Commit message: scsi: sg: add sg_remove_request in sg_write

If the __copy_from_user function failed we need to call sg_remove_request
in sg_write.

Link: https://lore.kernel.org/r/610618d9-e983-fd56-ed0f-639428343af7@huawei.com
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Wu Bo <wubo40@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
CVE: CVE-2020-12770
CWE: NVD-CWE-noinfo
Vulnerability description: An issue was discovered in the Linux kernel through 5.6.11. sg_write lacks an sg_remove_request call in a certain failure case, aka CID-83c6f2390040.

Project: linux
File: sg.c

sg_proc_init(void)
{
	struct proc_dir_entry *p;

	p = proc_mkdir("scsi/sg", NULL);
	if (!p)
		return 1;

	proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_proc_ops);
	proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
	proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_proc_ops);
	proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
	proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
	proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
	proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
	return 0;
}

Project: linux
File: sg.c

sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
		 size_t count, int blocking, int read_only, int sg_io_owned,
		 Sg_request **o_srp)
{
	int k;
	Sg_request *srp;
	sg_io_hdr_t *hp;
	unsigned char cmnd[SG_MAX_CDB_SIZE];
	int timeout;
	unsigned long ul_timeout;

	if (count < SZ_SG_IO_HDR)
		return -EINVAL;

	sfp->cmd_q = 1;	/* when sg_io_hdr seen, set command queuing on */
	if (!(srp = sg_add_request(sfp))) {
		SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
					      "sg_new_write: queue full\n"));
		return -EDOM;
	}
	srp->sg_io_owned = sg_io_owned;
	hp = &srp->header;
	if (get_sg_io_hdr(hp, buf)) {
		sg_remove_request(sfp, srp);
		return -EFAULT;
	}
	if (hp->interface_id != 'S') {
		sg_remove_request(sfp, srp);
		return -ENOSYS;
	}
	if (hp->flags & SG_FLAG_MMAP_IO) {
		if (hp->dxfer_len > sfp->reserve.bufflen) {
			sg_remove_request(sfp, srp);
			return -ENOMEM;	/* MMAP_IO size must fit in reserve buffer */
		}
		if (hp->flags & SG_FLAG_DIRECT_IO) {
			sg_remove_request(sfp, srp);
			return -EINVAL;	/* either MMAP_IO or DIRECT_IO (not both) */
		}
		if (sfp->res_in_use) {
			sg_remove_request(sfp, srp);
			return -EBUSY;	/* reserve buffer already being used */
		}
	}
	ul_timeout = msecs_to_jiffies(srp->header.timeout);
	timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
	if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
		sg_remove_request(sfp, srp);
		return -EMSGSIZE;
	}
	if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
		sg_remove_request(sfp, srp);
		return -EFAULT;
	}
	if (read_only && sg_allow_access(file, cmnd)) {
		sg_remove_request(sfp, srp);
		return -EPERM;
	}
	k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
	if (k < 0)
		return k;
	if (o_srp)
		*o_srp = srp;
	return count;
}

Project: linux
File: sg.c

sg_rq_end_io(struct request *rq, blk_status_t status)
{
	struct sg_request *srp = rq->end_io_data;
	struct scsi_request *req = scsi_req(rq);
	Sg_device *sdp;
	Sg_fd *sfp;
	unsigned long iflags;
	unsigned int ms;
	char *sense;
	int result, resid, done = 1;

	if (WARN_ON(srp->done != 0))
		return;

	sfp = srp->parentfp;
	if (WARN_ON(sfp == NULL))
		return;

	sdp = sfp->parentdp;
	if (unlikely(atomic_read(&sdp->detaching)))
		pr_info("%s: device detaching\n", __func__);

	sense = req->sense;
	result = req->result;
	resid = req->resid_len;

	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
				      "sg_cmd_done: pack_id=%d, res=0x%x\n",
				      srp->header.pack_id, result));
	srp->header.resid = resid;
	ms = jiffies_to_msecs(jiffies);
	srp->header.duration = (ms > srp->header.duration) ?
				(ms - srp->header.duration) : 0;
	if (0 != result) {
		struct scsi_sense_hdr sshdr;

		srp->header.status = 0xff & result;
		srp->header.masked_status = status_byte(result);
		srp->header.msg_status = msg_byte(result);
		srp->header.host_status = host_byte(result);
		srp->header.driver_status = driver_byte(result);
		if ((sdp->sgdebug > 0) &&
		    ((CHECK_CONDITION == srp->header.masked_status) ||
		     (COMMAND_TERMINATED == srp->header.masked_status)))
			__scsi_print_sense(sdp->device, __func__, sense,
					   SCSI_SENSE_BUFFERSIZE);

