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| author | Kees Cook <kees@ubuntu.com> | 2009-04-02 15:49:29 -0700 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2009-04-03 11:47:11 +1100 |
| commit | 3d43321b7015387cfebbe26436d0e9d299162ea1 (patch) | |
| tree | bae6bd123c8f573e844a7af11c96eb5f6a73e0ee /kernel/sysctl.c | |
| parent | 8a6f83afd0c5355db6d11394a798e94950306239 (diff) | |
| download | lwn-3d43321b7015387cfebbe26436d0e9d299162ea1.tar.gz lwn-3d43321b7015387cfebbe26436d0e9d299162ea1.zip | |
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 <kees.cook@canonical.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'kernel/sysctl.c')
| -rw-r--r-- | kernel/sysctl.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index c5ef44ff850f..2fb4246d27de 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -113,6 +113,7 @@ static int ngroups_max = NGROUPS_MAX; #ifdef CONFIG_MODULES extern char modprobe_path[]; +extern int modules_disabled; #endif #ifdef CONFIG_CHR_DEV_SG extern int sg_big_buff; @@ -533,6 +534,17 @@ static struct ctl_table kern_table[] = { .proc_handler = &proc_dostring, .strategy = &sysctl_string, }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "modules_disabled", + .data = &modules_disabled, + .maxlen = sizeof(int), + .mode = 0644, + /* only handle a transition from default "0" to "1" */ + .proc_handler = &proc_dointvec_minmax, + .extra1 = &one, + .extra2 = &one, + }, #endif #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET) { |