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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Miklos Szeredi <mszeredi@redhat.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.12 074/363] virtiofs: fix userns
Date:   Mon, 17 May 2021 15:59:00 +0200
Message-Id: <20210517140305.092320987@linuxfoundation.org>
In-Reply-To: <20210517140302.508966430@linuxfoundation.org>
References: <20210517140302.508966430@linuxfoundation.org>
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From: Miklos Szeredi <mszeredi@redhat.com>

[ Upstream commit 0a7419c68a45d2d066b996be5087aa2d07ce80eb ]

get_user_ns() is done twice (once in virtio_fs_get_tree() and once in
fuse_conn_init()), resulting in a reference leak.

Also looks better to use fsc->user_ns (which *should* be the
current_user_ns() at this point).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/fuse/virtio_fs.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index 1e5affed158e..005209b1cd50 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -1437,8 +1437,7 @@ static int virtio_fs_get_tree(struct fs_context *fsc)
 	if (!fm)
 		goto out_err;
 
-	fuse_conn_init(fc, fm, get_user_ns(current_user_ns()),
-		       &virtio_fs_fiq_ops, fs);
+	fuse_conn_init(fc, fm, fsc->user_ns, &virtio_fs_fiq_ops, fs);
 	fc->release = fuse_free_conn;
 	fc->delete_stale = true;
 	fc->auto_submounts = true;
-- 
2.30.2