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 40697A93F for ; Tue, 10 Jan 2023 18:16:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99C61C433F0; Tue, 10 Jan 2023 18:16:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673374608; bh=hheDl6dpJScVhrmPq2AAcUlVM0ti6E2A5kbDfg9FTRI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KrHyrUCgD1kpawugZpeV8V6fXgkr3L8cLU+ifw8cDvChVMbBRwlDFZJDouJNQ+Oey BDaDHaHUMD1f7d1q9lRrRxL0MH933l3mG1kUTpd1qeVyXr6KQrlmlR3GvaFKaxzrSr GgOduTAw9b6SkaKQAprK+2+ZvNdLLxnod3TGi3Sg= 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 6.1 043/159] vhost/vsock: Fix error handling in vhost_vsock_init() Date: Tue, 10 Jan 2023 19:03:11 +0100 Message-Id: <20230110180019.683589816@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230110180018.288460217@linuxfoundation.org> References: <20230110180018.288460217@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 5703775af129..10a7d23731fe 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -959,7 +959,14 @@ 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