diff options
| -rw-r--r-- | fs/proc/base.c | 3 | ||||
| -rw-r--r-- | init/Kconfig | 14 | ||||
| -rw-r--r-- | kernel/auditsc.c | 11 |
3 files changed, 24 insertions, 4 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index e3cbebbabebd..482df23036b5 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1197,9 +1197,6 @@ static ssize_t proc_loginuid_write(struct file * file, const char __user * buf, ssize_t length; uid_t loginuid; - if (!capable(CAP_AUDIT_CONTROL)) - return -EPERM; - rcu_read_lock(); if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) { rcu_read_unlock(); diff --git a/init/Kconfig b/init/Kconfig index a075765d5fbe..5ad8b775f2ac 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -372,6 +372,20 @@ config AUDIT_TREE depends on AUDITSYSCALL select FSNOTIFY +config AUDIT_LOGINUID_IMMUTABLE + bool "Make audit loginuid immutable" + depends on AUDIT + help + The config option toggles if a task setting it's loginuid requires + CAP_SYS_AUDITCONTROL or if that task should require no special permissions + but should instead only allow setting its loginuid if it was never + previously set. On systems which use systemd or a similar central + process to restart login services this should be set to true. On older + systems in which an admin would typically have to directly stop and + start processes this should be set to false. Setting this to true allows + one to drop potentially dangerous capabilites from the login tasks, + but may not be backwards compatible with older init systems. + source "kernel/irq/Kconfig" menu "RCU Subsystem" diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 9d6dd7d869c0..bd084a13c719 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -2173,9 +2173,18 @@ static atomic_t session_id = ATOMIC_INIT(0); int audit_set_loginuid(uid_t loginuid) { struct task_struct *task = current; - unsigned int sessionid = atomic_inc_return(&session_id); struct audit_context *context = task->audit_context; + unsigned int sessionid; + +#ifdef CONFIG_AUDIT_LOGINUID_IMMUTABLE + if (task->loginuid != -1) + return -EPERM; +#else /* CONFIG_AUDIT_LOGINUID_IMMUTABLE */ + if (!capable(CAP_AUDIT_CONTROL)) + return -EPERM; +#endif /* CONFIG_AUDIT_LOGINUID_IMMUTABLE */ + sessionid = atomic_inc_return(&session_id); if (context && context->in_syscall) { struct audit_buffer *ab; |