From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christoph Hellwig , Bjorn Helgaas , Johannes Thumshirn , Keith Busch , Sasha Levin Subject: [PATCH 4.17 111/336] PCI: Prevent sysfs disable of device while driver is attached Date: Wed, 1 Aug 2018 18:47:26 +0200 Message-Id: <20180801165033.403130732@linuxfoundation.org> In-Reply-To: <20180801165028.930831994@linuxfoundation.org> References: <20180801165028.930831994@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christoph Hellwig [ Upstream commit 6f5cdfa802733dcb561bf664cc89d203f2fd958f ] Manipulating the enable_cnt behind the back of the driver will wreak complete havoc with the kernel state, so disallow it. Signed-off-by: Christoph Hellwig Signed-off-by: Bjorn Helgaas Reviewed-by: Johannes Thumshirn Acked-by: Keith Busch Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci-sysfs.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -288,13 +288,16 @@ static ssize_t enable_store(struct devic if (!capable(CAP_SYS_ADMIN)) return -EPERM; - if (!val) { - if (pci_is_enabled(pdev)) - pci_disable_device(pdev); - else - result = -EIO; - } else + device_lock(dev); + if (dev->driver) + result = -EBUSY; + else if (val) result = pci_enable_device(pdev); + else if (pci_is_enabled(pdev)) + pci_disable_device(pdev); + else + result = -EIO; + device_unlock(dev); return result < 0 ? result : count; }