Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit

Pull audit updates from Paul Moore:
 "Seven audit patches for 4.5, all very minor despite the diffstat.

  The diffstat churn for linux/audit.h can be attributed to needing to
  reshuffle the linux/audit.h header to fix the seccomp auditing issue
  (see the commit description for details).

  Besides the seccomp/audit fix, most of the fixes are around trying to
  improve the connection with the audit daemon and a Kconfig
  simplification.  Nothing crazy, and everything passes our little
  audit-testsuite"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  audit: always enable syscall auditing when supported and audit is enabled
  audit: force seccomp event logging to honor the audit_enabled flag
  audit: Delete unnecessary checks before two function calls
  audit: wake up threads if queue switched from limited to unlimited
  audit: include auditd's threads in audit_log_start() wait exception
  audit: remove audit_backlog_wait_overflow
  audit: don't needlessly reset valid wait time

3 files changed, 114 insertions, 118 deletions

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 20eba1eb0a3c..476bc1237ec2 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -113,6 +113,107 @@ struct filename;
 
 extern void audit_log_session_info(struct audit_buffer *ab);
 
+#ifdef CONFIG_AUDIT
+/* These are defined in audit.c */
+                                /* Public API */
+extern __printf(4, 5)
+void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
+               const char *fmt, ...);
+
+extern struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type);
+extern __printf(2, 3)
+void audit_log_format(struct audit_buffer *ab, const char *fmt, ...);
+extern void                 audit_log_end(struct audit_buffer *ab);
+extern bool                 audit_string_contains_control(const char *string,
+                                                          size_t len);
+extern void                 audit_log_n_hex(struct audit_buffer *ab,
+                                          const unsigned char *buf,
+                                          size_t len);
+extern void                 audit_log_n_string(struct audit_buffer *ab,
+                                               const char *buf,
+                                               size_t n);
+extern void                 audit_log_n_untrustedstring(struct audit_buffer *ab,
+                                                        const char *string,
+                                                        size_t n);
+extern void                 audit_log_untrustedstring(struct audit_buffer *ab,
+                                                      const char *string);
+extern void                 audit_log_d_path(struct audit_buffer *ab,
+                                             const char *prefix,
+                                             const struct path *path);
+extern void                 audit_log_key(struct audit_buffer *ab,
+                                          char *key);
+extern void                 audit_log_link_denied(const char *operation,
+                                                  struct path *link);
+extern void                 audit_log_lost(const char *message);
+#ifdef CONFIG_SECURITY
+extern void                 audit_log_secctx(struct audit_buffer *ab, u32 secid);
+#else
+static inline void          audit_log_secctx(struct audit_buffer *ab, u32 secid)
+{ }
+#endif
+
+extern int audit_log_task_context(struct audit_buffer *ab);
+extern void audit_log_task_info(struct audit_buffer *ab,
+                                struct task_struct *tsk);
+
+extern int                  audit_update_lsm_rules(void);
+
+                                /* Private API (for audit.c only) */
+extern int audit_filter_user(int type);
+extern int audit_filter_type(int type);
+extern int audit_rule_change(int type, __u32 portid, int seq,
+                                void *data, size_t datasz);
+extern int audit_list_rules_send(struct sk_buff *request_skb, int seq);
+
+extern u32 audit_enabled;
+#else /* CONFIG_AUDIT */
+static inline __printf(4, 5)
+void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
+               const char *fmt, ...)
+{ }
+static inline struct audit_buffer *audit_log_start(struct audit_context *ctx,
+                                                   gfp_t gfp_mask, int type)
+{
+        return NULL;
+}
+static inline __printf(2, 3)
+void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
+{ }
+static inline void audit_log_end(struct audit_buffer *ab)
+{ }
+static inline void audit_log_n_hex(struct audit_buffer *ab,
+                                   const unsigned char *buf, size_t len)
+{ }
+static inline void audit_log_n_string(struct audit_buffer *ab,
+                                      const char *buf, size_t n)
+{ }
+static inline void  audit_log_n_untrustedstring(struct audit_buffer *ab,
+                                                const char *string, size_t n)
+{ }
+static inline void audit_log_untrustedstring(struct audit_buffer *ab,
+                                             const char *string)
+{ }
+static inline void audit_log_d_path(struct audit_buffer *ab,
+                                    const char *prefix,
+                                    const struct path *path)
+{ }
+static inline void audit_log_key(struct audit_buffer *ab, char *key)
+{ }
+static inline void audit_log_link_denied(const char *string,
+                                         const struct path *link)
+{ }
+static inline void audit_log_secctx(struct audit_buffer *ab, u32 secid)
+{ }
+static inline int audit_log_task_context(struct audit_buffer *ab)
+{
+        return 0;
+}
+static inline void audit_log_task_info(struct audit_buffer *ab,
+                                       struct task_struct *tsk)
+{ }
+#define audit_enabled 0
+#endif /* CONFIG_AUDIT */
+
 #ifdef CONFIG_AUDIT_COMPAT_GENERIC
 #define audit_is_compat(arch)  (!((arch) & __AUDIT_ARCH_64BIT))
 #else
@@ -212,6 +313,9 @@ void audit_core_dumps(long signr);
 
