-config SECURITY_SECLVL
- tristate "BSD Secure Levels"
- depends on SECURITY
- select CRYPTO
- select CRYPTO_SHA1
- help
- Implements BSD Secure Levels as an LSM. See
- <file:Documentation/seclvl.txt> for instructions on how to use this
- module.
+config SECURITY_DEFAULT_MMAP_MIN_ADDR
+ int "Low address space to protect from user allocation"
+ depends on SECURITY
+ default 0
+ help
+ This is the portion of low virtual memory which should be protected
+ from userspace allocation. Keeping a user from writing to low pages
+ can help reduce the impact of kernel NULL pointer bugs.
+
+ For most ia64, ppc64 and x86 users with lots of address space
+ a value of 65536 is reasonable and should cause no problems.
+ On arm and other archs it should not be higher than 32768.
+ Programs which use vm86 functionality would either need additional
+ permissions from either the LSM or the capabilities module or have
+ this protection disabled.
+
+ This value can be changed after boot using the
+ /proc/sys/vm/mmap_min_addr tunable.