From 3d43321b7015387cfebbe26436d0e9d299162ea1 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 2 Apr 2009 15:49:29 -0700 Subject: modules: sysctl to block module loading Implement a sysctl file that disables module-loading system-wide since there is no longer a viable way to remove CAP_SYS_MODULE after the system bounding capability set was removed in 2.6.25. Value can only be set to "1", and is tested only if standard capability checks allow CAP_SYS_MODULE. Given existing /dev/mem protections, this should allow administrators a one-way method to block module loading after initial boot-time module loading has finished. Signed-off-by: Kees Cook Acked-by: Serge Hallyn Signed-off-by: James Morris --- Documentation/sysctl/kernel.txt | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'Documentation') diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index a4ccdd1981c..02b13495627 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -30,6 +30,7 @@ show up in /proc/sys/kernel: - kstack_depth_to_print [ X86 only ] - l2cr [ PPC only ] - modprobe ==> Documentation/debugging-modules.txt +- modules_disabled - msgmax - msgmnb - msgmni @@ -179,6 +180,16 @@ kernel stack. ============================================================== +modules_disabled: + +A toggle value indicating if modules are allowed to be loaded +in an otherwise modular kernel. This toggle defaults to off +(0), but can be set true (1). Once true, modules can be +neither loaded nor unloaded, and the toggle cannot be set back +to false. + +============================================================== + osrelease, ostype & version: # cat osrelease -- cgit v1.2.3-70-g09d2