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 6BD7E79C9 for ; Thu, 12 Jan 2023 14:18:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C5FB5C433D2; Thu, 12 Jan 2023 14:18:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673533090; bh=tP5GtcpL8y1odZI4Boe03MmjASKA2EbFGCclmc2dx8c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fgSrk0MQbD86x687nqQyGxAf4uUxfbWP6WHOHjbPsUlCci9ulGFJB82tmY9ewohMv 1L40C27kVC7WqZE+cK8mGjDE8blKkqLZTpu/ViNh5TGqrikhDr1m5TB341zq9xPLnM bGo08T9czaZ5Ybv7ZzsmpEwU8M3GD3LzNqFt5PRk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yang Yingliang , Andrew Donnellan , Frederic Barrat , Sasha Levin Subject: [PATCH 5.10 365/783] cxl: fix possible null-ptr-deref in cxl_guest_init_afu|adapter() Date: Thu, 12 Jan 2023 14:51:21 +0100 Message-Id: <20230112135541.261376836@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: Yang Yingliang [ Upstream commit 61c80d1c3833e196256fb060382db94f24d3d9a7 ] If device_register() fails in cxl_register_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: 14baf4d9c739 ("cxl: Add guest-specific code") Signed-off-by: Yang Yingliang Acked-by: Andrew Donnellan Acked-by: Frederic Barrat Link: https://lore.kernel.org/r/20221111145440.2426970-1-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/misc/cxl/guest.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/drivers/misc/cxl/guest.c b/drivers/misc/cxl/guest.c index 186308f1f8eb..6334376826a9 100644 --- a/drivers/misc/cxl/guest.c +++ b/drivers/misc/cxl/guest.c @@ -959,10 +959,10 @@ int cxl_guest_init_afu(struct cxl *adapter, int slice, struct device_node *afu_n * 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; /* * pHyp doesn't expose the programming models supported by the @@ -978,7 +978,7 @@ int cxl_guest_init_afu(struct cxl *adapter, int slice, struct device_node *afu_n afu->modes_supported = CXL_MODE_DIRECTED; if ((rc = cxl_afu_select_best_mode(afu))) - goto err_put2; + goto err_remove_sysfs; adapter->afu[afu->slice] = afu; @@ -998,10 +998,12 @@ int cxl_guest_init_afu(struct cxl *adapter, int slice, struct device_node *afu_n return 0; -err_put2: +err_remove_sysfs: cxl_sysfs_afu_remove(afu); -err_put1: - device_unregister(&afu->dev); +err_del_dev: + device_del(&afu->dev); +err_put_dev: + put_device(&afu->dev); free = false; guest_release_serr_irq(afu); err2: @@ -1135,18 +1137,20 @@ struct cxl *cxl_guest_init_adapter(struct device_node *np, struct platform_devic * 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 the adapter is configured */ cxl_adapter_context_unlock(adapter); return adapter; -err_put1: - device_unregister(&adapter->dev); +err_del_dev: + device_del(&adapter->dev); +err_put_dev: + put_device(&adapter->dev); free = false; cxl_guest_remove_chardev(adapter); err1: -- 2.35.1