linux/block/scsi_ioctl.c

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/*
* Copyright (C) 2001 Jens Axboe <axboe@suse.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
*
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public Licens
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
*
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/capability.h>
#include <linux/completion.h>
#include <linux/cdrom.h>
block: fail SCSI passthrough ioctls on partition devices 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>
2012-01-12 23:01:28 +08:00
#include <linux/ratelimit.h>
#include <linux/slab.h>
#include <linux/times.h>
#include <linux/uio.h>
#include <linux/uaccess.h>
#include <scsi/scsi.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/scsi_cmnd.h>
struct blk_cmd_filter {
unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
};
static struct blk_cmd_filter blk_default_cmd_filter;
/* Command group 3 is reserved and should never be used. */
const unsigned char scsi_command_size_tbl[8] =
{
6, 10, 10, 12,
16, 12, 10, 10
};
EXPORT_SYMBOL(scsi_command_size_tbl);
#include <scsi/sg.h>
static int sg_get_version(int __user *p)
{
static const int sg_version_num = 30527;
return put_user(sg_version_num, p);
}
static int scsi_get_idlun(struct request_queue *q, int __user *p)
{
return put_user(0, p);
}
static int scsi_get_bus(struct request_queue *q, int __user *p)
{
return put_user(0, p);
}
static int sg_get_timeout(struct request_queue *q)
{
return jiffies_to_clock_t(q->sg_timeout);
}
static int sg_set_timeout(struct request_queue *q, int __user *p)
{
int timeout, err = get_user(timeout, p);
if (!err)
q->sg_timeout = clock_t_to_jiffies(timeout);
return err;
}
static int max_sectors_bytes(struct request_queue *q)
{
unsigned int max_sectors = queue_max_sectors(q);
max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
return max_sectors << 9;
}
static int sg_get_reserved_size(struct request_queue *q, int __user *p)
{
int val = min_t(int, q->sg_reserved_size, max_sectors_bytes(q));
return put_user(val, p);
}
static int sg_set_reserved_size(struct request_queue *q, int __user *p)
{
int size, err = get_user(size, p);
if (err)
return err;
if (size < 0)
return -EINVAL;
q->sg_reserved_size = min(size, max_sectors_bytes(q));
return 0;
}
/*
* will always return that we are ATAPI even for a real SCSI drive, I'm not
* so sure this is worth doing anything about (why would you care??)
*/
static int sg_emulated_host(struct request_queue *q, int __user *p)
{
return put_user(1, p);
}
static void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter)
{
/* Basic read-only commands */
__set_bit(TEST_UNIT_READY, filter->read_ok);
__set_bit(REQUEST_SENSE, filter->read_ok);
__set_bit(READ_6, filter->read_ok);
__set_bit(READ_10, filter->read_ok);
__set_bit(READ_12, filter->read_ok);
__set_bit(READ_16, filter->read_ok);
__set_bit(READ_BUFFER, filter->read_ok);
__set_bit(READ_DEFECT_DATA, filter->read_ok);
__set_bit(READ_CAPACITY, filter->read_ok);
__set_bit(READ_LONG, filter->read_ok);
__set_bit(INQUIRY, filter->read_ok);
__set_bit(MODE_SENSE, filter->read_ok);
__set_bit(MODE_SENSE_10, filter->read_ok);
__set_bit(LOG_SENSE, filter->read_ok);
__set_bit(START_STOP, filter->read_ok);
__set_bit(GPCMD_VERIFY_10, filter->read_ok);
__set_bit(VERIFY_16, filter->read_ok);
__set_bit(REPORT_LUNS, filter->read_ok);
__set_bit(SERVICE_ACTION_IN_16, filter->read_ok);
__set_bit(RECEIVE_DIAGNOSTIC, filter->read_ok);
__set_bit(MAINTENANCE_IN, filter->read_ok);
__set_bit(GPCMD_READ_BUFFER_CAPACITY, filter->read_ok);
/* Audio CD commands */