		/* Following if statement is a patch supplied by Eric Youngdale */
		if (driver_byte(result) != 0
		    && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
		    && !scsi_sense_is_deferred(&sshdr)
		    && sshdr.sense_key == UNIT_ATTENTION
		    && sdp->device->removable) {
			/* Detected possible disc change. Set the bit - this */
			/* may be used if there are filesystems using this device */
			sdp->device->changed = 1;
		}
	}

	if (req->sense_len)
		memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);

	/* Rely on write phase to clean out srp status values, so no "else" */

	/*
	 * Free the request as soon as it is complete so that its resources
	 * can be reused without waiting for userspace to read() the
	 * result.  But keep the associated bio (if any) around until
	 * blk_rq_unmap_user() can be called from user context.
	 */
	srp->rq = NULL;
	scsi_req_free_cmd(scsi_req(rq));
	blk_put_request(rq);

	write_lock_irqsave(&sfp->rq_list_lock, iflags);
	if (unlikely(srp->orphan)) {
		if (sfp->keep_orphan)
			srp->sg_io_owned = 0;
		else
			done = 0;
	}
	srp->done = done;
	write_unlock_irqrestore(&sfp->rq_list_lock, iflags);

	if (likely(done)) {
		/* Now wake up any sg_read() that is waiting for this
		 * packet.
		 */
		wake_up_interruptible(&sfp->read_wait);
		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
		kref_put(&sfp->f_ref, sg_remove_sfp);
	} else {
		INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
		schedule_work(&srp->ew.work);
	}
}

Project: linux
File: sg.c

static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
	void __user *p = compat_ptr(arg);
	Sg_device *sdp;
	Sg_fd *sfp;
	int ret;

	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
		return -ENXIO;

	ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
	if (ret != -ENOIOCTLCMD)
		return ret;

	return scsi_compat_ioctl(sdp->device, cmd_in, p);
}

Project: linux
File: sg.c

sg_add_sfp(Sg_device * sdp)
{
	Sg_fd *sfp;
	unsigned long iflags;
	int bufflen;

	sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
	if (!sfp)
		return ERR_PTR(-ENOMEM);

	init_waitqueue_head(&sfp->read_wait);
	rwlock_init(&sfp->rq_list_lock);
	INIT_LIST_HEAD(&sfp->rq_list);
	kref_init(&sfp->f_ref);
	mutex_init(&sfp->f_mutex);
	sfp->timeout = SG_DEFAULT_TIMEOUT;
	sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
	sfp->force_packid = SG_DEF_FORCE_PACK_ID;
	sfp->cmd_q = SG_DEF_COMMAND_Q;
	sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
	sfp->parentdp = sdp;
	write_lock_irqsave(&sdp->sfd_lock, iflags);
	if (atomic_read(&sdp->detaching)) {
		write_unlock_irqrestore(&sdp->sfd_lock, iflags);
		kfree(sfp);
		return ERR_PTR(-ENODEV);
	}
	list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
	write_unlock_irqrestore(&sdp->sfd_lock, iflags);
	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
				      "sg_add_sfp: sfp=0x%p\n", sfp));
	if (unlikely(sg_big_buff != def_reserved_size))
		sg_big_buff = def_reserved_size;

	bufflen = min_t(int, sg_big_buff,
			max_sectors_bytes(sdp->device->request_queue));
	sg_build_reserve(sfp, bufflen);
	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
				      "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
				      sfp->reserve.bufflen,
				      sfp->reserve.k_use_sg));

	kref_get(&sdp->d_ref);
	__module_get(THIS_MODULE);
	return sfp;
}

Project: linux
File: sg.c

sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
{
	int mxsize, cmd_size, k;
	int input_size, blocking;
	unsigned char opcode;
	Sg_device *sdp;
	Sg_fd *sfp;
	Sg_request *srp;
	struct sg_header old_hdr;
	sg_io_hdr_t *hp;
	unsigned char cmnd[SG_MAX_CDB_SIZE];
	int retval;

	retval = sg_check_file_access(filp, __func__);
	if (retval)
		return retval;

