OpenCloudOS-Kernel/block/scsi_ioctl.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2001 Jens Axboe <axboe@suse.de>
*/
#include <linux/compat.h>
#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>
#include <scsi/sg.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);
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);
/* ZBC Commands */
__set_bit(ZBC_OUT, filter->write_ok);
__set_bit(ZBC_IN, filter->read_ok);
}
int blk_verify_command(unsigned char *cmd, fmode_t mode)
{
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) && (mode & FMODE_WRITE))
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))
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 = req->result & 0xff;
hdr->masked_status = status_byte(req->result);
hdr->msg_status = COMMAND_COMPLETE;
hdr->host_status = host_byte(req->result);
hdr->driver_status = 0;
if (scsi_status_is_check_condition(hdr->status))
hdr->driver_status = DRIVER_SENSE;
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_DRV_OUT : REQ_OP_DRV_IN, 0);
if (IS_ERR(rq))
return PTR_ERR(rq);
req = scsi_req(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;
req->retries = 0;
start_time = jiffies;
blk_execute_rq(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
* @q: request queue to send scsi commands down
* @disk: gendisk to operate on (option)
* @mode: mode used to open the file through which the ioctl has been
* submitted
* @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.
*/
int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
struct scsi_ioctl_command __user *sic)
{
enum { OMAX_SB_LEN = 16 }; /* For backward compatibility */
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) {
buffer = kzalloc(bytes, GFP_NOIO | GFP_USER | __GFP_NOWARN);
if (!buffer)
return -ENOMEM;
}
rq = blk_get_request(q, in_len ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
if (IS_ERR(rq)) {
err = PTR_ERR(rq);
goto error_free_buffer;
}
req = scsi_req(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);
if (err)
goto error;
/* default. possible overriden later */
req->retries = 5;
switch (opcode) {
case SEND_DIAGNOSTIC:
case FORMAT_UNIT:
rq->timeout = FORMAT_UNIT_TIMEOUT;
req->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;
req->retries = 1;
break;
default:
rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
break;
}
if (bytes) {
err = blk_rq_map_kern(q, rq, buffer, bytes, GFP_NOIO);
if (err)
goto error;
}
blk_execute_rq(disk, rq, 0);
err = req->result & 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_DRV_OUT, 0);
if (IS_ERR(rq))
return PTR_ERR(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;
blk_execute_rq(bd_disk, rq, 0);
err = scsi_req(rq)->result ? -EIO : 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 put_sg_io_hdr(const struct sg_io_hdr *hdr, void __user *argp)
{
#ifdef CONFIG_COMPAT
if (in_compat_syscall()) {
struct compat_sg_io_hdr hdr32 = {
.interface_id = hdr->interface_id,
.dxfer_direction = hdr->dxfer_direction,
.cmd_len = hdr->cmd_len,
.mx_sb_len = hdr->mx_sb_len,
.iovec_count = hdr->iovec_count,
.dxfer_len = hdr->dxfer_len,
.dxferp = (uintptr_t)hdr->dxferp,
.cmdp = (uintptr_t)hdr->cmdp,
.sbp = (uintptr_t)hdr->sbp,
.timeout = hdr->timeout,
.flags = hdr->flags,
.pack_id = hdr->pack_id,
.usr_ptr = (uintptr_t)hdr->usr_ptr,
.status = hdr->status,
.masked_status = hdr->masked_status,
.msg_status = hdr->msg_status,
.sb_len_wr = hdr->sb_len_wr,
.host_status = hdr->host_status,
.driver_status = hdr->driver_status,
.resid = hdr->resid,
.duration = hdr->duration,
.info = hdr->info,
};
if (copy_to_user(argp, &hdr32, sizeof(hdr32)))
return -EFAULT;
return 0;
}
#endif
if (copy_to_user(argp, hdr, sizeof(*hdr)))
return -EFAULT;
return 0;
}
EXPORT_SYMBOL(put_sg_io_hdr);
int get_sg_io_hdr(struct sg_io_hdr *hdr, const void __user *argp)
{
#ifdef CONFIG_COMPAT
struct compat_sg_io_hdr hdr32;
if (in_compat_syscall()) {
if (copy_from_user(&hdr32, argp, sizeof(hdr32)))
return -EFAULT;
*hdr = (struct sg_io_hdr) {
