1firstboot_selinux(8) SELinux Policy firstboot firstboot_selinux(8)
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6 firstboot_selinux - Security Enhanced Linux Policy for the firstboot
7 processes
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10 Security-Enhanced Linux secures the firstboot processes via flexible
11 mandatory access control.
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13 The firstboot processes execute with the firstboot_t SELinux type. You
14 can check if you have these processes running by executing the ps com‐
15 mand with the -Z qualifier.
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17 For example:
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19 ps -eZ | grep firstboot_t
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24 The firstboot_t SELinux type can be entered via the firstboot_exec_t
25 file type.
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27 The default entrypoint paths for the firstboot_t domain are the follow‐
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30 /usr/sbin/firstboot, /usr/share/firstboot/firstboot.py
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33 SELinux defines process types (domains) for each process running on the
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36 You can see the context of a process using the -Z option to ps
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38 Policy governs the access confined processes have to files. SELinux
39 firstboot policy is very flexible allowing users to setup their first‐
40 boot processes in as secure a method as possible.
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42 The following process types are defined for firstboot:
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44 firstboot_t
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46 Note: semanage permissive -a firstboot_t can be used to make the
47 process type firstboot_t permissive. SELinux does not deny access to
48 permissive process types, but the AVC (SELinux denials) messages are
49 still generated.
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53 SELinux policy is customizable based on least access required. first‐
54 boot policy is extremely flexible and has several booleans that allow
55 you to manipulate the policy and run firstboot with the tightest access
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60 If you want to allow all daemons the ability to read/write terminals,
61 you must turn on the daemons_use_tty boolean. Disabled by default.
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63 setsebool -P daemons_use_tty 1
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67 If you want to deny user domains applications to map a memory region as
68 both executable and writable, this is dangerous and the executable
69 should be reported in bugzilla, you must turn on the deny_execmem bool‐
70 ean. Enabled by default.
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72 setsebool -P deny_execmem 1
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76 If you want to deny any process from ptracing or debugging any other
77 processes, you must turn on the deny_ptrace boolean. Enabled by
78 default.
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80 setsebool -P deny_ptrace 1
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84 If you want to allow any process to mmap any file on system with
85 attribute file_type, you must turn on the domain_can_mmap_files bool‐
86 ean. Enabled by default.
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88 setsebool -P domain_can_mmap_files 1
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92 If you want to allow all domains write to kmsg_device, while kernel is
93 executed with systemd.log_target=kmsg parameter, you must turn on the
94 domain_can_write_kmsg boolean. Disabled by default.
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96 setsebool -P domain_can_write_kmsg 1
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100 If you want to allow all domains to use other domains file descriptors,
101 you must turn on the domain_fd_use boolean. Enabled by default.
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103 setsebool -P domain_fd_use 1
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107 If you want to allow all domains to have the kernel load modules, you
108 must turn on the domain_kernel_load_modules boolean. Disabled by
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111 setsebool -P domain_kernel_load_modules 1
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115 If you want to allow all domains to execute in fips_mode, you must turn
116 on the fips_mode boolean. Enabled by default.
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118 setsebool -P fips_mode 1
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122 If you want to enable reading of urandom for all domains, you must turn
123 on the global_ssp boolean. Disabled by default.
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125 setsebool -P global_ssp 1
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129 If you want to control the ability to mmap a low area of the address
130 space, as configured by /proc/sys/vm/mmap_min_addr, you must turn on
131 the mmap_low_allowed boolean. Disabled by default.
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133 setsebool -P mmap_low_allowed 1
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137 If you want to allow confined applications to use nscd shared memory,
138 you must turn on the nscd_use_shm boolean. Disabled by default.
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140 setsebool -P nscd_use_shm 1
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144 If you want to disable kernel module loading, you must turn on the
145 secure_mode_insmod boolean. Enabled by default.
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147 setsebool -P secure_mode_insmod 1
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151 If you want to boolean to determine whether the system permits loading
152 policy, setting enforcing mode, and changing boolean values. Set this
153 to true and you have to reboot to set it back, you must turn on the
154 secure_mode_policyload boolean. Enabled by default.
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156 setsebool -P secure_mode_policyload 1
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160 If you want to allow unconfined executables to make their heap memory
161 executable. Doing this is a really bad idea. Probably indicates a
162 badly coded executable, but could indicate an attack. This executable
163 should be reported in bugzilla, you must turn on the selin‐
164 uxuser_execheap boolean. Disabled by default.
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166 setsebool -P selinuxuser_execheap 1
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170 If you want to allow all unconfined executables to use libraries
171 requiring text relocation that are not labeled textrel_shlib_t, you
172 must turn on the selinuxuser_execmod boolean. Enabled by default.
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174 setsebool -P selinuxuser_execmod 1
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178 If you want to allow unconfined executables to make their stack exe‐
179 cutable. This should never, ever be necessary. Probably indicates a
180 badly coded executable, but could indicate an attack. This executable
181 should be reported in bugzilla, you must turn on the selinuxuser_exec‐
182 stack boolean. Enabled by default.
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184 setsebool -P selinuxuser_execstack 1
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188 If you want to support X userspace object manager, you must turn on the
189 xserver_object_manager boolean. Enabled by default.
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191 setsebool -P xserver_object_manager 1
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196 The SELinux process type firstboot_t can manage files labeled with the
197 following file types. The paths listed are the default paths for these
198 file types. Note the processes UID still need to have DAC permissions.
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200 file_type
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202 all files on the system
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206 SELinux requires files to have an extended attribute to define the file
207 type.
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209 You can see the context of a file using the -Z option to ls
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211 Policy governs the access confined processes have to these files.
212 SELinux firstboot policy is very flexible allowing users to setup their
213 firstboot processes in as secure a method as possible.
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215 STANDARD FILE CONTEXT
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217 SELinux defines the file context types for the firstboot, if you wanted
218 to store files with these types in a diffent paths, you need to execute
219 the semanage command to sepecify alternate labeling and then use
220 restorecon to put the labels on disk.
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222 semanage fcontext -a -t firstboot_etc_t '/srv/myfirstboot_con‐
223 tent(/.*)?'
224 restorecon -R -v /srv/myfirstboot_content
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226 Note: SELinux often uses regular expressions to specify labels that
227 match multiple files.
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229 The following file types are defined for firstboot:
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233 firstboot_etc_t
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235 - Set files with the firstboot_etc_t type, if you want to store first‐
236 boot files in the /etc directories.
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240 firstboot_exec_t
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242 - Set files with the firstboot_exec_t type, if you want to transition
243 an executable to the firstboot_t domain.
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246 Paths:
247 /usr/sbin/firstboot, /usr/share/firstboot/firstboot.py
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250 Note: File context can be temporarily modified with the chcon command.
251 If you want to permanently change the file context you need to use the
252 semanage fcontext command. This will modify the SELinux labeling data‐
253 base. You will need to use restorecon to apply the labels.
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257 semanage fcontext can also be used to manipulate default file context
258 mappings.
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260 semanage permissive can also be used to manipulate whether or not a
261 process type is permissive.
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263 semanage module can also be used to enable/disable/install/remove pol‐
264 icy modules.
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266 semanage boolean can also be used to manipulate the booleans
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269 system-config-selinux is a GUI tool available to customize SELinux pol‐
270 icy settings.
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274 This manual page was auto-generated using sepolicy manpage .
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278 selinux(8), firstboot(8), semanage(8), restorecon(8), chcon(1), sepol‐
279 icy(8) , setsebool(8)
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283firstboot 19-04-25 firstboot_selinux(8)