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 96B8E1863 for ; Wed, 28 Dec 2022 15:30:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0065AC433EF; Wed, 28 Dec 2022 15:30:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672241408; bh=EpxBNJwcm9a8nfr5KG8vZQngwl1afZwch0/a3FladsU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OJW1bPz30XFzMDgL6n3EiWVwIHOjlxJWmw60OX/IDG/L3oNCjQ0SobcWUgLF7NSDF 0sNmbMslKViudXNIBclz0aP4Y3YfIcFoT+BTrlU0alqEy1S9V6QXmV8bG9iaSgGCEJ ua1xtdwg0GszQygwT6ekgSE+eqqCprDRmi5xyTq0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yang Yingliang , Frederic Barrat , Andrew Donnellan , Sasha Levin Subject: [PATCH 5.15 472/731] cxl: fix possible null-ptr-deref in cxl_pci_init_afu|adapter() Date: Wed, 28 Dec 2022 15:39:39 +0100 Message-Id: <20221228144310.233108783@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144256.536395940@linuxfoundation.org> References: <20221228144256.536395940@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: Yang Yingliang [ Upstream commit 02cd3032b154fa02fdf90e7467abaeed889330b2 ] If device_register() fails in cxl_pci_afu|adapter(), the device is not added, device_unregister() can not be called in the error path, otherwise it will cause a null-ptr-deref because of removing not added device. As comment of device_register() says, it should use put_device() to give up the reference in the error path. So split device_unregister() into device_del() and put_device(), then goes to put dev when register fails. Fixes: f204e0b8cedd ("cxl: Driver code for powernv PCIe based cards for userspace access") Signed-off-by: Yang Yingliang Acked-by: Frederic Barrat Acked-by: Andrew Donnellan Link: https://lore.kernel.org/r/20221111145440.2426970-2-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/misc/cxl/pci.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index 2ba899f5659f..0ac3f4cb88ac 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -1164,10 +1164,10 @@ static int pci_init_afu(struct cxl *adapter, int slice, struct pci_dev *dev) * if it returns an error! */ if ((rc = cxl_register_afu(afu))) - goto err_put1; + goto err_put_dev; if ((rc = cxl_sysfs_afu_add(afu))) - goto err_put1; + goto err_del_dev; adapter->afu[afu->slice] = afu; @@ -1176,10 +1176,12 @@ static int pci_init_afu(struct cxl *adapter, int slice, struct pci_dev *dev) return 0; -err_put1: +err_del_dev: + device_del(&afu->dev); +err_put_dev: pci_deconfigure_afu(afu); cxl_debugfs_afu_remove(afu); - device_unregister(&afu->dev); + put_device(&afu->dev); return rc; err_free_native: @@ -1667,23 +1669,25 @@ static struct cxl *cxl_pci_init_adapter(struct pci_dev *dev) * even if it returns an error! */ if ((rc = cxl_register_adapter(adapter))) - goto err_put1; + goto err_put_dev; if ((rc = cxl_sysfs_adapter_add(adapter))) - goto err_put1; + goto err_del_dev; /* Release the context lock as adapter is configured */ cxl_adapter_context_unlock(adapter); return adapter; -err_put1: +err_del_dev: + device_del(&adapter->dev); +err_put_dev: /* This should mirror cxl_remove_adapter, except without the * sysfs parts */ cxl_debugfs_adapter_remove(adapter); cxl_deconfigure_adapter(adapter); - device_unregister(&adapter->dev); + put_device(&adapter->dev); return ERR_PTR(rc); err_release: -- 2.35.1