__set_bit(GPCMD_PLAY_CD, filter->read_ok);
__set_bit(GPCMD_PLAY_AUDIO_10, filter->read_ok);
__set_bit(GPCMD_PLAY_AUDIO_MSF, filter->read_ok);
__set_bit(GPCMD_PLAY_AUDIO_TI, filter->read_ok);
__set_bit(GPCMD_PAUSE_RESUME, filter->read_ok);
/* CD/DVD data reading */
__set_bit(GPCMD_READ_CD, filter->read_ok);
__set_bit(GPCMD_READ_CD_MSF, filter->read_ok);
__set_bit(GPCMD_READ_DISC_INFO, filter->read_ok);
__set_bit(GPCMD_READ_CDVD_CAPACITY, filter->read_ok);
__set_bit(GPCMD_READ_DVD_STRUCTURE, filter->read_ok);
__set_bit(GPCMD_READ_HEADER, filter->read_ok);
__set_bit(GPCMD_READ_TRACK_RZONE_INFO, filter->read_ok);
__set_bit(GPCMD_READ_SUBCHANNEL, filter->read_ok);
__set_bit(GPCMD_READ_TOC_PMA_ATIP, filter->read_ok);
__set_bit(GPCMD_REPORT_KEY, filter->read_ok);
__set_bit(GPCMD_SCAN, filter->read_ok);
__set_bit(GPCMD_GET_CONFIGURATION, filter->read_ok);
__set_bit(GPCMD_READ_FORMAT_CAPACITIES, filter->read_ok);
__set_bit(GPCMD_GET_EVENT_STATUS_NOTIFICATION, filter->read_ok);
__set_bit(GPCMD_GET_PERFORMANCE, filter->read_ok);
__set_bit(GPCMD_SEEK, filter->read_ok);
__set_bit(GPCMD_STOP_PLAY_SCAN, filter->read_ok);
/* Basic writing commands */
__set_bit(WRITE_6, filter->write_ok);
__set_bit(WRITE_10, filter->write_ok);
__set_bit(WRITE_VERIFY, filter->write_ok);
__set_bit(WRITE_12, filter->write_ok);
__set_bit(WRITE_VERIFY_12, filter->write_ok);
__set_bit(WRITE_16, filter->write_ok);
__set_bit(WRITE_LONG, filter->write_ok);
__set_bit(WRITE_LONG_2, filter->write_ok);
block: allow WRITE_SAME commands with the SG_IO ioctl The WRITE_SAME commands are not present in the blk_default_cmd_filter write_ok list, and thus are failed with -EPERM when the SG_IO ioctl() is executed without CAP_SYS_RAWIO capability (e.g., unprivileged users). [ sg_io() -> blk_fill_sghdr_rq() > blk_verify_command() -> -EPERM ] The problem can be reproduced with the sg_write_same command # sg_write_same --num 1 --xferlen 512 /dev/sda # # capsh --drop=cap_sys_rawio -- -c \ 'sg_write_same --num 1 --xferlen 512 /dev/sda' Write same: pass through os error: Operation not permitted # For comparison, the WRITE_VERIFY command does not observe this problem, since it is in that list: # capsh --drop=cap_sys_rawio -- -c \ 'sg_write_verify --num 1 --ilen 512 --lba 0 /dev/sda' # So, this patch adds the WRITE_SAME commands to the list, in order for the SG_IO ioctl to finish successfully: # capsh --drop=cap_sys_rawio -- -c \ 'sg_write_same --num 1 --xferlen 512 /dev/sda' # That case happens to be exercised by QEMU KVM guests with 'scsi-block' devices (qemu "-device scsi-block" [1], libvirt "<disk type='block' device='lun'>" [2]), which employs the SG_IO ioctl() and runs as an unprivileged user (libvirt-qemu). In that scenario, when a filesystem (e.g., ext4) performs its zero-out calls, which are translated to write-same calls in the guest kernel, and then into SG_IO ioctls to the