 static inline void audit_seccomp(unsigned long syscall, long signr, int code)
 {
+        if (!audit_enabled)
+                return;
+
         /* Force a record to be reported if a signal was delivered. */
         if (signr || unlikely(!audit_dummy_context()))
                 __audit_seccomp(syscall, signr, code);
@@ -446,106 +550,6 @@ static inline bool audit_loginuid_set(struct task_struct *tsk)
         return uid_valid(audit_get_loginuid(tsk));
 }
 
-#ifdef CONFIG_AUDIT
-/* These are defined in audit.c */
-                                /* Public API */
-extern __printf(4, 5)
-void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
-               const char *fmt, ...);
-
-extern struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type);
-extern __printf(2, 3)
-void audit_log_format(struct audit_buffer *ab, const char *fmt, ...);
-extern void                 audit_log_end(struct audit_buffer *ab);
-extern bool                 audit_string_contains_control(const char *string,
-                                                          size_t len);
-extern void                 audit_log_n_hex(struct audit_buffer *ab,
-                                          const unsigned char *buf,
-                                          size_t len);
-extern void                 audit_log_n_string(struct audit_buffer *ab,
-                                               const char *buf,
-                                               size_t n);
-extern void                 audit_log_n_untrustedstring(struct audit_buffer *ab,
-                                                        const char *string,
-                                                        size_t n);
-extern void                 audit_log_untrustedstring(struct audit_buffer *ab,
-                                                      const char *string);
-extern void                 audit_log_d_path(struct audit_buffer *ab,
-                                             const char *prefix,
-                                             const struct path *path);
-extern void                 audit_log_key(struct audit_buffer *ab,
-                                          char *key);
-extern void                 audit_log_link_denied(const char *operation,
-                                                  struct path *link);
-extern void                 audit_log_lost(const char *message);
-#ifdef CONFIG_SECURITY
-extern void                 audit_log_secctx(struct audit_buffer *ab, u32 secid);
-#else
-static inline void          audit_log_secctx(struct audit_buffer *ab, u32 secid)
-{ }
-#endif
-
-extern int audit_log_task_context(struct audit_buffer *ab);
-extern void audit_log_task_info(struct audit_buffer *ab,
-                                struct task_struct *tsk);
-
-extern int                  audit_update_lsm_rules(void);
-
-                                /* Private API (for audit.c only) */
-extern int audit_filter_user(int type);
-extern int audit_filter_type(int type);
-extern int audit_rule_change(int type, __u32 portid, int seq,
-                                void *data, size_t datasz);
-extern int audit_list_rules_send(struct sk_buff *request_skb, int seq);
-
-extern u32 audit_enabled;
-#else /* CONFIG_AUDIT */
-static inline __printf(4, 5)
-void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
-               const char *fmt, ...)
-{ }
-static inline struct audit_buffer *audit_log_start(struct audit_context *ctx,
-                                                   gfp_t gfp_mask, int type)
-{
-        return NULL;
-}
-static inline __printf(2, 3)
-void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
-{ }
-static inline void audit_log_end(struct audit_buffer *ab)
-{ }
-static inline void audit_log_n_hex(struct audit_buffer *ab,
-                                   const unsigned char *buf, size_t len)
-{ }
-static inline void audit_log_n_string(struct audit_buffer *ab,
-                                      const char *buf, size_t n)
-{ }
-static inline void  audit_log_n_untrustedstring(struct audit_buffer *ab,
-                                                const char *string, size_t n)
-{ }
-static inline void audit_log_untrustedstring(struct audit_buffer *ab,
-                                             const char *string)
-{ }
-static inline void audit_log_d_path(struct audit_buffer *ab,
-                                    const char *prefix,
-                                    const struct path *path)
-{ }
-static inline void audit_log_key(struct audit_buffer *ab, char *key)
-{ }
-static inline void audit_log_link_denied(const char *string,
-                                         const struct path *link)
-{ }
-static inline void audit_log_secctx(struct audit_buffer *ab, u32 secid)
-{ }
-static inline int audit_log_task_context(struct audit_buffer *ab)
-{
-        return 0;
-}
-static inline void audit_log_task_info(struct audit_buffer *ab,
-                                       struct task_struct *tsk)
-{ }
-#define audit_enabled 0
-#endif /* CONFIG_AUDIT */
 static inline void audit_log_string(struct audit_buffer *ab, const char *buf)
 {
         audit_log_n_string(ab, buf, strlen(buf));
diff --git a/init/Kconfig b/init/Kconfig
index 4644217b2373..5b86082fa238 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -299,20 +299,15 @@ config AUDIT
         help
           Enable auditing infrastructure that can be used with another
           kernel subsystem, such as SELinux (which requires this for
-          logging of avc messages output).  Does not do system-call
-          auditing without CONFIG_AUDITSYSCALL.
+          logging of avc messages output).  System call auditing is included
+          on architectures which support it.
 
