[v2.6.34-stable 010/213] block: add and use scsi_blk_cmd_ioctl

[v2.6.34-stable 010/213] block: add and use scsi_blk_cmd_ioctl

[Paul Gortmaker]

From: Paolo Bonzini <pbonzini@redhat.com>

                   -------------------
    This is a commit scheduled for the next v2.6.34 longterm release.
    http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
    If you see a problem with using this for longterm, please comment.
                   -------------------

commit 577ebb374c78314ac4617242f509e2f5e7156649 upstream.

Introduce a wrapper around scsi_cmd_ioctl that takes a block device.

The function will then be enhanced to detect partition block devices
and, in that case, subject the ioctls to whitelisting.

Cc: linux-scsi@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: James Bottomley <JBottomley@parallels.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 block/scsi_ioctl.c             | 7 +++++++
 drivers/block/cciss.c          | 6 +++---
 drivers/block/ub.c             | 3 +--
 drivers/block/virtio_blk.c     | 4 ++--
 drivers/cdrom/cdrom.c          | 3 +--
 drivers/ide/ide-floppy_ioctl.c | 3 +--
 drivers/scsi/sd.c              | 2 +-
 include/linux/blkdev.h         | 2 ++
 8 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 4f4230b79bb6..57ac93754841 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -691,6 +691,13 @@ int scsi_cmd_ioctl(struct request_queue *q, struct gendisk *bd_disk, fmode_t mod
 }
 EXPORT_SYMBOL(scsi_cmd_ioctl);
 
+int scsi_cmd_blk_ioctl(struct block_device *bd, fmode_t mode,
+		       unsigned int cmd, void __user *arg)
+{
+	return scsi_cmd_ioctl(bd->bd_disk->queue, bd->bd_disk, mode, cmd, arg);
+}
+EXPORT_SYMBOL(scsi_cmd_blk_ioctl);
+
 static int __init blk_scsi_ioctl_init(void)
 {
 	blk_set_cmd_filter_defaults(&blk_default_cmd_filter);
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index eb5ff0531cfb..54bad7584ea4 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -1652,7 +1652,7 @@ static int cciss_ioctl(struct block_device *bdev, fmode_t mode,
 			return status;
 		}
 
-	/* scsi_cmd_ioctl handles these, below, though some are not */
+	/* scsi_cmd_blk_ioctl handles these, below, though some are not */
 	/* very meaningful for cciss.  SG_IO is the main one people want. */
 
 	case SG_GET_VERSION_NUM:
@@ -1663,9 +1663,9 @@ static int cciss_ioctl(struct block_device *bdev, fmode_t mode,
 	case SG_EMULATED_HOST:
 	case SG_IO:
 	case SCSI_IOCTL_SEND_COMMAND:
-		return scsi_cmd_ioctl(disk->queue, disk, mode, cmd, argp);
+		return scsi_cmd_blk_ioctl(bdev, mode, cmd, argp);
 
-	/* scsi_cmd_ioctl would normally handle these, below, but */
+	/* scsi_cmd_blk_ioctl would normally handle these, below, but */
 	/* they aren't a good fit for cciss, as CD-ROMs are */
 	/* not supported, and we don't have any bus/target/lun */
 	/* which we present to the kernel. */
diff --git a/drivers/block/ub.c b/drivers/block/ub.c
index 0536b5b29adc..1c1533a59c4d 100644
--- a/drivers/block/ub.c
+++ b/drivers/block/ub.c
@@ -1727,10 +1727,9 @@ static int ub_bd_release(struct gendisk *disk, fmode_t mode)
 static int ub_bd_ioctl(struct block_device *bdev, fmode_t mode,
     unsigned int cmd, unsigned long arg)
 {
-	struct gendisk *disk = bdev->bd_disk;
 	void __user *usermem = (void __user *) arg;
 
-	return scsi_cmd_ioctl(disk->queue, disk, mode, cmd, usermem);
+	return scsi_cmd_blk_ioctl(bdev, mode, cmd, usermem);
 }
 
 /*
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 2138a7ae050c..4abfa80fdcd6 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -201,8 +201,8 @@ static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
 	if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI))
 		return -ENOTTY;
 
-	return scsi_cmd_ioctl(disk->queue, disk, mode, cmd,
-			      (void __user *)data);
+	return scsi_cmd_blk_ioctl(bdev, mode, cmd,
+				  (void __user *)data);
 }
 
