|author||Eric Paris <firstname.lastname@example.org>||2009-07-31 12:54:11 -0400|
|committer||James Morris <email@example.com>||2009-08-17 15:09:11 +1000|
Security/SELinux: seperate lsm specific mmap_min_addr
Currently SELinux enforcement of controls on the ability to map low memory is determined by the mmap_min_addr tunable. This patch causes SELinux to ignore the tunable and instead use a seperate Kconfig option specific to how much space the LSM should protect. The tunable will now only control the need for CAP_SYS_RAWIO and SELinux permissions will always protect the amount of low memory designated by CONFIG_LSM_MMAP_MIN_ADDR. This allows users who need to disable the mmap_min_addr controls (usual reason being they run WINE as a non-root user) to do so and still have SELinux controls preventing confined domains (like a web server) from being able to map some area of low memory. Signed-off-by: Eric Paris <firstname.lastname@example.org> Signed-off-by: James Morris <email@example.com>
Diffstat (limited to 'security/Kconfig')
1 files changed, 16 insertions, 0 deletions
diff --git a/security/Kconfig b/security/Kconfig
index d23c839038f0..9c60c346a91d 100644
@@ -113,6 +113,22 @@ config SECURITY_ROOTPLUG
If you are unsure how to answer this question, answer N.
+ int "Low address space for LSM to from user allocation"
+ depends on SECURITY && SECURITY_SELINUX
+ default 65535
+ 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 or have some need to map
+ this low address space will need the permission specific to the
+ systems running LSM.