Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Anatoly Trosinenko <anatoly.trosinenko@gmail.com>,
        Miklos Szeredi <mszeredi@redhat.com>
Subject: [PATCH 5.4 063/348] fuse: reject internal errno
Date:   Mon, 12 Jul 2021 08:07:27 +0200
Message-Id: <20210712060710.441739464@linuxfoundation.org>
In-Reply-To: <20210712060659.886176320@linuxfoundation.org>
References: <20210712060659.886176320@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Miklos Szeredi <mszeredi@redhat.com>

commit 49221cf86d18bb66fe95d3338cb33bd4b9880ca5 upstream.

Don't allow userspace to report errors that could be kernel-internal.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Fixes: 334f485df85a ("[PATCH] FUSE - device functions")
Cc: <stable@vger.kernel.org> # v2.6.14
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/fuse/dev.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1869,7 +1869,7 @@ static ssize_t fuse_dev_do_write(struct
 	}
 
 	err = -EINVAL;
-	if (oh.error <= -1000 || oh.error > 0)
+	if (oh.error <= -512 || oh.error > 0)
 		goto copy_finish;
 
 	spin_lock(&fpq->lock);