1kernel_selinux(8) SELinux Policy kernel kernel_selinux(8)
2
3
4
6 kernel_selinux - Security Enhanced Linux Policy for the kernel pro‐
7 cesses
8
10 Security-Enhanced Linux secures the kernel processes via flexible
11 mandatory access control.
12
13 The kernel processes execute with the kernel_t SELinux type. You can
14 check if you have these processes running by executing the ps command
15 with the -Z qualifier.
16
17 For example:
18
19 ps -eZ | grep kernel_t
20
21
22
24 SELinux defines process types (domains) for each process running on the
25 system
26
27 You can see the context of a process using the -Z option to ps
28
29 Policy governs the access confined processes have to files. SELinux
30 kernel policy is very flexible allowing users to setup their kernel
31 processes in as secure a method as possible.
32
33 The following process types are defined for kernel:
34
35 kernel_t
36
37 Note: semanage permissive -a kernel_t can be used to make the process
38 type kernel_t permissive. SELinux does not deny access to permissive
39 process types, but the AVC (SELinux denials) messages are still gener‐
40 ated.
41
42
44 SELinux policy is customizable based on least access required. kernel
45 policy is extremely flexible and has several booleans that allow you to
46 manipulate the policy and run kernel with the tightest access possible.
47
48
49
50 If you want to deny user domains applications to map a memory region as
51 both executable and writable, this is dangerous and the executable
52 should be reported in bugzilla, you must turn on the deny_execmem bool‐
53 ean. Enabled by default.
54
55 setsebool -P deny_execmem 1
56
57
58
59 If you want to allow all domains to execute in fips_mode, you must turn
60 on the fips_mode boolean. Enabled by default.
61
62 setsebool -P fips_mode 1
63
64
65
66 If you want to control the ability to mmap a low area of the address
67 space, as configured by /proc/sys/vm/mmap_min_addr, you must turn on
68 the mmap_low_allowed boolean. Disabled by default.
69
70 setsebool -P mmap_low_allowed 1
71
72
73
74 If you want to allow any files/directories to be exported read/only via
75 NFS, you must turn on the nfs_export_all_ro boolean. Enabled by
76 default.
77
78 setsebool -P nfs_export_all_ro 1
79
80
81
82 If you want to allow any files/directories to be exported read/write
83 via NFS, you must turn on the nfs_export_all_rw boolean. Enabled by
84 default.
85
86 setsebool -P nfs_export_all_rw 1
87
88
89
90 If you want to allow system to run with NIS, you must turn on the
91 nis_enabled boolean. Disabled by default.
92
93 setsebool -P nis_enabled 1
94
95
96
97 If you want to disable kernel module loading, you must turn on the
98 secure_mode_insmod boolean. Enabled by default.
99
100 setsebool -P secure_mode_insmod 1
101
102
103
104 If you want to allow unconfined executables to make their heap memory
105 executable. Doing this is a really bad idea. Probably indicates a
106 badly coded executable, but could indicate an attack. This executable
107 should be reported in bugzilla, you must turn on the selin‐
108 uxuser_execheap boolean. Disabled by default.
109
110 setsebool -P selinuxuser_execheap 1
111
112
113
114 If you want to allow unconfined executables to make their stack exe‐
115 cutable. This should never, ever be necessary. Probably indicates a
116 badly coded executable, but could indicate an attack. This executable
117 should be reported in bugzilla, you must turn on the selinuxuser_exec‐
118 stack boolean. Disabled by default.
119
120 setsebool -P selinuxuser_execstack 1
121
122
123
125 The SELinux process type kernel_t can manage files labeled with the
126 following file types. The paths listed are the default paths for these
127 file types. Note the processes UID still need to have DAC permissions.
128
129 file_type
130
131 all files on the system
132
133
135 semanage fcontext can also be used to manipulate default file context
136 mappings.
137
138 semanage permissive can also be used to manipulate whether or not a
139 process type is permissive.
140
141 semanage module can also be used to enable/disable/install/remove pol‐
142 icy modules.
143
144 semanage boolean can also be used to manipulate the booleans
145
146
147 system-config-selinux is a GUI tool available to customize SELinux pol‐
148 icy settings.
149
150
152 This manual page was auto-generated using sepolicy manpage .
153
154
156 selinux(8), kernel(8), semanage(8), restorecon(8), chcon(1), sepol‐
157 icy(8), setsebool(8)
158
159
160
161kernel 19-12-02 kernel_selinux(8)