 config HAVE_ARCH_AUDITSYSCALL
         bool
 
 config AUDITSYSCALL
-        bool "Enable system-call auditing support"
+        def_bool y
         depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
-        default y if SECURITY_SELINUX
-        help
-          Enable low-overhead system-call auditing infrastructure that
-          can be used independently or with another kernel subsystem,
-          such as SELinux.
 
 config AUDIT_WATCH
         def_bool y
diff --git a/kernel/audit.c b/kernel/audit.c
index 5ffcbd354a52..d6dd95cc59e6 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -110,7 +110,6 @@ static u32	audit_backlog_limit = 64;
 #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
 static u32      audit_backlog_wait_time_master = AUDIT_BACKLOG_WAIT_TIME;
 static u32      audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
-static u32      audit_backlog_wait_overflow = 0;
 
 /* The identity of the user shutting down the audit system. */
 kuid_t          audit_sig_uid = INVALID_UID;
@@ -509,8 +508,7 @@ static void flush_hold_queue(void)
          * if auditd just disappeared but we
          * dequeued an skb we need to drop ref
          */
-        if (skb)
-                consume_skb(skb);
+        consume_skb(skb);
 }
 
 static int kauditd_thread(void *dummy)
@@ -524,7 +522,8 @@ static int kauditd_thread(void *dummy)
                 skb = skb_dequeue(&audit_skb_queue);
 
                 if (skb) {
-                        if (skb_queue_len(&audit_skb_queue) <= audit_backlog_limit)
+                        if (!audit_backlog_limit ||
+                            (skb_queue_len(&audit_skb_queue) <= audit_backlog_limit))
                                 wake_up(&audit_backlog_wait);
                         if (audit_pid)
                                 kauditd_send_skb(skb);
@@ -1232,9 +1231,7 @@ static void audit_buffer_free(struct audit_buffer *ab)
         if (!ab)
                 return;
 
-        if (ab->skb)
-                kfree_skb(ab->skb);
-
+        kfree_skb(ab->skb);
         spin_lock_irqsave(&audit_freelist_lock, flags);
         if (audit_freelist_count > AUDIT_MAXFREE)
                 kfree(ab);
@@ -1372,7 +1369,7 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
                 return NULL;
 
         if (gfp_mask & __GFP_DIRECT_RECLAIM) {
-                if (audit_pid && audit_pid == current->pid)
+                if (audit_pid && audit_pid == current->tgid)
                         gfp_mask &= ~__GFP_DIRECT_RECLAIM;
                 else
                         reserve = 0;
@@ -1395,12 +1392,12 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
                                 skb_queue_len(&audit_skb_queue),
                                 audit_backlog_limit);
                 audit_log_lost("backlog limit exceeded");
-                audit_backlog_wait_time = audit_backlog_wait_overflow;
+                audit_backlog_wait_time = 0;
                 wake_up(&audit_backlog_wait);
                 return NULL;
         }
 
-        if (!reserve)
+        if (!reserve && !audit_backlog_wait_time)
                 audit_backlog_wait_time = audit_backlog_wait_time_master;
 
         ab = audit_buffer_alloc(ctx, gfp_mask, type);