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 BA14DBA49 for ; Tue, 7 Mar 2023 18:58:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1EED6C433D2; Tue, 7 Mar 2023 18:58:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678215493; bh=A5HJdnSxh23cWgckVVrpknU8kEuhs7V0gHl/DjM8f9M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bg3nzNCqi2B+mpWmaLpjLlu6QHt4x7gptiuxTmc82b6N1MptoP128XvcKGUTZrZke nkChm4mNLK5XAAP7DGYIIL9woNoVrrBBcKkIVZv1i/O5PtvjqC5NWadr5matEl/MgJ ocXYwr2F4acMg8/M9wOfQq7VBtbeYvIHORzUTH4Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yang Yingliang , Sasha Levin Subject: [PATCH 5.15 279/567] driver core: fix potential null-ptr-deref in device_add() Date: Tue, 7 Mar 2023 18:00:15 +0100 Message-Id: <20230307165917.984528363@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307165905.838066027@linuxfoundation.org> References: <20230307165905.838066027@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 f6837f34a34973ef6600c08195ed300e24e97317 ] I got the following null-ptr-deref report while doing fault injection test: BUG: kernel NULL pointer dereference, address: 0000000000000058 CPU: 2 PID: 278 Comm: 37-i2c-ds2482 Tainted: G B W N 6.1.0-rc3+ RIP: 0010:klist_put+0x2d/0xd0 Call Trace: klist_remove+0xf1/0x1c0 device_release_driver_internal+0x196/0x210 bus_remove_device+0x1bd/0x240 device_add+0xd3d/0x1100 w1_add_master_device+0x476/0x490 [wire] ds2482_probe+0x303/0x3e0 [ds2482] This is how it happened: w1_alloc_dev() // The dev->driver is set to w1_master_driver. memcpy(&dev->dev, device, sizeof(struct device)); device_add() bus_add_device() dpm_sysfs_add() // It fails, calls bus_remove_device. // error path bus_remove_device() // The dev->driver is not null, but driver is not bound. __device_release_driver() klist_remove(&dev->p->knode_driver) <-- It causes null-ptr-deref. // normal path bus_probe_device() // It's not called yet. device_bind_driver() If dev->driver is set, in the error path after calling bus_add_device() in device_add(), bus_remove_device() is called, then the device will be detached from driver. But device_bind_driver() is not called yet, so it causes null-ptr-deref while access the 'knode_driver'. To fix this, set dev->driver to null in the error path before calling bus_remove_device(). Fixes: 57eee3d23e88 ("Driver core: Call device_pm_add() after bus_add_device() in device_add()") Signed-off-by: Yang Yingliang Link: https://lore.kernel.org/r/20221205034904.2077765-1-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/base/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/base/core.c b/drivers/base/core.c index 10e027e926926..e6a7b93760e45 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -3428,6 +3428,7 @@ int device_add(struct device *dev) device_pm_remove(dev); dpm_sysfs_remove(dev); DPMError: + dev->driver = NULL; bus_remove_device(dev); BusError: device_remove_attrs(dev); -- 2.39.2