host kernel, SCSI I/O errors may be observed in the guest: [...] sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [...] sd 0:0:0:0: [sda] tag#0 Sense Key : Aborted Command [current] [...] sd 0:0:0:0: [sda] tag#0 Add. Sense: I/O process terminated [...] sd 0:0:0:0: [sda] tag#0 CDB: Write Same(10) 41 00 01 04 e0 78 00 00 08 00 [...] blk_update_request: I/O error, dev sda, sector 17096824 Links: [1] http://git.qemu.org/?p=qemu.git;a=commit;h=336a6915bc7089fb20fea4ba99972ad9a97c5f52 [2] https://libvirt.org/formatdomain.html#elementsDisks (see 'disk' -> 'device') Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Signed-off-by: Brahadambal Srinivasan <latha@linux.vnet.ibm.com> Reported-by: Manjunatha H R <manjuhr1@in.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-16 01:48:18 +08:00
__set_bit(WRITE_SAME, filter->write_ok);
__set_bit(WRITE_SAME_16, filter->write_ok);
__set_bit(WRITE_SAME_32, filter->write_ok);
__set_bit(ERASE, filter->write_ok);
__set_bit(GPCMD_MODE_SELECT_10, filter->write_ok);
__set_bit(MODE_SELECT, filter->write_ok);
__set_bit(LOG_SELECT, filter->write_ok);
__set_bit(GPCMD_BLANK, filter->write_ok);
__set_bit(GPCMD_CLOSE_TRACK, filter->write_ok);
__set_bit(GPCMD_FLUSH_CACHE, filter->write_ok);
__set_bit(GPCMD_FORMAT_UNIT, filter->write_ok);
__set_bit(GPCMD_REPAIR_RZONE_TRACK, filter->write_ok);
__set_bit(GPCMD_RESERVE_RZONE_TRACK, filter->write_ok);
__set_bit(GPCMD_SEND_DVD_STRUCTURE, filter->write_ok);
__set_bit(GPCMD_SEND_EVENT, filter->write_ok);
__set_bit(GPCMD_SEND_KEY, filter->write_ok);
__set_bit(GPCMD_SEND_OPC, filter->write_ok);
__set_bit(GPCMD_SEND_CUE_SHEET, filter->write_ok);
__set_bit(GPCMD_SET_SPEED, filter->write_ok);
__set_bit(GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL, filter->write_ok);
__set_bit(GPCMD_LOAD_UNLOAD, filter->write_ok);
__set_bit(GPCMD_SET_STREAMING, filter->write_ok);
__set_bit(GPCMD_SET_READ_AHEAD, filter->write_ok);
}
int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm)
{
struct blk_cmd_filter *filter = &blk_default_cmd_filter;
/* root can do any command. */
if (capable(CAP_SYS_RAWIO))
return 0;
/* Anybody who can open the device can do a read-safe command */
if (test_bit(cmd[0], filter->read_ok))
return 0;
/* Write-safe commands require a writable open */
if (test_bit(cmd[0], filter->write_ok) && has_write_perm)
return 0;
return -EPERM;
}
EXPORT_SYMBOL(blk_verify_command);
static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq,
struct sg_io_hdr *hdr, fmode_t mode)
{
struct scsi_request *req = scsi_req(rq);
if (copy_from_user(req->cmd, hdr->cmdp, hdr->cmd_len))
return -EFAULT;
if (blk_verify_command(req->cmd, mode & FMODE_WRITE))
return -EPERM;
/*
* fill in request structure
*/
req->cmd_len = hdr->cmd_len;
rq->timeout = msecs_to_jiffies(hdr->timeout);
if (!rq->timeout)
rq->timeout = q->sg_timeout;
if (!rq->timeout)
rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
if (rq->timeout < BLK_MIN_SG_TIMEOUT)
rq->timeout = BLK_MIN_SG_TIMEOUT;
return 0;
}
static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
struct bio *bio)
{
struct scsi_request *req = scsi_req(rq);
int r, ret = 0;
/*
* fill in all the output members
*/
hdr->status = rq->errors & 0xff;
hdr->masked_status = status_byte(rq->errors);
