mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-16 00:34:20 +08:00
e9c38f9fc2
Deprecate setting the SELinux checkreqprot tunable to 1 via kernel
parameter or /sys/fs/selinux/checkreqprot. Setting it to 0 is left
intact for compatibility since Android and some Linux distributions
do so for security and treat an inability to set it as a fatal error.
Eventually setting it to 0 will become a no-op and the kernel will
stop using checkreqprot's value internally altogether.
checkreqprot was originally introduced as a compatibility mechanism
for legacy userspace and the READ_IMPLIES_EXEC personality flag.
However, if set to 1, it weakens security by allowing mappings to be
made executable without authorization by policy. The default value
for the SECURITY_SELINUX_CHECKREQPROT_VALUE config option was changed
from 1 to 0 in commit 2a35d196c1 ("selinux: change
CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default") and both Android
and Linux distributions began explicitly setting
/sys/fs/selinux/checkreqprot to 0 some time ago.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
118 lines
4.5 KiB
Plaintext
118 lines
4.5 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
|
|
config SECURITY_SELINUX
|
|
bool "NSA SELinux Support"
|
|
depends on SECURITY_NETWORK && AUDIT && NET && INET
|
|
select NETWORK_SECMARK
|
|
default n
|
|
help
|
|
This selects NSA Security-Enhanced Linux (SELinux).
|
|
You will also need a policy configuration and a labeled filesystem.
|
|
If you are unsure how to answer this question, answer N.
|
|
|
|
config SECURITY_SELINUX_BOOTPARAM
|
|
bool "NSA SELinux boot parameter"
|
|
depends on SECURITY_SELINUX
|
|
default n
|
|
help
|
|
This option adds a kernel parameter 'selinux', which allows SELinux
|
|
to be disabled at boot. If this option is selected, SELinux
|
|
functionality can be disabled with selinux=0 on the kernel
|
|
command line. The purpose of this option is to allow a single
|
|
kernel image to be distributed with SELinux built in, but not
|
|
necessarily enabled.
|
|
|
|
If you are unsure how to answer this question, answer N.
|
|
|
|
config SECURITY_SELINUX_DISABLE
|
|
bool "NSA SELinux runtime disable"
|
|
depends on SECURITY_SELINUX
|
|
select SECURITY_WRITABLE_HOOKS
|
|
default n
|
|
help
|
|
This option enables writing to a selinuxfs node 'disable', which
|
|
allows SELinux to be disabled at runtime prior to the policy load.
|
|
SELinux will then remain disabled until the next boot.
|
|
This option is similar to the selinux=0 boot parameter, but is to
|
|
support runtime disabling of SELinux, e.g. from /sbin/init, for
|
|
portability across platforms where boot parameters are difficult
|
|
to employ.
|
|
|
|
NOTE: selecting this option will disable the '__ro_after_init'
|
|
kernel hardening feature for security hooks. Please consider
|
|
using the selinux=0 boot parameter instead of enabling this
|
|
option.
|
|
|
|
WARNING: this option is deprecated and will be removed in a future
|
|
kernel release.
|
|
|
|
If you are unsure how to answer this question, answer N.
|
|
|
|
config SECURITY_SELINUX_DEVELOP
|
|
bool "NSA SELinux Development Support"
|
|
depends on SECURITY_SELINUX
|
|
default y
|
|
help
|
|
This enables the development support option of NSA SELinux,
|
|
which is useful for experimenting with SELinux and developing
|
|
policies. If unsure, say Y. With this option enabled, the
|
|
kernel will start in permissive mode (log everything, deny nothing)
|
|
unless you specify enforcing=1 on the kernel command line. You
|
|
can interactively toggle the kernel between enforcing mode and
|
|
permissive mode (if permitted by the policy) via
|
|
/sys/fs/selinux/enforce.
|
|
|
|
config SECURITY_SELINUX_AVC_STATS
|
|
bool "NSA SELinux AVC Statistics"
|
|
depends on SECURITY_SELINUX
|
|
default y
|
|
help
|
|
This option collects access vector cache statistics to
|
|
/sys/fs/selinux/avc/cache_stats, which may be monitored via
|
|
tools such as avcstat.
|
|
|
|
config SECURITY_SELINUX_CHECKREQPROT_VALUE
|
|
int "NSA SELinux checkreqprot default value"
|
|
depends on SECURITY_SELINUX
|
|
range 0 1
|
|
default 0
|
|
help
|
|
This option sets the default value for the 'checkreqprot' flag
|
|
that determines whether SELinux checks the protection requested
|
|
by the application or the protection that will be applied by the
|
|
kernel (including any implied execute for read-implies-exec) for
|
|
mmap and mprotect calls. If this option is set to 0 (zero),
|
|
SELinux will default to checking the protection that will be applied
|
|
by the kernel. If this option is set to 1 (one), SELinux will
|
|
default to checking the protection requested by the application.
|
|
The checkreqprot flag may be changed from the default via the
|
|
'checkreqprot=' boot parameter. It may also be changed at runtime
|
|
via /sys/fs/selinux/checkreqprot if authorized by policy.
|
|
|
|
WARNING: this option is deprecated and will be removed in a future
|
|
kernel release.
|
|
|
|
If you are unsure how to answer this question, answer 0.
|
|
|
|
config SECURITY_SELINUX_SIDTAB_HASH_BITS
|
|
int "NSA SELinux sidtab hashtable size"
|
|
depends on SECURITY_SELINUX
|
|
range 8 13
|
|
default 9
|
|
help
|
|
This option sets the number of buckets used in the sidtab hashtable
|
|
to 2^SECURITY_SELINUX_SIDTAB_HASH_BITS buckets. The number of hash
|
|
collisions may be viewed at /sys/fs/selinux/ss/sidtab_hash_stats. If
|
|
chain lengths are high (e.g. > 20) then selecting a higher value here
|
|
will ensure that lookups times are short and stable.
|
|
|
|
config SECURITY_SELINUX_SID2STR_CACHE_SIZE
|
|
int "NSA SELinux SID to context string translation cache size"
|
|
depends on SECURITY_SELINUX
|
|
default 256
|
|
help
|
|
This option defines the size of the internal SID -> context string
|
|
cache, which improves the performance of context to string
|
|
conversion. Setting this option to 0 disables the cache completely.
|
|
|
|
If unsure, keep the default value.
|