	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
		return -ENXIO;
	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
				      "sg_write: count=%d\n", (int) count));
	if (atomic_read(&sdp->detaching))
		return -ENODEV;
	if (!((filp->f_flags & O_NONBLOCK) ||
	      scsi_block_when_processing_errors(sdp->device)))
		return -ENXIO;

	if (count < SZ_SG_HEADER)
		return -EIO;
	if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
		return -EFAULT;
	blocking = !(filp->f_flags & O_NONBLOCK);
	if (old_hdr.reply_len < 0)
		return sg_new_write(sfp, filp, buf, count,
				    blocking, 0, 0, NULL);
	if (count < (SZ_SG_HEADER + 6))
		return -EIO;	/* The minimum scsi command length is 6 bytes. */

	buf += SZ_SG_HEADER;
	if (get_user(opcode, buf))
		return -EFAULT;

	if (!(srp = sg_add_request(sfp))) {
		SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
					      "sg_write: queue full\n"));
		return -EDOM;
	}
	mutex_lock(&sfp->f_mutex);
	if (sfp->next_cmd_len > 0) {
		cmd_size = sfp->next_cmd_len;
		sfp->next_cmd_len = 0;	/* reset so only this write() effected */
	} else {
		cmd_size = COMMAND_SIZE(opcode);	/* based on SCSI command group */
		if ((opcode >= 0xc0) && old_hdr.twelve_byte)
			cmd_size = 12;
	}
	mutex_unlock(&sfp->f_mutex);
	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
		"sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
/* Determine buffer size.  */
	input_size = count - cmd_size;
	mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
	mxsize -= SZ_SG_HEADER;
	input_size -= SZ_SG_HEADER;
	if (input_size < 0) {
		sg_remove_request(sfp, srp);
		return -EIO;	/* User did not pass enough bytes for this command. */
	}
	hp = &srp->header;
	hp->interface_id = '\0';	/* indicator of old interface tunnelled */
	hp->cmd_len = (unsigned char) cmd_size;
	hp->iovec_count = 0;
	hp->mx_sb_len = 0;
	if (input_size > 0)
		hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
		    SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
	else
		hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
	hp->dxfer_len = mxsize;
	if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
	    (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
		hp->dxferp = (char __user *)buf + cmd_size;
	else
		hp->dxferp = NULL;
	hp->sbp = NULL;
	hp->timeout = old_hdr.reply_len;	/* structure abuse ... */
	hp->flags = input_size;	/* structure abuse ... */
	hp->pack_id = old_hdr.pack_id;
	hp->usr_ptr = NULL;
	if (copy_from_user(cmnd, buf, cmd_size)) {
		sg_remove_request(sfp, srp);
		return -EFAULT;
	}
	/*
	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
	 * is a non-zero input_size, so emit a warning.
	 */
	if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
		printk_ratelimited(KERN_WARNING
				   "sg_write: data in/out %d/%d bytes "
				   "for SCSI command 0x%x-- guessing "
				   "data in;\n   program %s not setting "
				   "count and/or reply_len properly\n",
				   old_hdr.reply_len - (int)SZ_SG_HEADER,
				   input_size, (unsigned int) cmnd[0],
				   current->comm);
	}
	k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
	return (k < 0) ? k : count;
}

Project: linux
File: sg.c

sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
{
	Sg_device *sdp;
	Sg_fd *sfp;
	Sg_request *srp;
	int req_pack_id = -1;
	sg_io_hdr_t *hp;
	struct sg_header *old_hdr;
	int retval;

	/*
	 * This could cause a response to be stranded. Close the associated
	 * file descriptor to free up any resources being held.
	 */
	retval = sg_check_file_access(filp, __func__);
	if (retval)
		return retval;

	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
		return -ENXIO;
	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
				      "sg_read: count=%d\n", (int) count));

	if (sfp->force_packid)
		retval = get_sg_io_pack_id(&req_pack_id, buf, count);
	if (retval)
		return retval;

	srp = sg_get_rq_mark(sfp, req_pack_id);
	if (!srp) {		/* now wait on packet to arrive */
		if (atomic_read(&sdp->detaching))
			return -ENODEV;
		if (filp->f_flags & O_NONBLOCK)
			return -EAGAIN;
		retval = wait_event_interruptible(sfp->read_wait,
			(atomic_read(&sdp->detaching) ||
			(srp = sg_get_rq_mark(sfp, req_pack_id))));
		if (atomic_read(&sdp->detaching))
			return -ENODEV;
		if (retval)
			/* -ERESTARTSYS as signal hit process */
			return retval;
	}
	if (srp->header.interface_id != '\0')
		return sg_new_read(sfp, buf, count, srp);

	hp = &srp->header;
	old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
	if (!old_hdr)
		return -ENOMEM;