hdr->msg_status = msg_byte(rq->errors);
hdr->host_status = host_byte(rq->errors);
hdr->driver_status = driver_byte(rq->errors);
hdr->info = 0;
if (hdr->masked_status || hdr->host_status || hdr->driver_status)
hdr->info |= SG_INFO_CHECK;
hdr->resid = req->resid_len;
hdr->sb_len_wr = 0;
if (req->sense_len && hdr->sbp) {
int len = min((unsigned int) hdr->mx_sb_len, req->sense_len);
if (!copy_to_user(hdr->sbp, req->sense, len))
hdr->sb_len_wr = len;
else
ret = -EFAULT;
}
r = blk_rq_unmap_user(bio);
if (!ret)
ret = r;
return ret;
}
static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
struct sg_io_hdr *hdr, fmode_t mode)
{
unsigned long start_time;
ssize_t ret = 0;
int writing = 0;
int at_head = 0;
struct request *rq;
struct scsi_request *req;
struct bio *bio;
if (hdr->interface_id != 'S')
return -EINVAL;
if (hdr->dxfer_len > (queue_max_hw_sectors(q) << 9))
return -EIO;
if (hdr->dxfer_len)
switch (hdr->dxfer_direction) {
default:
return -EINVAL;
case SG_DXFER_TO_DEV:
writing = 1;
break;
case SG_DXFER_TO_FROM_DEV:
case SG_DXFER_FROM_DEV:
break;
}
if (hdr->flags & SG_FLAG_Q_AT_HEAD)
at_head = 1;
ret = -ENOMEM;
rq = blk_get_request(q, writing ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
GFP_KERNEL);
if (IS_ERR(rq))
return PTR_ERR(rq);
req = scsi_req(rq);
scsi_req_init(rq);
if (hdr->cmd_len > BLK_MAX_CDB) {
req->cmd = kzalloc(hdr->cmd_len, GFP_KERNEL);
if (!req->cmd)
goto out_put_request;
}
ret = blk_fill_sghdr_rq(q, rq, hdr, mode);
if (ret < 0)
goto out_free_cdb;
ret = 0;
if (hdr->iovec_count) {
struct iov_iter i;
struct iovec *iov = NULL;
ret = import_iovec(rq_data_dir(rq),
hdr->dxferp, hdr->iovec_count,
0, &iov, &i);
if (ret < 0)
goto out_free_cdb;
/* SG_IO howto says that the shorter of the two wins */
iov_iter_truncate(&i, hdr->dxfer_len);
ret = blk_rq_map_user_iov(q, rq, NULL, &i, GFP_KERNEL);
kfree(iov);
} else if (hdr->dxfer_len)
ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len,
GFP_KERNEL);
if (ret)
goto out_free_cdb;
bio = rq->bio;
rq->retries = 0;
start_time = jiffies;
/* ignore return value. All information is passed back to caller
* (if he doesn't check that is his problem).
* N.B. a non-zero SCSI status is _not_ necessarily an error.
*/
blk_execute_rq(q, bd_disk, rq, at_head);
hdr->duration = jiffies_to_msecs(jiffies - start_time);
ret = blk_complete_sghdr_rq(rq, hdr, bio);
out_free_cdb:
scsi_req_free_cmd(req);
out_put_request:
blk_put_request(rq);
return ret;
}
/**
* sg_scsi_ioctl -- handle deprecated SCSI_IOCTL_SEND_COMMAND ioctl
* @file: file this ioctl operates on (optional)
* @q: request queue to send scsi commands down
* @disk: gendisk to operate on (option)
* @sic: userspace structure describing the command to perform
*
* Send down the scsi command described by @sic to the device below
* the request queue @q. If @file is non-NULL it's used to perform
* fine-grained permission checks that allow users to send down
* non-destructive SCSI commands. If the caller has a struct gendisk
* available it should be passed in as @disk to allow the low level
* driver to use the information contained in it. A non-NULL @disk
* is only allowed if the caller knows that the low level driver doesn't
* need it (e.g. in the scsi subsystem).
