Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751936AbcDJTlt (ORCPT ); Sun, 10 Apr 2016 15:41:49 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54666 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933191AbcDJTS5 (ORCPT ); Sun, 10 Apr 2016 15:18:57 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shawn Lin , Ulf Hansson Subject: [PATCH 4.4 173/210] mmc: block: fix ABI regression of mmc_blk_ioctl Date: Sun, 10 Apr 2016 11:36:34 -0700 Message-Id: <20160410183532.780083296@linuxfoundation.org> X-Mailer: git-send-email 2.8.0 In-Reply-To: <20160410183526.651820045@linuxfoundation.org> References: <20160410183526.651820045@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2651 Lines: 77 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shawn Lin commit 83c742c344c08c2bbe338d45c6ec63110e9d5e3d upstream. If mmc_blk_ioctl returns -EINVAL, blkdev_ioctl continues to work without returning err to user-space. But now we check CAP_SYS_RAWIO firstly, so we return -EPERM to blkdev_ioctl, which make blkdev_ioctl return -EPERM to user-space directly. So this will break all the ioctl with BLKROSET. Now we find Android-adb suffer it for the following log: remount of /system failed; couldn't make block device writable: Operation not permitted openat(AT_FDCWD, "/dev/block/platform/ff420000.dwmmc/by-name/system", O_RDONLY) = 3 ioctl(3, BLKROSET, 0) = -1 EPERM (Operation not permitted) Fixes: a5f5774c55a2 ("mmc: block: Add new ioctl to send multi commands") Signed-off-by: Shawn Lin Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman --- drivers/mmc/card/block.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -596,6 +596,14 @@ static int mmc_blk_ioctl_cmd(struct bloc struct mmc_card *card; int err = 0, ioc_err = 0; + /* + * The caller must have CAP_SYS_RAWIO, and must be calling this on the + * whole block device, not on a partition. This prevents overspray + * between sibling partitions. + */ + if ((!capable(CAP_SYS_RAWIO)) || (bdev != bdev->bd_contains)) + return -EPERM; + idata = mmc_blk_ioctl_copy_from_user(ic_ptr); if (IS_ERR(idata)) return PTR_ERR(idata); @@ -638,6 +646,14 @@ static int mmc_blk_ioctl_multi_cmd(struc int i, err = 0, ioc_err = 0; __u64 num_of_cmds; + /* + * The caller must have CAP_SYS_RAWIO, and must be calling this on the + * whole block device, not on a partition. This prevents overspray + * between sibling partitions. + */ + if ((!capable(CAP_SYS_RAWIO)) || (bdev != bdev->bd_contains)) + return -EPERM; + if (copy_from_user(&num_of_cmds, &user->num_of_cmds, sizeof(num_of_cmds))) return -EFAULT; @@ -693,14 +709,6 @@ cmd_err: static int mmc_blk_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) { - /* - * The caller must have CAP_SYS_RAWIO, and must be calling this on the - * whole block device, not on a partition. This prevents overspray - * between sibling partitions. - */ - if ((!capable(CAP_SYS_RAWIO)) || (bdev != bdev->bd_contains)) - return -EPERM; - switch (cmd) { case MMC_IOC_CMD: return mmc_blk_ioctl_cmd(bdev,