	old_hdr->reply_len = (int) hp->timeout;
	old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
	old_hdr->pack_id = hp->pack_id;
	old_hdr->twelve_byte =
	    ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
	old_hdr->target_status = hp->masked_status;
	old_hdr->host_status = hp->host_status;
	old_hdr->driver_status = hp->driver_status;
	if ((CHECK_CONDITION & hp->masked_status) ||
	    (DRIVER_SENSE & hp->driver_status))
		memcpy(old_hdr->sense_buffer, srp->sense_b,
		       sizeof (old_hdr->sense_buffer));
	switch (hp->host_status) {
	/* This setup of 'result' is for backward compatibility and is best
	   ignored by the user who should use target, host + driver status */
	case DID_OK:
	case DID_PASSTHROUGH:
	case DID_SOFT_ERROR:
		old_hdr->result = 0;
		break;
	case DID_NO_CONNECT:
	case DID_BUS_BUSY:
	case DID_TIME_OUT:
		old_hdr->result = EBUSY;
		break;
	case DID_BAD_TARGET:
	case DID_ABORT:
	case DID_PARITY:
	case DID_RESET:
	case DID_BAD_INTR:
		old_hdr->result = EIO;
		break;
	case DID_ERROR:
		old_hdr->result = (srp->sense_b[0] == 0 && 
				  hp->masked_status == GOOD) ? 0 : EIO;
		break;
	default:
		old_hdr->result = EIO;
		break;
	}

	/* Now copy the result back to the user buffer.  */
	if (count >= SZ_SG_HEADER) {
		if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
			retval = -EFAULT;
			goto free_old_hdr;
		}
		buf += SZ_SG_HEADER;
		if (count > old_hdr->reply_len)
			count = old_hdr->reply_len;
		if (count > SZ_SG_HEADER) {
			if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
				retval = -EFAULT;
				goto free_old_hdr;
			}
		}
	} else
		count = (old_hdr->result == 0) ? 0 : -EIO;
	sg_finish_rem_req(srp);
	sg_remove_request(sfp, srp);
	retval = count;
free_old_hdr:
	kfree(old_hdr);
	return retval;
}

Project: linux
File: sg.c

sg_device_destroy(struct kref *kref)
{
	struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
	unsigned long flags;

	/* CAUTION!  Note that the device can still be found via idr_find()
	 * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
	 * any other cleanup.
	 */

	write_lock_irqsave(&sg_index_lock, flags);
	idr_remove(&sg_index_idr, sdp->index);
	write_unlock_irqrestore(&sg_index_lock, flags);

	SCSI_LOG_TIMEOUT(3,
		sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));

	put_disk(sdp->disk);
	kfree(sdp);
}

Project: linux
File: sg.c

exit_sg(void)
{
#ifdef CONFIG_SCSI_PROC_FS
	remove_proc_subtree("scsi/sg", NULL);
#endif				/* CONFIG_SCSI_PROC_FS */
	scsi_unregister_interface(&sg_interface);
	class_destroy(sg_sysfs_class);
	sg_sysfs_valid = 0;
	unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
				 SG_MAX_DEVS);
	idr_destroy(&sg_index_idr);
}

Project: linux
File: sg.c

sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
		unsigned int cmd_in, void __user *p)
{
	int __user *ip = p;
	int result, val, read_only;
	Sg_request *srp;
	unsigned long iflags;

	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
				   "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));

	switch (cmd_in) {
	case SG_IO:
		if (atomic_read(&sdp->detaching))
			return -ENODEV;
		if (!scsi_block_when_processing_errors(sdp->device))
			return -ENXIO;
		result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
				 1, read_only, 1, &srp);
		if (result < 0)
			return result;
		result = wait_event_interruptible(sfp->read_wait,
			(srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
		if (atomic_read(&sdp->detaching))
			return -ENODEV;
		write_lock_irq(&sfp->rq_list_lock);
		if (srp->done) {
			srp->done = 2;
			write_unlock_irq(&sfp->rq_list_lock);
			result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
			return (result < 0) ? result : 0;
		}
		srp->orphan = 1;
		write_unlock_irq(&sfp->rq_list_lock);
		return result;	/* -ERESTARTSYS because signal hit process */
	case SG_SET_TIMEOUT:
		result = get_user(val, ip);
		if (result)
			return result;
		if (val < 0)
			return -EIO;
		if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
			val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
				    INT_MAX);
		sfp->timeout_user = val;
		sfp->timeout = mult_frac(val, HZ, USER_HZ);