*
* Notes:
* - This interface is deprecated - users should use the SG_IO
* interface instead, as this is a more flexible approach to
* performing SCSI commands on a device.
* - The SCSI command length is determined by examining the 1st byte
* of the given command. There is no way to override this.
* - Data transfers are limited to PAGE_SIZE
* - The length (x + y) must be at least OMAX_SB_LEN bytes long to
* accommodate the sense buffer when an error occurs.
* The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
* old code will not be surprised.
* - If a Unix error occurs (e.g. ENOMEM) then the user will receive
* a negative return and the Unix error code in 'errno'.
* If the SCSI command succeeds then 0 is returned.
* Positive numbers returned are the compacted SCSI error codes (4
* bytes in one int) where the lowest byte is the SCSI status.
*/
#define OMAX_SB_LEN 16 /* For backward compatibility */
int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
struct scsi_ioctl_command __user *sic)
{
struct request *rq;
struct scsi_request *req;
int err;
unsigned int in_len, out_len, bytes, opcode, cmdlen;
char *buffer = NULL;
if (!sic)
return -EINVAL;
/*
* get in an out lengths, verify they don't exceed a page worth of data
*/
if (get_user(in_len, &sic->inlen))
return -EFAULT;
if (get_user(out_len, &sic->outlen))
return -EFAULT;
if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
return -EINVAL;
if (get_user(opcode, sic->data))
return -EFAULT;
bytes = max(in_len, out_len);
if (bytes) {
2007-07-19 16:49:03 +08:00
buffer = kzalloc(bytes, q->bounce_gfp | GFP_USER| __GFP_NOWARN);
if (!buffer)
return -ENOMEM;
}
rq = blk_get_request(q, in_len ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
__GFP_RECLAIM);
if (IS_ERR(rq)) {
err = PTR_ERR(rq);
goto error_free_buffer;
}
req = scsi_req(rq);
scsi_req_init(rq);
cmdlen = COMMAND_SIZE(opcode);
/*
* get command and data to send to device, if any
*/
err = -EFAULT;
req->cmd_len = cmdlen;
if (copy_from_user(req->cmd, sic->data, cmdlen))
goto error;
if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
goto error;
err = blk_verify_command(req->cmd, mode & FMODE_WRITE);
if (err)
goto error;
/* default. possible overriden later */
rq->retries = 5;
switch (opcode) {
case SEND_DIAGNOSTIC:
case FORMAT_UNIT:
rq->timeout = FORMAT_UNIT_TIMEOUT;
rq->retries = 1;
break;
case START_STOP:
rq->timeout = START_STOP_TIMEOUT;
break;
case MOVE_MEDIUM:
rq->timeout = MOVE_MEDIUM_TIMEOUT;
break;
case READ_ELEMENT_STATUS:
rq->timeout = READ_ELEMENT_STATUS_TIMEOUT;
break;
case READ_DEFECT_DATA:
rq->timeout = READ_DEFECT_DATA_TIMEOUT;
rq->retries = 1;
break;
default:
rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
break;
}
if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, __GFP_RECLAIM)) {
err = DRIVER_ERROR << 24;
goto error;
}
blk_execute_rq(q, disk, rq, 0);
err = rq->errors & 0xff; /* only 8 bit SCSI status */
if (err) {
if (req->sense_len && req->sense) {
bytes = (OMAX_SB_LEN > req->sense_len) ?
