From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Jeremy Cline Date: Mon, 30 Sep 2019 21:22:47 +0000 Subject: [PATCH] security: lockdown: expose a hook to lock the kernel down In order to automatically lock down kernels running on UEFI machines booted in Secure Boot mode, expose the lock_kernel_down() hook. Upstream Status: RHEL only Signed-off-by: Jeremy Cline --- include/linux/lsm_hook_defs.h | 2 ++ include/linux/lsm_hooks.h | 6 ++++++ include/linux/security.h | 5 +++++ security/lockdown/lockdown.c | 1 + security/security.c | 6 ++++++ 5 files changed, 20 insertions(+) diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 5616b2567aa7..bc5caab1413b 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -371,6 +371,8 @@ LSM_HOOK(void, LSM_RET_VOID, bpf_prog_free_security, struct bpf_prog_aux *aux) #endif /* CONFIG_BPF_SYSCALL */ LSM_HOOK(int, 0, locked_down, enum lockdown_reason what) +LSM_HOOK(int, 0, lock_kernel_down, const char *where, enum lockdown_reason level) + #ifdef CONFIG_PERF_EVENTS LSM_HOOK(int, 0, perf_event_open, struct perf_event_attr *attr, int type) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 988ca0df7824..4ed37b95417c 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1476,6 +1476,12 @@ * * @what: kernel feature being accessed * + * @lock_kernel_down + * Put the kernel into lock-down mode. + * + * @where: Where the lock-down is originating from (e.g. command line option) + * @level: The lock-down level (can only increase) + * * Security hooks for perf events * * @perf_event_open: diff --git a/include/linux/security.h b/include/linux/security.h index a8d9310472df..381305889d89 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -446,6 +446,7 @@ int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen); int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen); int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen); int security_locked_down(enum lockdown_reason what); +int security_lock_kernel_down(const char *where, enum lockdown_reason level); #else /* CONFIG_SECURITY */ static inline int call_blocking_lsm_notifier(enum lsm_event event, void *data) @@ -1273,6 +1274,10 @@ static inline int security_locked_down(enum lockdown_reason what) { return 0; } +static inline int security_lock_kernel_down(const char *where, enum lockdown_reason level) +{ + return 0; +} #endif /* CONFIG_SECURITY */ #ifdef CONFIG_SECURITY_NETWORK diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c index 5a952617a0eb..61cc3cdc4d25 100644 --- a/security/lockdown/lockdown.c +++ b/security/lockdown/lockdown.c @@ -73,6 +73,7 @@ static int lockdown_is_locked_down(enum lockdown_reason what) static struct security_hook_list lockdown_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(locked_down, lockdown_is_locked_down), + LSM_HOOK_INIT(lock_kernel_down, lock_kernel_down), }; static int __init lockdown_lsm_init(void) diff --git a/security/security.c b/security/security.c index 51de970fbb1e..48d05f8067f2 100644 --- a/security/security.c +++ b/security/security.c @@ -2468,6 +2468,12 @@ int security_locked_down(enum lockdown_reason what) } EXPORT_SYMBOL(security_locked_down); +int security_lock_kernel_down(const char *where, enum lockdown_reason level) +{ + return call_int_hook(lock_kernel_down, 0, where, level); +} +EXPORT_SYMBOL(security_lock_kernel_down); + #ifdef CONFIG_PERF_EVENTS int security_perf_event_open(struct perf_event_attr *attr, int type) { -- 2.26.2