		return 0;
	case SG_GET_TIMEOUT:	/* N.B. User receives timeout as return value */
				/* strange ..., for backward compatibility */
		return sfp->timeout_user;
	case SG_SET_FORCE_LOW_DMA:
		/*
		 * N.B. This ioctl never worked properly, but failed to
		 * return an error value. So returning '0' to keep compability
		 * with legacy applications.
		 */
		return 0;
	case SG_GET_LOW_DMA:
		return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
	case SG_GET_SCSI_ID:
		{
			sg_scsi_id_t v;

			if (atomic_read(&sdp->detaching))
				return -ENODEV;
			memset(&v, 0, sizeof(v));
			v.host_no = sdp->device->host->host_no;
			v.channel = sdp->device->channel;
			v.scsi_id = sdp->device->id;
			v.lun = sdp->device->lun;
			v.scsi_type = sdp->device->type;
			v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
			v.d_queue_depth = sdp->device->queue_depth;
			if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
				return -EFAULT;
			return 0;
		}
	case SG_SET_FORCE_PACK_ID:
		result = get_user(val, ip);
		if (result)
			return result;
		sfp->force_packid = val ? 1 : 0;
		return 0;
	case SG_GET_PACK_ID:
		read_lock_irqsave(&sfp->rq_list_lock, iflags);
		list_for_each_entry(srp, &sfp->rq_list, entry) {
			if ((1 == srp->done) && (!srp->sg_io_owned)) {
				read_unlock_irqrestore(&sfp->rq_list_lock,
						       iflags);
				return put_user(srp->header.pack_id, ip);
			}
		}
		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
		return put_user(-1, ip);
	case SG_GET_NUM_WAITING:
		read_lock_irqsave(&sfp->rq_list_lock, iflags);
		val = 0;
		list_for_each_entry(srp, &sfp->rq_list, entry) {
			if ((1 == srp->done) && (!srp->sg_io_owned))
				++val;
		}
		read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
		return put_user(val, ip);
	case SG_GET_SG_TABLESIZE:
		return put_user(sdp->sg_tablesize, ip);
	case SG_SET_RESERVED_SIZE:
		result = get_user(val, ip);
		if (result)
			return result;
                if (val < 0)
                        return -EINVAL;
		val = min_t(int, val,
			    max_sectors_bytes(sdp->device->request_queue));
		mutex_lock(&sfp->f_mutex);
		if (val != sfp->reserve.bufflen) {
			if (sfp->mmap_called ||
			    sfp->res_in_use) {
				mutex_unlock(&sfp->f_mutex);
				return -EBUSY;
			}

			sg_remove_scat(sfp, &sfp->reserve);
			sg_build_reserve(sfp, val);
		}
		mutex_unlock(&sfp->f_mutex);
		return 0;
	case SG_GET_RESERVED_SIZE:
		val = min_t(int, sfp->reserve.bufflen,
			    max_sectors_bytes(sdp->device->request_queue));
		return put_user(val, ip);
	case SG_SET_COMMAND_Q:
		result = get_user(val, ip);
		if (result)
			return result;
		sfp->cmd_q = val ? 1 : 0;
		return 0;
	case SG_GET_COMMAND_Q:
		return put_user((int) sfp->cmd_q, ip);
	case SG_SET_KEEP_ORPHAN:
		result = get_user(val, ip);
		if (result)
			return result;
		sfp->keep_orphan = val;
		return 0;
	case SG_GET_KEEP_ORPHAN:
		return put_user((int) sfp->keep_orphan, ip);
	case SG_NEXT_CMD_LEN:
		result = get_user(val, ip);
		if (result)
			return result;
		if (val > SG_MAX_CDB_SIZE)
			return -ENOMEM;
		sfp->next_cmd_len = (val > 0) ? val : 0;
		return 0;
	case SG_GET_VERSION_NUM:
		return put_user(sg_version_num, ip);
	case SG_GET_ACCESS_COUNT:
		/* faked - we don't have a real access count anymore */
		val = (sdp->device ? 1 : 0);
		return put_user(val, ip);
	case SG_GET_REQUEST_TABLE:
		{
			sg_req_info_t *rinfo;

			rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
					GFP_KERNEL);
			if (!rinfo)
				return -ENOMEM;
			read_lock_irqsave(&sfp->rq_list_lock, iflags);
			sg_fill_request_table(sfp, rinfo);
			read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
	#ifdef CONFIG_COMPAT
			if (in_compat_syscall())
				result = put_compat_request_table(p, rinfo);
			else
	#endif
				result = copy_to_user(p, rinfo,
						      SZ_SG_REQ_INFO * SG_MAX_QUEUE);
			result = result ? -EFAULT : 0;
			kfree(rinfo);
			return result;
		}
	case SG_EMULATED_HOST:
		if (atomic_read(&sdp->detaching))
			return -ENODEV;
		return put_user(sdp->device->host->hostt->emulated, ip);
	case SCSI_IOCTL_SEND_COMMAND:
		if (atomic_read(&sdp->detaching))
			return -ENODEV;
		return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
	case SG_SET_DEBUG:
		result = get_user(val, ip);
		if (result)
			return result;
		sdp->sgdebug = (char) val;
		return 0;
	case BLKSECTGET:
		return put_user(max_sectors_bytes(sdp->device->request_queue),
				ip);
	case BLKTRACESETUP:
		return blk_trace_setup(sdp->device->request_queue,
				       sdp->disk->disk_name,
				       MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
				       NULL, p);
	case BLKTRACESTART:
		return blk_trace_startstop(sdp->device->request_queue, 1);
	case BLKTRACESTOP:
		return blk_trace_startstop(sdp->device->request_queue, 0);
	case BLKTRACETEARDOWN:
		return blk_trace_remove(sdp->device->request_queue);
	case SCSI_IOCTL_GET_IDLUN:
	case SCSI_IOCTL_GET_BUS_NUMBER:
	case SCSI_IOCTL_PROBE_HOST:
	case SG_GET_TRANSFORM:
	case SG_SCSI_RESET:
		if (atomic_read(&sdp->detaching))
			return -ENODEV;
		break;
	default:
		if (read_only)
			return -EPERM;	/* don't know so take safe approach */
		break;
	}

	result = scsi_ioctl_block_when_processing_errors(sdp->device,
			cmd_in, filp->f_flags & O_NDELAY);
	if (result)
		return result;

	return -ENOIOCTLCMD;
}

Project: linux
File: sg.c

sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
{
	Sg_scatter_hold *schp = &srp->data;
	int k, num;

	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
			 "sg_read_oxfer: num_read_xfer=%d\n",
			 num_read_xfer));
	if ((!outp) || (num_read_xfer <= 0))
		return 0;

	num = 1 << (PAGE_SHIFT + schp->page_order);
	for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
		if (num > num_read_xfer) {
			if (copy_to_user(outp, page_address(schp->pages[k]),
					   num_read_xfer))
				return -EFAULT;
			break;
		} else {
			if (copy_to_user(outp, page_address(schp->pages[k]),
					   num))
				return -EFAULT;
			num_read_xfer -= num;
			if (num_read_xfer <= 0)
				break;
			outp += num;
		}
	}

	return 0;
}

Project: linux
File: sg.c

static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
{
	struct sg_header __user *old_hdr = buf;
	int reply_len;

	if (count >= SZ_SG_HEADER) {
		/* negative reply_len means v3 format, otherwise v1/v2 */
		if (get_user(reply_len, &old_hdr->reply_len))
			return -EFAULT;

		if (reply_len >= 0)
			return get_user(*pack_id, &old_hdr->pack_id);

		if (in_compat_syscall() &&
		    count >= sizeof(struct compat_sg_io_hdr)) {
			struct compat_sg_io_hdr __user *hp = buf;

			return get_user(*pack_id, &hp->pack_id);
		}

		if (count >= sizeof(struct sg_io_hdr)) {
			struct sg_io_hdr __user *hp = buf;

			return get_user(*pack_id, &hp->pack_id);
		}
	}

	/* no valid header was passed, so ignore the pack_id */
	*pack_id = -1;
	return 0;
}

Project: linux
File: sg.c

sg_start_req(Sg_request *srp, unsigned char *cmd)
{
	int res;
	struct request *rq;
	struct scsi_request *req;
	Sg_fd *sfp = srp->parentfp;
	sg_io_hdr_t *hp = &srp->header;
	int dxfer_len = (int) hp->dxfer_len;
	int dxfer_dir = hp->dxfer_direction;
	unsigned int iov_count = hp->iovec_count;
	Sg_scatter_hold *req_schp = &srp->data;
	Sg_scatter_hold *rsv_schp = &sfp->reserve;
	struct request_queue *q = sfp->parentdp->device->request_queue;
	struct rq_map_data *md, map_data;
	int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
	unsigned char *long_cmdp = NULL;

	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
				      "sg_start_req: dxfer_len=%d\n",
				      dxfer_len));

	if (hp->cmd_len > BLK_MAX_CDB) {
		long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
		if (!long_cmdp)
			return -ENOMEM;
	}

