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Diffstat (limited to 'ipc/msg.c')
-rw-r--r--ipc/msg.c32
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)) {
/*