From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2C8CD79C9 for ; Thu, 12 Jan 2023 14:38:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8CA47C433D2; Thu, 12 Jan 2023 14:38:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673534307; bh=hN3guaYIXEqybB94lhygdS+xS9Bx+S+lt3n0V8w4uZw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u/XNuPqLPlcUI4i5GypDSBqI1Ucim1mUix94vzY89U1MtCPhHDdm5gT5jfk8oLkur wfvswgmQmoyvJbkzzc3q9cLmS6Xcj2+7M878mVOHjEE26P3fYInn45u7ysQcvj0xGY 0OMbNa9ghzhGwcyr6+6bpb1RhsrXvvu84AXoBF40= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yuan Can , "Michael S. Tsirkin" , Stefano Garzarella , Jason Wang , Sasha Levin Subject: [PATCH 5.10 734/783] vhost/vsock: Fix error handling in vhost_vsock_init() Date: Thu, 12 Jan 2023 14:57:30 +0100 Message-Id: <20230112135558.364958577@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230112135524.143670746@linuxfoundation.org> References: <20230112135524.143670746@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Yuan Can [ Upstream commit 7a4efe182ca61fb3e5307e69b261c57cbf434cd4 ] A problem about modprobe vhost_vsock failed is triggered with the following log given: modprobe: ERROR: could not insert 'vhost_vsock': Device or resource busy The reason is that vhost_vsock_init() returns misc_register() directly without checking its return value, if misc_register() failed, it returns without calling vsock_core_unregister() on vhost_transport, resulting the vhost_vsock can never be installed later. A simple call graph is shown as below: vhost_vsock_init() vsock_core_register() # register vhost_transport misc_register() device_create_with_groups() device_create_groups_vargs() dev = kzalloc(...) # OOM happened # return without unregister vhost_transport Fix by calling vsock_core_unregister() when misc_register() returns error. Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko") Signed-off-by: Yuan Can Message-Id: <20221108101705.45981-1-yuancan@huawei.com> Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefano Garzarella Acked-by: Jason Wang Signed-off-by: Sasha Levin --- drivers/vhost/vsock.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index b0153617fe0e..7bce5f982e58 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -854,7 +854,14 @@ static int __init vhost_vsock_init(void) VSOCK_TRANSPORT_F_H2G); if (ret < 0) return ret; - return misc_register(&vhost_vsock_misc); + + ret = misc_register(&vhost_vsock_misc); + if (ret) { + vsock_core_unregister(&vhost_transport.transport); + return ret; + } + + return 0; }; static void __exit vhost_vsock_exit(void) -- 2.35.1