 /* We provide getgeo only to please some old bootloader/partitioning tools */
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index e3749d0ba68b..5e7c72d3fe39 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2684,12 +2684,11 @@ int cdrom_ioctl(struct cdrom_device_info *cdi, struct block_device *bdev,
 {
 	void __user *argp = (void __user *)arg;
 	int ret;
-	struct gendisk *disk = bdev->bd_disk;
 
 	/*
 	 * Try the generic SCSI command ioctl's first.
 	 */
-	ret = scsi_cmd_ioctl(disk->queue, disk, mode, cmd, argp);
+	ret = scsi_cmd_blk_ioctl(bdev, mode, cmd, argp);
 	if (ret != -ENOTTY)
 		return ret;
 
diff --git a/drivers/ide/ide-floppy_ioctl.c b/drivers/ide/ide-floppy_ioctl.c
index 9c2288234dea..05f024caf4c9 100644
--- a/drivers/ide/ide-floppy_ioctl.c
+++ b/drivers/ide/ide-floppy_ioctl.c
@@ -287,8 +287,7 @@ int ide_floppy_ioctl(ide_drive_t *drive, struct block_device *bdev,
 	 * and CDROM_SEND_PACKET (legacy) ioctls
 	 */
 	if (cmd != CDROM_SEND_PACKET && cmd != SCSI_IOCTL_SEND_COMMAND)
-		err = scsi_cmd_ioctl(bdev->bd_disk->queue, bdev->bd_disk,
-				mode, cmd, argp);
+		err = scsi_cmd_blk_ioctl(bdev, mode, cmd, argp);
 
 	if (err == -ENOTTY)
 		err = generic_ide_ioctl(drive, bdev, cmd, arg);
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 18e6c59ed12d..654e2674e7c3 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -907,7 +907,7 @@ static int sd_ioctl(struct block_device *bdev, fmode_t mode,
 		case SCSI_IOCTL_GET_BUS_NUMBER:
 			return scsi_ioctl(sdp, cmd, p);
 		default:
-			error = scsi_cmd_ioctl(disk->queue, disk, mode, cmd, p);
+			error = scsi_cmd_blk_ioctl(bdev, mode, cmd, p);
 			if (error != -ENOTTY)
 				return error;
 	}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index cda62da68108..ba55e497f7dc 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -793,6 +793,8 @@ extern void blk_plug_device(struct request_queue *);
 extern void blk_plug_device_unlocked(struct request_queue *);
 extern int blk_remove_plug(struct request_queue *);
 extern void blk_recount_segments(struct request_queue *, struct bio *);
+extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
+			      unsigned int, void __user *);
 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 			  unsigned int, void __user *);
 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
-- 
1.8.5.2

[v2.6.34-stable 011/213] block: fail SCSI passthrough ioctls on partition devices

[Paul Gortmaker]

From: Paolo Bonzini <pbonzini@redhat.com>

                   -------------------
    This is a commit scheduled for the next v2.6.34 longterm release.
    http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
    If you see a problem with using this for longterm, please comment.
                   -------------------

commit 0bfc96cb77224736dfa35c3c555d37b3646ef35e upstream.

Linux allows executing the SG_IO ioctl on a partition or LVM volume, and
will pass the command to the underlying block device.  This is
well-known, but it is also a large security problem when (via Unix
permissions, ACLs, SELinux or a combination thereof) a program or user
needs to be granted access only to part of the disk.

This patch lets partitions forward a small set of harmless ioctls;
others are logged with printk so that we can see which ioctls are
actually sent.  In my tests only CDROM_GET_CAPABILITY actually occurred.
Of course it was being sent to a (partition on a) hard disk, so it would
have failed with ENOTTY and the patch isn't changing anything in
practice.  Still, I'm treating it specially to avoid spamming the logs.

In principle, this restriction should include programs running with
CAP_SYS_RAWIO.  If for example I let a program access /dev/sda2 and
/dev/sdb, it still should not be able to read/write outside the
boundaries of /dev/sda2 independent of the capabilities.  However, for
now programs with CAP_SYS_RAWIO will still be allowed to send the
ioctls.  Their actions will still be logged.

This patch does not affect the non-libata IDE driver.  That driver
however already tests for bd != bd->bd_contains before issuing some
ioctl; it could be restricted further to forbid these ioctls even for
programs running with CAP_SYS_ADMIN/CAP_SYS_RAWIO.

