1 files changed, 26 insertions, 6 deletions

diff --git a/ipc/msg.c b/ipc/msg.c
index b0d541d42677..558aa91186b6 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -165,6 +165,15 @@ static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
         ipc_rmid(&msg_ids(ns), &s->q_perm);
 }
 
+static void msg_rcu_free(struct rcu_head *head)
+{
+        struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
+        struct msg_queue *msq = ipc_rcu_to_struct(p);
+
+        security_msg_queue_free(msq);
+        ipc_rcu_free(head);
+}
+
 /**
  * newque - Create a new msg queue
  * @ns: namespace
@@ -189,15 +198,14 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params)
         msq->q_perm.security = NULL;
         retval = security_msg_queue_alloc(msq);
         if (retval) {
-                ipc_rcu_putref(msq);
+                ipc_rcu_putref(msq, ipc_rcu_free);
                 return retval;
         }
 
         /* ipc_addid() locks msq upon success. */
         id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
         if (id < 0) {
-                security_msg_queue_free(msq);
-                ipc_rcu_putref(msq);
+                ipc_rcu_putref(msq, msg_rcu_free);
                 return id;
         }
 
@@ -276,8 +284,7 @@ static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
                 free_msg(msg);
         }
         atomic_sub(msq->q_cbytes, &ns->msg_bytes);
-        security_msg_queue_free(msq);
-        ipc_rcu_putref(msq);
+        ipc_rcu_putref(msq, msg_rcu_free);
 }
 
 /*
@@ -688,6 +695,12 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
                 if (ipcperms(ns, &msq->q_perm, S_IWUGO))
                         goto out_unlock0;
 
+                /* raced with RMID? */
+                if (msq->q_perm.deleted) {
+                        err = -EIDRM;
+                        goto out_unlock0;
+                }
+
                 err = security_msg_queue_msgsnd(msq, msg, msgflg);
                 if (err)
                         goto out_unlock0;
@@ -717,7 +730,7 @@ long do_msgsnd(int msqid, long mtype, void __user *mtext,
                 rcu_read_lock();
                 ipc_lock_object(&msq->q_perm);
 
-                ipc_rcu_putref(msq);
+                ipc_rcu_putref(msq, ipc_rcu_free);
                 if (msq->q_perm.deleted) {
                         err = -EIDRM;
                         goto out_unlock0;
@@ -894,6 +907,13 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgfl
                         goto out_unlock1;
 
                 ipc_lock_object(&msq->q_perm);
+
+                /* raced with RMID? */
+                if (msq->q_perm.deleted) {
+                        msg = ERR_PTR(-EIDRM);
+                        goto out_unlock0;
+                }
+
                 msg = find_msg(msq, &msgtyp, mode);
                 if (!IS_ERR(msg)) {
                         /*