1bootloader_selinux(8) SELinux Policy bootloader bootloader_selinux(8)
2
6 bootloader_selinux - Security Enhanced Linux Policy for the bootloader
7 processes
8
10 Security-Enhanced Linux secures the bootloader processes via flexible
11 mandatory access control.
12 The bootloader processes execute with the bootloader_t SELinux type.
14 You can check if you have these processes running by executing the ps
15 command with the -Z qualifier.
16 For example:
18 ps -eZ | grep bootloader_t
20
24 The bootloader_t SELinux type can be entered via the bootloader_exec_t
25 file type.
26 The default entrypoint paths for the bootloader_t domain are the fol‐
28 lowing:
29 /sbin/grub.*, /sbin/lilo.*, /sbin/ybin.*, /usr/sbin/grub.*,
31 /usr/sbin/lilo.*, /usr/sbin/ybin.*, /sbin/zipl, /usr/sbin/zipl
32
34 SELinux defines process types (domains) for each process running on the
35 system
36 You can see the context of a process using the -Z option to ps
38 Policy governs the access confined processes have to files. SELinux
40 bootloader policy is very flexible allowing users to setup their boot‐
41 loader processes in as secure a method as possible.
42 The following process types are defined for bootloader:
44 bootloader_t
46 Note: semanage permissive -a bootloader_t can be used to make the
48 process type bootloader_t permissive. SELinux does not deny access to
49 permissive process types, but the AVC (SELinux denials) messages are
50 still generated.
51
54 SELinux policy is customizable based on least access required. boot‐
55 loader policy is extremely flexible and has several booleans that allow
56 you to manipulate the policy and run bootloader with the tightest ac‐
57 cess possible.
58 If you want to control the ability to mmap a low area of the address
62 space, as configured by /proc/sys/vm/mmap_min_addr, you must turn on
63 the mmap_low_allowed boolean. Disabled by default.
64 setsebool -P mmap_low_allowed 1
66 If you want to disable kernel module loading, you must turn on the se‐
70 cure_mode_insmod boolean. Enabled by default.
71 setsebool -P secure_mode_insmod 1
73 If you want to allow unconfined executables to make their heap memory
77 executable. Doing this is a really bad idea. Probably indicates a
78 badly coded executable, but could indicate an attack. This executable
79 should be reported in bugzilla, you must turn on the selinuxuser_ex‐
80 echeap boolean. Disabled by default.
81 setsebool -P selinuxuser_execheap 1
83 If you want to allow unconfined executables to make their stack exe‐
87 cutable. This should never, ever be necessary. Probably indicates a
88 badly coded executable, but could indicate an attack. This executable
89 should be reported in bugzilla, you must turn on the selinuxuser_exec‐
90 stack boolean. Enabled by default.
91 setsebool -P selinuxuser_execstack 1
93
97 The SELinux process type bootloader_t can manage files labeled with the
98 following file types. The paths listed are the default paths for these
99 file types. Note the processes UID still need to have DAC permissions.
100 file_type
102 all files on the system
104
107 SELinux requires files to have an extended attribute to define the file
108 type.
109 You can see the context of a file using the -Z option to ls
111 Policy governs the access confined processes have to these files.
113 SELinux bootloader policy is very flexible allowing users to setup
114 their bootloader processes in as secure a method as possible.
115 STANDARD FILE CONTEXT
117 SELinux defines the file context types for the bootloader, if you
119 wanted to store files with these types in a diffent paths, you need to
120 execute the semanage command to specify alternate labeling and then use
121 restorecon to put the labels on disk.
122 semanage fcontext -a -t bootloader_tmp_t '/srv/mybootloader_con‐
124 tent(/.*)?'
125 restorecon -R -v /srv/mybootloader_content
126 Note: SELinux often uses regular expressions to specify labels that
128 match multiple files.
129 The following file types are defined for bootloader:
131 bootloader_etc_t
135 - Set files with the bootloader_etc_t type, if you want to store boot‐
137 loader files in the /etc directories.
138 Paths:
141 /etc/lilo.conf.*, /etc/zipl.conf.*, /etc/yaboot.conf.*, /etc/de‐
142 fault/grub
143 bootloader_exec_t
146 - Set files with the bootloader_exec_t type, if you want to transition
148 an executable to the bootloader_t domain.
149 Paths:
152 /sbin/grub.*, /sbin/lilo.*, /sbin/ybin.*, /usr/sbin/grub.*,
153 /usr/sbin/lilo.*, /usr/sbin/ybin.*, /sbin/zipl, /usr/sbin/zipl
154 bootloader_tmp_t
157 - Set files with the bootloader_tmp_t type, if you want to store boot‐
159 loader temporary files in the /tmp directories.
160 bootloader_var_lib_t
164 - Set files with the bootloader_var_lib_t type, if you want to store
166 the bootloader files under the /var/lib directory.
167 bootloader_var_run_t
171 - Set files with the bootloader_var_run_t type, if you want to store
173 the bootloader files under the /run or /var/run directory.
174 Note: File context can be temporarily modified with the chcon command.
178 If you want to permanently change the file context you need to use the
179 semanage fcontext command. This will modify the SELinux labeling data‐
180 base. You will need to use restorecon to apply the labels.
181
184 semanage fcontext can also be used to manipulate default file context
185 mappings.
186 semanage permissive can also be used to manipulate whether or not a
188 process type is permissive.
189 semanage module can also be used to enable/disable/install/remove pol‐
191 icy modules.
192 semanage boolean can also be used to manipulate the booleans
194 system-config-selinux is a GUI tool available to customize SELinux pol‐
197 icy settings.
198
201 This manual page was auto-generated using sepolicy manpage .
202
205 selinux(8), bootloader(8), semanage(8), restorecon(8), chcon(1), sepol‐
206 icy(8), setsebool(8)
207bootloader 22-05-27 bootloader_selinux(8)