;
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allow zygote mnt_user_file:lnk_file create_file_perms;
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# Allowed to mount user-specific storage into place
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allow zygote storage_file:dir { search mounton };
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# Handle --invoke-with command when launching Zygote with a wrapper command.
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allow zygote zygote_exec:file rx_file_perms;
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###
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### neverallow rules
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###
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# Ensure that all types assigned to app processes are included
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# in the appdomain attribute, so that all allow and neverallow rules
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# written on appdomain are applied to all app processes.
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# This is achieved by ensuring that it is impossible for zygote to
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# setcon (dyntransition) to any types other than those associated
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# with appdomain plus system_server.
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neverallow zygote ~{ appdomain system_server }:process dyntransition;
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# Zygote should never execute anything from /data except for /data/dalvik-cache files.
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neverallow zygote {
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data_file_type
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-dalvikcache_data_file # map PROT_EXEC
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}:file no_x_file_perms;
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