sanitize audit_ipc_set_perm()

* get rid of allocations
* make it return void
* simplify callers

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

3 files changed, 32 insertions, 45 deletions

diff --git a/include/linux/audit.h b/include/linux/audit.h
index f8578b9088e1..b7abfe0d6737 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -444,7 +444,7 @@ extern int  audit_set_loginuid(struct task_struct *task, uid_t loginuid);
 #define audit_get_sessionid(t) ((t)->sessionid)
 extern void audit_log_task_context(struct audit_buffer *ab);
 extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
-extern int __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode);
+extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode);
 extern int audit_bprm(struct linux_binprm *bprm);
 extern void audit_socketcall(int nargs, unsigned long *args);
 extern int audit_sockaddr(int len, void *addr);
@@ -471,11 +471,10 @@ static inline int audit_fd_pair(int fd1, int fd2)
                 return __audit_fd_pair(fd1, fd2);
         return 0;
 }
-static inline int audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
+static inline void audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
 {
         if (unlikely(!audit_dummy_context()))
-                return __audit_ipc_set_perm(qbytes, uid, gid, mode);
-        return 0;
+                __audit_ipc_set_perm(qbytes, uid, gid, mode);
 }
 static inline int audit_mq_open(int oflag, mode_t mode, struct mq_attr __user *u_attr)
 {
@@ -546,7 +545,7 @@ extern int audit_signals;
 #define audit_get_sessionid(t) (-1)
 #define audit_log_task_context(b) do { ; } while (0)
 #define audit_ipc_obj(i) ((void)0)
-#define audit_ipc_set_perm(q,u,g,m) ({ 0; })
+#define audit_ipc_set_perm(q,u,g,m) ((void)0)
 #define audit_bprm(p) ({ 0; })
 #define audit_socketcall(n,a) ((void)0)
 #define audit_fd_pair(n,a) ({ 0; })
diff --git a/ipc/util.c b/ipc/util.c
index 579552abd50a..7585a72e259b 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -803,13 +803,9 @@ struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd,
         }
 
         audit_ipc_obj(ipcp);
-
-        if (cmd == IPC_SET) {
-                err = audit_ipc_set_perm(extra_perm, perm->uid,
+        if (cmd == IPC_SET)
+                audit_ipc_set_perm(extra_perm, perm->uid,
                                          perm->gid, perm->mode);
-                if (err)
-                        goto out_unlock;
-        }
 
         euid = current_euid();
         if (euid == ipcp->cuid ||
@@ -817,7 +813,6 @@ struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd,
                 return ipcp;
 
         err = -EPERM;
-out_unlock:
         ipc_unlock(ipcp);
 out_up:
         up_write(&ids->rw_mutex);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 73504313264f..fbed62e05bce 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -151,16 +151,6 @@ struct audit_aux_data_mq_getsetattr {
         struct mq_attr          mqstat;
 };
 
-struct audit_aux_data_ipcctl {
-        struct audit_aux_data   d;
-        struct ipc_perm         p;
-        unsigned long           qbytes;
-        uid_t                   uid;
-        gid_t                   gid;
-        mode_t                  mode;
-        u32                     osid;
-};
-
 struct audit_aux_data_execve {
         struct audit_aux_data   d;
         int argc;
@@ -252,6 +242,11 @@ struct audit_context {
                         gid_t                   gid;
                         mode_t                  mode;
                         u32                     osid;
+                        int                     has_perm;
+                        uid_t                   perm_uid;
+                        gid_t                   perm_gid;
+                        mode_t                  perm_mode;
+                        unsigned long           qbytes;
                 } ipc;
         };
 
@@ -1260,6 +1255,19 @@ static void show_special(struct audit_context *context, int *call_panic)
                                 security_release_secctx(ctx, len);
                         }
                 }
+                if (context->ipc.has_perm) {
+                        audit_log_end(ab);
+                        ab = audit_log_start(context, GFP_KERNEL,
+                                             AUDIT_IPC_SET_PERM);
+                        audit_log_format(ab,
+                                "qbytes=%lx ouid=%u ogid=%u mode=%#o",
+                                context->ipc.qbytes,
+                                context->ipc.perm_uid,
+                                context->ipc.perm_gid,
+                                context->ipc.perm_mode);
+                        if (!ab)
+                                return;
+                }
                 break; }
         }
         audit_log_end(ab);
@@ -1379,13 +1387,6 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
                                 axi->mqstat.mq_msgsize, axi->mqstat.mq_curmsgs);
                         break; }
 
-                case AUDIT_IPC_SET_PERM: {
-                        struct audit_aux_data_ipcctl *axi = (void *)aux;
-                        audit_log_format(ab,
-                                "qbytes=%lx ouid=%u ogid=%u mode=%#o",
-                                axi->qbytes, axi->uid, axi->gid, axi->mode);
-                        break; }
-
                 case AUDIT_EXECVE: {
                         struct audit_aux_data_execve *axi = (void *)aux;
                         audit_log_execve_info(context, &ab, axi);
@@ -2352,6 +2353,7 @@ void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
         context->ipc.uid = ipcp->uid;
         context->ipc.gid = ipcp->gid;
         context->ipc.mode = ipcp->mode;
+        context->ipc.has_perm = 0;
         security_ipc_getsecid(ipcp, &context->ipc.osid);
         context->type = AUDIT_IPC;
 }
@@ -2363,26 +2365,17 @@ void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
  * @gid: msgq group id
  * @mode: msgq mode (permissions)
  *
- * Returns 0 for success or NULL context or < 0 on error.
+ * Called only after audit_ipc_obj().
  */
-int __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
+void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
 {
-        struct audit_aux_data_ipcctl *ax;
         struct audit_context *context = current->audit_context;
 
-        ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
-        if (!ax)
-                return -ENOMEM;
-
-        ax->qbytes = qbytes;
-        ax->uid = uid;
-        ax->gid = gid;
-        ax->mode = mode;
-
-        ax->d.type = AUDIT_IPC_SET_PERM;
-        ax->d.next = context->aux;
-        context->aux = (void *)ax;
-        return 0;
+        context->ipc.qbytes = qbytes;
+        context->ipc.perm_uid = uid;
+        context->ipc.perm_gid = gid;
+        context->ipc.perm_mode = mode;
+        context->ipc.has_perm = 1;
 }
 
 int audit_bprm(struct linux_binprm *bprm)