Merge tag 'fuse-fixes-5.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse fix from Miklos Szeredi:
 "Fix an Oops introduced in v5.4"

* tag 'fuse-fixes-5.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: fix stack use after return

Author: torvalds

fs/fuse/dev.c

@@ -276,12 +276,10 @@ static void flush_bg_queue(struct fuse_conn *fc)
 void fuse_request_end(struct fuse_conn *fc, struct fuse_req *req)
 {
 	struct fuse_iqueue *fiq = &fc->iq;
-	bool async;
 
 	if (test_and_set_bit(FR_FINISHED, &req->flags))
 		goto put_request;
 
-	async = req->args->end;
 	/*
 	 * test_and_set_bit() implies smp_mb() between bit
 	 * changing and below intr_entry check. Pairs with
@@ -324,7 +322,7 @@ void fuse_request_end(struct fuse_conn *fc, struct fuse_req *req)
 		wake_up(&req->waitq);
 	}
 
-	if (async)
+	if (test_bit(FR_ASYNC, &req->flags))
 		req->args->end(fc, req->args, req->out.h.error);
 put_request:
 	fuse_put_request(fc, req);
@@ -471,6 +469,8 @@ static void fuse_args_to_req(struct fuse_req *req, struct fuse_args *args)
 	req->in.h.opcode = args->opcode;
 	req->in.h.nodeid = args->nodeid;
 	req->args = args;
+	if (args->end)
+		__set_bit(FR_ASYNC, &req->flags);
 }
 
 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)

fs/fuse/fuse_i.h

@@ -301,6 +301,7 @@ struct fuse_io_priv {
  * FR_SENT:		request is in userspace, waiting for an answer
  * FR_FINISHED:		request is finished
  * FR_PRIVATE:		request is on private list
+ * FR_ASYNC:		request is asynchronous
  */
 enum fuse_req_flag {
 	FR_ISREPLY,
@@ -314,6 +315,7 @@ enum fuse_req_flag {
 	FR_SENT,
 	FR_FINISHED,
 	FR_PRIVATE,
+	FR_ASYNC,
 };
 
 /**