Cc: linux-scsi@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: James Bottomley <JBottomley@parallels.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[ Make it also print the command name when warning - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 block/scsi_ioctl.c     | 45 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/scsi/sd.c      | 11 +++++++++--
 include/linux/blkdev.h |  1 +
 3 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 57ac93754841..b661f8940ef5 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -24,6 +24,7 @@
 #include <linux/capability.h>
 #include <linux/completion.h>
 #include <linux/cdrom.h>
+#include <linux/ratelimit.h>
 #include <linux/slab.h>
 #include <linux/times.h>
 #include <asm/uaccess.h>
@@ -691,9 +692,53 @@ int scsi_cmd_ioctl(struct request_queue *q, struct gendisk *bd_disk, fmode_t mod
 }
 EXPORT_SYMBOL(scsi_cmd_ioctl);
 
+int scsi_verify_blk_ioctl(struct block_device *bd, unsigned int cmd)
+{
+	if (bd && bd == bd->bd_contains)
+		return 0;
+
+	/* Actually none of these is particularly useful on a partition,
+	 * but they are safe.
+	 */
+	switch (cmd) {
+	case SCSI_IOCTL_GET_IDLUN:
+	case SCSI_IOCTL_GET_BUS_NUMBER:
+	case SCSI_IOCTL_GET_PCI:
+	case SCSI_IOCTL_PROBE_HOST:
+	case SG_GET_VERSION_NUM:
+	case SG_SET_TIMEOUT:
+	case SG_GET_TIMEOUT:
+	case SG_GET_RESERVED_SIZE:
+	case SG_SET_RESERVED_SIZE:
+	case SG_EMULATED_HOST:
+		return 0;
+	case CDROM_GET_CAPABILITY:
+		/* Keep this until we remove the printk below.  udev sends it
+		 * and we do not want to spam dmesg about it.   CD-ROMs do
+		 * not have partitions, so we get here only for disks.
+		 */
+		return -ENOIOCTLCMD;
+	default:
+		break;
+	}
+
+	/* In particular, rule out all resets and host-specific ioctls.  */
+	printk_ratelimited(KERN_WARNING
+			   "%s: sending ioctl %x to a partition!\n", current->comm, cmd);
+
+	return capable(CAP_SYS_RAWIO) ? 0 : -ENOIOCTLCMD;
+}
+EXPORT_SYMBOL(scsi_verify_blk_ioctl);
+
 int scsi_cmd_blk_ioctl(struct block_device *bd, fmode_t mode,
 		       unsigned int cmd, void __user *arg)
 {
+	int ret;
+
+	ret = scsi_verify_blk_ioctl(bd, cmd);
+	if (ret < 0)
+		return ret;
+
 	return scsi_cmd_ioctl(bd->bd_disk->queue, bd->bd_disk, mode, cmd, arg);
 }
 EXPORT_SYMBOL(scsi_cmd_blk_ioctl);
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 654e2674e7c3..1b543a229487 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -886,6 +886,10 @@ static int sd_ioctl(struct block_device *bdev, fmode_t mode,
 	SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n",
 						disk->disk_name, cmd));
 
+	error = scsi_verify_blk_ioctl(bdev, cmd);
+	if (error < 0)
+		return error;
+
 	/*
 	 * If we are in the middle of error recovery, don't let anyone
 	 * else try and use this device.  Also, if error recovery fails, it
@@ -1065,6 +1069,11 @@ static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
 			   unsigned int cmd, unsigned long arg)
 {
 	struct scsi_device *sdev = scsi_disk(bdev->bd_disk)->device;
+	int ret;
+
+	ret = scsi_verify_blk_ioctl(bdev, cmd);
+	if (ret < 0)
+		return ret;
 
 	/*
 	 * If we are in the middle of error recovery, don't let anyone
@@ -1076,8 +1085,6 @@ static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
 		return -ENODEV;
 	       
 	if (sdev->host->hostt->compat_ioctl) {
-		int ret;
-
 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
 
 		return ret;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index ba55e497f7dc..22713e8385f0 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -793,6 +793,7 @@ extern void blk_plug_device(struct request_queue *);
 extern void blk_plug_device_unlocked(struct request_queue *);
 extern int blk_remove_plug(struct request_queue *);
 extern void blk_recount_segments(struct request_queue *, struct bio *);
+extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
 extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
 			      unsigned int, void __user *);
 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
-- 
1.8.5.2