1 files changed, 21 insertions, 9 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index ec238fb..aa93f09 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -58,7 +58,7 @@ struct fuse_file *fuse_file_alloc(struct fuse_conn *fc)
 	}
 
 	INIT_LIST_HEAD(&ff->write_entry);
-	atomic_set(&ff->count, 1);
+	refcount_set(&ff->count, 1);
 	RB_CLEAR_NODE(&ff->polled_node);
 	init_waitqueue_head(&ff->poll_wait);
 
@@ -77,7 +77,7 @@ void fuse_file_free(struct fuse_file *ff)
 
 static struct fuse_file *fuse_file_get(struct fuse_file *ff)
 {
-	atomic_inc(&ff->count);
+	refcount_inc(&ff->count);
 	return ff;
 }
 
@@ -88,7 +88,7 @@ static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
 
 static void fuse_file_put(struct fuse_file *ff, bool sync)
 {
-	if (atomic_dec_and_test(&ff->count)) {
+	if (refcount_dec_and_test(&ff->count)) {
 		struct fuse_req *req = ff->reserved_req;
 
 		if (ff->fc->no_open) {
@@ -293,7 +293,7 @@ static int fuse_release(struct inode *inode, struct file *file)
 
 void fuse_sync_release(struct fuse_file *ff, int flags)
 {
-	WARN_ON(atomic_read(&ff->count) != 1);
+	WARN_ON(refcount_read(&ff->count) > 1);
 	fuse_prepare_release(ff, flags, FUSE_RELEASE);
 	/*
 	 * iput(NULL) is a no-op and since the refcount is 1 and everything's
@@ -2083,7 +2083,8 @@ static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma)
 	return generic_file_mmap(file, vma);
 }
 
-static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
+static int convert_fuse_file_lock(struct fuse_conn *fc,
+				  const struct fuse_file_lock *ffl,
 				  struct file_lock *fl)
 {
 	switch (ffl->type) {
@@ -2098,7 +2099,14 @@ static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
 
 		fl->fl_start = ffl->start;
 		fl->fl_end = ffl->end;
-		fl->fl_pid = ffl->pid;
+
+		/*
+		 * Convert pid into the caller's pid namespace. If the pid
+		 * does not map into the namespace fl_pid will get set to 0.
+		 */
+		rcu_read_lock();
+		fl->fl_pid = pid_vnr(find_pid_ns(ffl->pid, fc->pid_ns));
+		rcu_read_unlock();
 		break;
 
 	default:
@@ -2147,7 +2155,7 @@ static int fuse_getlk(struct file *file, struct file_lock *fl)
 	args.out.args[0].value = &outarg;
 	err = fuse_simple_request(fc, &args);
 	if (!err)
-		err = convert_fuse_file_lock(&outarg.lk, fl);
+		err = convert_fuse_file_lock(fc, &outarg.lk, fl);
 
 	return err;
 }
@@ -2159,7 +2167,8 @@ static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
 	FUSE_ARGS(args);
 	struct fuse_lk_in inarg;
 	int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
-	pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
+	struct pid *pid = fl->fl_type != F_UNLCK ? task_tgid(current) : NULL;
+	pid_t pid_nr = pid_nr_ns(pid, fc->pid_ns);
 	int err;
 
 	if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
@@ -2171,7 +2180,10 @@ static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
 	if (fl->fl_flags & FL_CLOSE)
 		return 0;
 
-	fuse_lk_fill(&args, file, fl, opcode, pid, flock, &inarg);
+	if (pid && pid_nr == 0)
+		return -EOVERFLOW;
+
+	fuse_lk_fill(&args, file, fl, opcode, pid_nr, flock, &inarg);
 	err = fuse_simple_request(fc, &args);
 
 	/* locking is restartable */