From patchwork Tue Mar 15 23:24:42 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 597906 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 3qPrM41Cdjz9sCk; Wed, 16 Mar 2016 10:25:20 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1afyKz-0002JG-7k; Tue, 15 Mar 2016 23:25:17 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1afyKV-00023T-U0 for kernel-team@lists.ubuntu.com; Tue, 15 Mar 2016 23:24:47 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1afyKT-00014b-VZ; Tue, 15 Mar 2016 23:24:46 +0000 Received: from kamal by fourier with local (Exim 4.86) (envelope-from ) id 1afyKR-0004mi-9h; Tue, 15 Mar 2016 16:24:43 -0700 From: Kamal Mostafa To: Arnd Bergmann Subject: [4.2.y-ckt stable] Patch "libata: fix HDIO_GET_32BIT ioctl" has been added to the 4.2.y-ckt tree Date: Tue, 15 Mar 2016 16:24:42 -0700 Message-Id: <1458084282-18357-1-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.0 X-Extended-Stable: 4.2 Cc: Tejun Heo , Kamal Mostafa , kernel-team@lists.ubuntu.com, Soohoon Lee X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled libata: fix HDIO_GET_32BIT ioctl to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue This patch is scheduled to be released in version 4.2.8-ckt6. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 4.2.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From 07222ab6be486dc8cf76d647ec3e32d75391c2d3 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 11 Feb 2016 14:16:27 +0100 Subject: libata: fix HDIO_GET_32BIT ioctl commit 287e6611ab1eac76c2c5ebf6e345e04c80ca9c61 upstream. As reported by Soohoon Lee, the HDIO_GET_32BIT ioctl does not work correctly in compat mode with libata. I have investigated the issue further and found multiple problems that all appeared with the same commit that originally introduced HDIO_GET_32BIT handling in libata back in linux-2.6.8 and presumably also linux-2.4, as the code uses "copy_to_user(arg, &val, 1)" to copy a 'long' variable containing either 0 or 1 to user space. The problems with this are: * On big-endian machines, this will always write a zero because it stores the wrong byte into user space. * In compat mode, the upper three bytes of the variable are updated by the compat_hdio_ioctl() function, but they now contain uninitialized stack data. * The hdparm tool calling this ioctl uses a 'static long' variable to store the result. This means at least the upper bytes are initialized to zero, but calling another ioctl like HDIO_GET_MULTCOUNT would fill them with data that remains stale when the low byte is overwritten. Fortunately libata doesn't implement any of the affected ioctl commands, so this would only happen when we query both an IDE and an ATA device in the same command such as "hdparm -N -c /dev/hda /dev/sda" * The libata code for unknown reasons started using ATA_IOC_GET_IO32 and ATA_IOC_SET_IO32 as aliases for HDIO_GET_32BIT and HDIO_SET_32BIT, while the ioctl commands that were added later use the normal HDIO_* names. This is harmless but rather confusing. This addresses all four issues by changing the code to use put_user() on an 'unsigned long' variable in HDIO_GET_32BIT, like the IDE subsystem does, and by clarifying the names of the ioctl commands. Signed-off-by: Arnd Bergmann Reported-by: Soohoon Lee Tested-by: Soohoon Lee Signed-off-by: Tejun Heo Signed-off-by: Kamal Mostafa --- drivers/ata/libata-scsi.c | 11 +++++------ include/linux/ata.h | 4 ++-- 2 files changed, 7 insertions(+), 8 deletions(-) -- 2.7.0 diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 0d7f0da..ae7cfcb 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -675,19 +675,18 @@ static int ata_ioc32(struct ata_port *ap) int ata_sas_scsi_ioctl(struct ata_port *ap, struct scsi_device *scsidev, int cmd, void __user *arg) { - int val = -EINVAL, rc = -EINVAL; + unsigned long val; + int rc = -EINVAL; unsigned long flags; switch (cmd) { - case ATA_IOC_GET_IO32: + case HDIO_GET_32BIT: spin_lock_irqsave(ap->lock, flags); val = ata_ioc32(ap); spin_unlock_irqrestore(ap->lock, flags); - if (copy_to_user(arg, &val, 1)) - return -EFAULT; - return 0; + return put_user(val, (unsigned long __user *)arg); - case ATA_IOC_SET_IO32: + case HDIO_SET_32BIT: val = (unsigned long) arg; rc = 0; spin_lock_irqsave(ap->lock, flags); diff --git a/include/linux/ata.h b/include/linux/ata.h index d2992bf..c1a2f34 100644 --- a/include/linux/ata.h +++ b/include/linux/ata.h @@ -487,8 +487,8 @@ enum ata_tf_protocols { }; enum ata_ioctls { - ATA_IOC_GET_IO32 = 0x309, - ATA_IOC_SET_IO32 = 0x324, + ATA_IOC_GET_IO32 = 0x309, /* HDIO_GET_32BIT */ + ATA_IOC_SET_IO32 = 0x324, /* HDIO_SET_32BIT */ }; /* core structures */