req->sense_len : OMAX_SB_LEN;
if (copy_to_user(sic->data, req->sense, bytes))
err = -EFAULT;
}
} else {
if (copy_to_user(sic->data, buffer, out_len))
err = -EFAULT;
}
error:
blk_put_request(rq);
error_free_buffer:
kfree(buffer);
return err;
}
EXPORT_SYMBOL_GPL(sg_scsi_ioctl);
/* Send basic block requests */
static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
int cmd, int data)
{
struct request *rq;
int err;
rq = blk_get_request(q, REQ_OP_SCSI_OUT, __GFP_RECLAIM);
if (IS_ERR(rq))
return PTR_ERR(rq);
scsi_req_init(rq);
rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
scsi_req(rq)->cmd[0] = cmd;
scsi_req(rq)->cmd[4] = data;
scsi_req(rq)->cmd_len = 6;
err = blk_execute_rq(q, bd_disk, rq, 0);
blk_put_request(rq);
return err;
}
static inline int blk_send_start_stop(struct request_queue *q,
struct gendisk *bd_disk, int data)
{
return __blk_send_generic(q, bd_disk, GPCMD_START_STOP_UNIT, data);
}
int scsi_cmd_ioctl(struct request_queue *q, struct gendisk *bd_disk, fmode_t mode,
unsigned int cmd, void __user *arg)
{
int err;
if (!q)
return -ENXIO;
switch (cmd) {
/*
* new sgv3 interface
*/
case SG_GET_VERSION_NUM:
err = sg_get_version(arg);
break;
case SCSI_IOCTL_GET_IDLUN:
err = scsi_get_idlun(q, arg);
break;
case SCSI_IOCTL_GET_BUS_NUMBER:
err = scsi_get_bus(q, arg);
break;
case SG_SET_TIMEOUT:
err = sg_set_timeout(q, arg);
break;
case SG_GET_TIMEOUT:
err = sg_get_timeout(q);
break;
case SG_GET_RESERVED_SIZE:
err = sg_get_reserved_size(q, arg);
break;
case SG_SET_RESERVED_SIZE:
err = sg_set_reserved_size(q, arg);
break;
case SG_EMULATED_HOST:
err = sg_emulated_host(q, arg);
break;
case SG_IO: {
struct sg_io_hdr hdr;
err = -EFAULT;
if (copy_from_user(&hdr, arg, sizeof(hdr)))
break;
err = sg_io(q, bd_disk, &hdr, mode);
if (err == -EFAULT)
break;
if (copy_to_user(arg, &hdr, sizeof(hdr)))
err = -EFAULT;
break;
}
case CDROM_SEND_PACKET: {
struct cdrom_generic_command cgc;
struct sg_io_hdr hdr;
err = -EFAULT;
if (copy_from_user(&cgc, arg, sizeof(cgc)))
break;
cgc.timeout = clock_t_to_jiffies(cgc.timeout);
memset(&hdr, 0, sizeof(hdr));
hdr.interface_id = 'S';
hdr.cmd_len = sizeof(cgc.cmd);
hdr.dxfer_len = cgc.buflen;
err = 0;
switch (cgc.data_direction) {
case CGC_DATA_UNKNOWN:
hdr.dxfer_direction = SG_DXFER_UNKNOWN;
break;
case CGC_DATA_WRITE:
hdr.dxfer_direction = SG_DXFER_TO_DEV;
break;
case CGC_DATA_READ:
hdr.dxfer_direction = SG_DXFER_FROM_DEV;
break;
case CGC_DATA_NONE:
hdr.dxfer_direction = SG_DXFER_NONE;
break;
default:
err = -EINVAL;
}
if (err)
break;
hdr.dxferp = cgc.buffer;
hdr.sbp = cgc.sense;
if (hdr.sbp)
hdr.mx_sb_len = sizeof(struct request_sense);
[SCSI] block: Fix miscalculation of sg_io timeout in CDROM_SEND_PACKET handler. It seems cdrwtool in the udftools has been unusable on "modern" kernels for some time. A Google search reveals many people with the same issue but no solution (cdrwtool fails to format the disk). After spending some time tracking down the issue, it comes down to the following: The udftools still use the older CDROM_SEND_PACKET interface to send things like FORMAT_UNIT through to the drive. They should really be updated, but that's another story. Since most distros are using libata now, the cd or dvd burner appears as a SCSI device, and we wind up in block/scsi_ioctl.c. Here, the code