From 87114373ea507895a62afb10d2910bd9adac35a8 Mon Sep 17 00:00:00 2001
From: Miklos Szeredi <mszeredi@redhat.com>
Date: Thu Jul 26 16:13:11 2018 +0200
Subject: [PATCH] fuse: fix double request_end()
Git-commit: 87114373ea507895a62afb10d2910bd9adac35a8
References: bsc#1106291
Patch-mainline: v4.19-rc1

Refcounting of request is broken when fuse_abort_conn() is called and
request is on the fpq->io list:

 - ref is taken too late
 - then it is not dropped

Fixes: 0d8e84b0432b ("fuse: simplify request abort")
Cc: <stable@vger.kernel.org> # v4.2
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Goldwyn Rodrigues <rgoldwyn@suse.com>

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index c6b88fa..8564d91 100644

--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -371,7 +371,7 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
 	struct fuse_iqueue *fiq = &fc->iq;
 
 	if (test_and_set_bit(FR_FINISHED, &req->flags))
-		return;
+		goto out_put_req;
 
 	spin_lock(&fiq->waitq.lock);
 	list_del_init(&req->intr_entry);
@@ -400,6 +400,7 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
 	wake_up(&req->waitq);
 	if (req->end)
 		req->end(fc, req);
+out_put_req:
 	fuse_put_request(fc, req);
 }
 
@@ -2105,6 +2106,7 @@ void fuse_abort_conn(struct fuse_conn *fc, bool is_abort)
 				set_bit(FR_ABORTED, &req->flags);
 				if (!test_bit(FR_LOCKED, &req->flags)) {
 					set_bit(FR_PRIVATE, &req->flags);
+					__fuse_get_request(req);
 					list_move(&req->list, &to_end1);
 				}
 				spin_unlock(&req->waitq.lock);
@@ -2131,7 +2133,6 @@ void fuse_abort_conn(struct fuse_conn *fc, bool is_abort)
 
 		while (!list_empty(&to_end1)) {
 			req = list_first_entry(&to_end1, struct fuse_req, list);
-			__fuse_get_request(req);
 			list_del_init(&req->list);
 			request_end(fc, req);
 		}