Evolution-X-Devices/kernel_google_msm-4.9
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block: silently forbid sending any ioctl to a partition

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After the first few months, the message has not led to many bug reports.
It's been almost five years now, and in practice the main source of
it seems to be MTIOCGET that someone is using to detect tape devices.
While we could whitelist it just like CDROM_GET_CAPABILITY, this patch
just removes the message altogether.

The patch also removes the "safe but not very useful" ioctl whitelist,
as suggested by Christoph.  I doubt anything is using most of those
ioctls _in general_, let alone on a partition.

Bug: 123627197
Change-Id: I24c634c29b635d8081cf1b9f00fa9dbb26b1aefe
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
This commit is contained in:
Paolo Bonzini
2018-01-10 16:54:52 +01:00
committed by Jaegeuk Kim
parent 6c91e1d0b8
commit f6a864744b
1 changed files with 0 additions and 29 deletions
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29
block/scsi_ioctl.c
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@@ -694,38 +694,9 @@ 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;
}
if (capable(CAP_SYS_RAWIO))
return 0;
/* 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 -ENOIOCTLCMD;
}
EXPORT_SYMBOL(scsi_verify_blk_ioctl);