tries to take the "struct cdrom_generic_command" and translate it and stuff it into a "struct sg_io_hdr" structure so it can pass it to the modern sg_io() routine instead. Unfortunately, there is one error, or rather an omission in the translation. The timeout that is passed in in the "struct cdrom_generic_command" is in HZ=100 units, and this is modified and correctly converted to jiffies by use of clock_t_to_jiffies(). However, a little further down, this cgc.timeout value in jiffies is simply copied into the sg_io_hdr timeout, which should be in milliseconds. Since most modern x86 kernels seems to be getting build with HZ=250, the timeout that is passed to sg_io and eventually converted to the timeout_per_command member of the scsi_cmnd structure is now four times too small. Since cdrwtool tries to set the timeout to one hour for the FORMAT_UNIT command, and it takes about 20 minutes to format a 4x CDRW, the SCSI error-handler kicks in after the FORMAT_UNIT completes because it took longer than the incorrectly-calculated timeout. [jejb: fix up whitespace] Signed-off-by: Tim Wright <timw@splhi.com> Cc: Stable Tree <stable@kernel.org> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-28 08:50:38 +08:00
hdr.timeout = jiffies_to_msecs(cgc.timeout);
hdr.cmdp = ((struct cdrom_generic_command __user*) arg)->cmd;
hdr.cmd_len = sizeof(cgc.cmd);
err = sg_io(q, bd_disk, &hdr, mode);
if (err == -EFAULT)
break;
if (hdr.status)
err = -EIO;
cgc.stat = err;
cgc.buflen = hdr.resid;
if (copy_to_user(arg, &cgc, sizeof(cgc)))
err = -EFAULT;
break;
}
/*
* old junk scsi send command ioctl
*/
case SCSI_IOCTL_SEND_COMMAND:
printk(KERN_WARNING "program %s is using a deprecated SCSI ioctl, please convert it to SG_IO\n", current->comm);
err = -EINVAL;
if (!arg)
break;
err = sg_scsi_ioctl(q, bd_disk, mode, arg);
break;
case CDROMCLOSETRAY:
err = blk_send_start_stop(q, bd_disk, 0x03);
break;
case CDROMEJECT:
err = blk_send_start_stop(q, bd_disk, 0x02);
break;
default:
err = -ENOTTY;
}
return err;
}
EXPORT_SYMBOL(scsi_cmd_ioctl);
block: fail SCSI passthrough ioctls on partition devices 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>
2012-01-12 23:01:28 +08:00
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;
block: fail SCSI passthrough ioctls on partition devices 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>
2012-01-12 23:01:28 +08:00
/* 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;
block: fail SCSI passthrough ioctls on partition devices 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>
2012-01-12 23:01:28 +08:00
}
EXPORT_SYMBOL(scsi_verify_blk_ioctl);
int scsi_cmd_blk_ioctl(struct block_device *bd, fmode_t mode,
unsigned int cmd, void __user *arg)
{
block: fail SCSI passthrough ioctls on partition devices 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>
2012-01-12 23:01:28 +08:00
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);
void scsi_req_init(struct request *rq)
{
struct scsi_request *req = scsi_req(rq);
memset(req->__cmd, 0, sizeof(req->__cmd));
req->cmd = req->__cmd;
req->cmd_len = BLK_MAX_CDB;
req->sense_len = 0;
}
EXPORT_SYMBOL(scsi_req_init);
static int __init blk_scsi_ioctl_init(void)
{
blk_set_cmd_filter_defaults(&blk_default_cmd_filter);
return 0;
}
fs_initcall(blk_scsi_ioctl_init);