Merge tag 'locks-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/…

…git/jlayton/linux

Pull file locking fixes from Jeff Layton:
 "A fix for some undefined integer overflow behavior, a typo in a
  comment header, and a fix for a potential deadlock involving internal
  senders of SIGIO/SIGURG"

* tag 'locks-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
  fcntl: Fix potential deadlock in send_sig{io, urg}()
  locks: fix a typo at a kernel-doc markup
  locks: Fix UBSAN undefined behaviour in flock64_to_posix_lock

fs/fcntl.c

@@ -781,9 +781,10 @@ void send_sigio(struct fown_struct *fown, int fd, int band)
 {
 	struct task_struct *p;
 	enum pid_type type;
+	unsigned long flags;
 	struct pid *pid;
 
-	read_lock(&fown->lock);
+	read_lock_irqsave(&fown->lock, flags);
 
 	type = fown->pid_type;
 	pid = fown->pid;
@@ -804,7 +805,7 @@ void send_sigio(struct fown_struct *fown, int fd, int band)
 		read_unlock(&tasklist_lock);
 	}
  out_unlock_fown:
-	read_unlock(&fown->lock);
+	read_unlock_irqrestore(&fown->lock, flags);
 }
 
 static void send_sigurg_to_task(struct task_struct *p,
@@ -819,9 +820,10 @@ int send_sigurg(struct fown_struct *fown)
 	struct task_struct *p;
 	enum pid_type type;
 	struct pid *pid;
+	unsigned long flags;
 	int ret = 0;
 
-	read_lock(&fown->lock);
+	read_lock_irqsave(&fown->lock, flags);
 
 	type = fown->pid_type;
 	pid = fown->pid;
@@ -844,7 +846,7 @@ int send_sigurg(struct fown_struct *fown)
 		read_unlock(&tasklist_lock);
 	}
  out_unlock_fown:
-	read_unlock(&fown->lock);
+	read_unlock_irqrestore(&fown->lock, flags);
 	return ret;
 }
 

fs/locks.c

@@ -542,7 +542,7 @@ static int flock64_to_posix_lock(struct file *filp, struct file_lock *fl,
 	if (l->l_len > 0) {
 		if (l->l_len - 1 > OFFSET_MAX - fl->fl_start)
 			return -EOVERFLOW;
-		fl->fl_end = fl->fl_start + l->l_len - 1;
+		fl->fl_end = fl->fl_start + (l->l_len - 1);
 
 	} else if (l->l_len < 0) {
 		if (fl->fl_start + l->l_len < 0)
@@ -750,7 +750,7 @@ static void __locks_wake_up_blocks(struct file_lock *blocker)
 }
 
 /**
- *	locks_delete_lock - stop waiting for a file lock
+ *	locks_delete_block - stop waiting for a file lock
  *	@waiter: the lock which was waiting
  *
  *	lockd/nfsd need to disconnect the lock while working on it.