.interface_id = hdr32.interface_id,
.dxfer_direction = hdr32.dxfer_direction,
.cmd_len = hdr32.cmd_len,
.mx_sb_len = hdr32.mx_sb_len,
.iovec_count = hdr32.iovec_count,
.dxfer_len = hdr32.dxfer_len,
.dxferp = compat_ptr(hdr32.dxferp),
.cmdp = compat_ptr(hdr32.cmdp),
.sbp = compat_ptr(hdr32.sbp),
.timeout = hdr32.timeout,
.flags = hdr32.flags,
.pack_id = hdr32.pack_id,
.usr_ptr = compat_ptr(hdr32.usr_ptr),
.status = hdr32.status,
.masked_status = hdr32.masked_status,
.msg_status = hdr32.msg_status,
.sb_len_wr = hdr32.sb_len_wr,
.host_status = hdr32.host_status,
.driver_status = hdr32.driver_status,
.resid = hdr32.resid,
.duration = hdr32.duration,
.info = hdr32.info,
};
return 0;
}
#endif
if (copy_from_user(hdr, argp, sizeof(*hdr)))
return -EFAULT;
return 0;
}
EXPORT_SYMBOL(get_sg_io_hdr);
#ifdef CONFIG_COMPAT
struct compat_cdrom_generic_command {
unsigned char cmd[CDROM_PACKET_SIZE];
compat_caddr_t buffer;
compat_uint_t buflen;
compat_int_t stat;
compat_caddr_t sense;
unsigned char data_direction;
unsigned char pad[3];
compat_int_t quiet;
compat_int_t timeout;
compat_caddr_t unused;
};
#endif
static int scsi_get_cdrom_generic_arg(struct cdrom_generic_command *cgc,
const void __user *arg)
{
#ifdef CONFIG_COMPAT
if (in_compat_syscall()) {
struct compat_cdrom_generic_command cgc32;
if (copy_from_user(&cgc32, arg, sizeof(cgc32)))
return -EFAULT;
*cgc = (struct cdrom_generic_command) {
.buffer = compat_ptr(cgc32.buffer),
.buflen = cgc32.buflen,
.stat = cgc32.stat,
.sense = compat_ptr(cgc32.sense),
.data_direction = cgc32.data_direction,
.quiet = cgc32.quiet,
.timeout = cgc32.timeout,
.unused = compat_ptr(cgc32.unused),
};
memcpy(&cgc->cmd, &cgc32.cmd, CDROM_PACKET_SIZE);
return 0;
}
#endif
if (copy_from_user(cgc, arg, sizeof(*cgc)))
return -EFAULT;
return 0;
}
static int scsi_put_cdrom_generic_arg(const struct cdrom_generic_command *cgc,
void __user *arg)
{
#ifdef CONFIG_COMPAT
if (in_compat_syscall()) {
struct compat_cdrom_generic_command cgc32 = {
.buffer = (uintptr_t)(cgc->buffer),
.buflen = cgc->buflen,
.stat = cgc->stat,
.sense = (uintptr_t)(cgc->sense),
.data_direction = cgc->data_direction,
.quiet = cgc->quiet,
.timeout = cgc->timeout,
.unused = (uintptr_t)(cgc->unused),
};
memcpy(&cgc32.cmd, &cgc->cmd, CDROM_PACKET_SIZE);
if (copy_to_user(arg, &cgc32, sizeof(cgc32)))
return -EFAULT;
return 0;
}
#endif
if (copy_to_user(arg, cgc, sizeof(*cgc)))
return -EFAULT;
return 0;
}
static int scsi_cdrom_send_packet(struct request_queue *q,
struct gendisk *bd_disk,
fmode_t mode, void __user *arg)
{
struct cdrom_generic_command cgc;
struct sg_io_hdr hdr;
int err;
err = scsi_get_cdrom_generic_arg(&cgc, arg);
if (err)
return err;
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;
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:
return -EINVAL;
}
hdr.dxferp = cgc.buffer;
hdr.sbp = cgc.sense;
if (hdr.sbp)
hdr.mx_sb_len = sizeof(struct request_sense);
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)
return -EFAULT;
if (hdr.status)
return -EIO;
cgc.stat = err;
cgc.buflen = hdr.resid;
if (scsi_put_cdrom_generic_arg(&cgc, arg))
return -EFAULT;
return err;
}
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 = get_sg_io_hdr(&hdr, arg);
if (err)
break;
err = sg_io(q, bd_disk, &hdr, mode);
if (err == -EFAULT)
break;
if (put_sg_io_hdr(&hdr, arg))
err = -EFAULT;
break;
}
case CDROM_SEND_PACKET:
err = scsi_cdrom_send_packet(q, bd_disk, mode, arg);
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 && !bdev_is_partition(bd))
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
return 0;
if (capable(CAP_SYS_RAWIO))
return 0;
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);
/**
* scsi_req_init - initialize certain fields of a scsi_request structure
* @req: Pointer to a scsi_request structure.
* Initializes .__cmd[], .cmd, .cmd_len and .sense_len but no other members
* of struct scsi_request.
*/
void scsi_req_init(struct scsi_request *req)
{
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);