	/*
	 * NOTE
	 *
	 * With scsi-mq enabled, there are a fixed number of preallocated
	 * requests equal in number to shost->can_queue.  If all of the
	 * preallocated requests are already in use, then blk_get_request()
	 * will sleep until an active command completes, freeing up a request.
	 * Although waiting in an asynchronous interface is less than ideal, we
	 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
	 * not expect an EWOULDBLOCK from this condition.
	 */
	rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
	if (IS_ERR(rq)) {
		kfree(long_cmdp);
		return PTR_ERR(rq);
	}
	req = scsi_req(rq);

	if (hp->cmd_len > BLK_MAX_CDB)
		req->cmd = long_cmdp;
	memcpy(req->cmd, cmd, hp->cmd_len);
	req->cmd_len = hp->cmd_len;

	srp->rq = rq;
	rq->end_io_data = srp;
	req->retries = SG_DEFAULT_RETRIES;

	if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
		return 0;

	if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
	    dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
	    !sfp->parentdp->device->host->unchecked_isa_dma &&
	    blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
		md = NULL;
	else
		md = &map_data;

	if (md) {
		mutex_lock(&sfp->f_mutex);
		if (dxfer_len <= rsv_schp->bufflen &&
		    !sfp->res_in_use) {
			sfp->res_in_use = 1;
			sg_link_reserve(sfp, srp, dxfer_len);
		} else if (hp->flags & SG_FLAG_MMAP_IO) {
			res = -EBUSY; /* sfp->res_in_use == 1 */
			if (dxfer_len > rsv_schp->bufflen)
				res = -ENOMEM;
			mutex_unlock(&sfp->f_mutex);
			return res;
		} else {
			res = sg_build_indirect(req_schp, sfp, dxfer_len);
			if (res) {
				mutex_unlock(&sfp->f_mutex);
				return res;
			}
		}
		mutex_unlock(&sfp->f_mutex);

		md->pages = req_schp->pages;
		md->page_order = req_schp->page_order;
		md->nr_entries = req_schp->k_use_sg;
		md->offset = 0;
		md->null_mapped = hp->dxferp ? 0 : 1;
		if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
			md->from_user = 1;
		else
			md->from_user = 0;
	}

	if (iov_count) {
		struct iovec *iov = NULL;
		struct iov_iter i;

#ifdef CONFIG_COMPAT
		if (in_compat_syscall())
			res = compat_import_iovec(rw, hp->dxferp, iov_count,
						  0, &iov, &i);
		else
#endif
			res = import_iovec(rw, hp->dxferp, iov_count,
					   0, &iov, &i);
		if (res < 0)
			return res;

		iov_iter_truncate(&i, hp->dxfer_len);
		if (!iov_iter_count(&i)) {
			kfree(iov);
			return -EINVAL;
		}

		res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
		kfree(iov);
	} else
		res = blk_rq_map_user(q, rq, md, hp->dxferp,
				      hp->dxfer_len, GFP_ATOMIC);

	if (!res) {
		srp->bio = rq->bio;

		if (!md) {
			req_schp->dio_in_use = 1;
			hp->info |= SG_INFO_DIRECT_IO;
		}
	}
	return res;
}

Project: linux
File: sg.c

sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
{
	sg_io_hdr_t *hp = &srp->header;
	int err = 0, err2;
	int len;

	if (in_compat_syscall()) {
		if (count < sizeof(struct compat_sg_io_hdr)) {
			err = -EINVAL;
			goto err_out;
		}
	} else if (count < SZ_SG_IO_HDR) {
		err = -EINVAL;
		goto err_out;
	}
	hp->sb_len_wr = 0;
	if ((hp->mx_sb_len > 0) && hp->sbp) {
		if ((CHECK_CONDITION & hp->masked_status) ||
		    (DRIVER_SENSE & hp->driver_status)) {
			int sb_len = SCSI_SENSE_BUFFERSIZE;
			sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
			len = 8 + (int) srp->sense_b[7];	/* Additional sense length field */
			len = (len > sb_len) ? sb_len : len;
			if (copy_to_user(hp->sbp, srp->sense_b, len)) {
				err = -EFAULT;
				goto err_out;
			}
			hp->sb_len_wr = len;
		}
	}
	if (hp->masked_status || hp->host_status || hp->driver_status)
		hp->info |= SG_INFO_CHECK;
	err = put_sg_io_hdr(hp, buf);
err_out:
	err2 = sg_finish_rem_req(srp);
	sg_remove_request(sfp, srp);
	return err ? : err2 ? : count;
}

Project: linux
File: sg.c

sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
	void __user *p = (void __user *)arg;
	Sg_device *sdp;
	Sg_fd *sfp;
	int ret;

	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
		return -ENXIO;

	ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
	if (ret != -ENOIOCTLCMD)
		return ret;

	return scsi_ioctl(sdp->device, cmd_in, p);
}

Project: linux
File: sg.c

sg_common_write(Sg_fd * sfp, Sg_request * srp,
		unsigned char *cmnd, int timeout, int blocking)
{
	int k, at_head;
	Sg_device *sdp = sfp->parentdp;
	sg_io_hdr_t *hp = &srp->header;

	srp->data.cmd_opcode = cmnd[0];	/* hold opcode of command */
	hp->status = 0;
	hp->masked_status = 0;
	hp->msg_status = 0;
	hp->info = 0;
	hp->host_status = 0;
	hp->driver_status = 0;
	hp->resid = 0;
	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
			"sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
			(int) cmnd[0], (int) hp->cmd_len));

	if (hp->dxfer_len >= SZ_256M) {
		sg_remove_request(sfp, srp);
		return -EINVAL;
	}

	k = sg_start_req(srp, cmnd);
	if (k) {
		SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
			"sg_common_write: start_req err=%d\n", k));
		sg_finish_rem_req(srp);
		sg_remove_request(sfp, srp);
		return k;	/* probably out of space --> ENOMEM */
	}
	if (atomic_read(&sdp->detaching)) {
		if (srp->bio) {
			scsi_req_free_cmd(scsi_req(srp->rq));
			blk_put_request(srp->rq);
			srp->rq = NULL;
		}

		sg_finish_rem_req(srp);
		sg_remove_request(sfp, srp);
		return -ENODEV;
	}

	hp->duration = jiffies_to_msecs(jiffies);
	if (hp->interface_id != '\0' &&	/* v3 (or later) interface */
	    (SG_FLAG_Q_AT_TAIL & hp->flags))
		at_head = 0;
	else
		at_head = 1;

	srp->rq->timeout = timeout;
	kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
	blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
			      srp->rq, at_head, sg_rq_end_io);
	return 0;
}

Project: linux
File: sg.c

static int sg_check_file_access(struct file *filp, const char *caller)
{
	if (filp->f_cred != current_real_cred()) {
		pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
			caller, task_tgid_vnr(current), current->comm);
		return -EPERM;
	}
	if (uaccess_kernel()) {
		pr_err_once("%s: process %d (%s) called from kernel context, this is not allowed.\n",
			caller, task_tgid_vnr(current), current->comm);
		return -EACCES;
	}
	return 0;
}

Project: linux
File: sg.c

static int put_compat_request_table(struct compat_sg_req_info __user *o,
				    struct sg_req_info *rinfo)
{
	int i;
	for (i = 0; i < SG_MAX_QUEUE; i++) {
		if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
		    put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
		    put_user(rinfo[i].duration, &o[i].duration) ||
		    put_user(rinfo[i].unused, &o[i].unused))
			return -EFAULT;
	}
	return 0;
}

Project: linux
File: sg.c

sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
{
	int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
	int sg_tablesize = sfp->parentdp->sg_tablesize;
	int blk_size = buff_size, order;
	gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
	struct sg_device *sdp = sfp->parentdp;

	if (blk_size < 0)
		return -EFAULT;
	if (0 == blk_size)
		++blk_size;	/* don't know why */
	/* round request up to next highest SG_SECTOR_SZ byte boundary */
	blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
		"sg_build_indirect: buff_size=%d, blk_size=%d\n",
		buff_size, blk_size));

	/* N.B. ret_sz carried into this block ... */
	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
	if (mx_sc_elems < 0)
		return mx_sc_elems;	/* most likely -ENOMEM */

	num = scatter_elem_sz;
	if (unlikely(num != scatter_elem_sz_prev)) {
		if (num < PAGE_SIZE) {
			scatter_elem_sz = PAGE_SIZE;
			scatter_elem_sz_prev = PAGE_SIZE;
		} else
			scatter_elem_sz_prev = num;
	}

	if (sdp->device->host->unchecked_isa_dma)
		gfp_mask |= GFP_DMA;

	order = get_order(num);
retry:
	ret_sz = 1 << (PAGE_SHIFT + order);

	for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
	     k++, rem_sz -= ret_sz) {

		num = (rem_sz > scatter_elem_sz_prev) ?
			scatter_elem_sz_prev : rem_sz;

		schp->pages[k] = alloc_pages(gfp_mask, order);
		if (!schp->pages[k])
			goto out;

		if (num == scatter_elem_sz_prev) {
			if (unlikely(ret_sz > scatter_elem_sz_prev)) {
				scatter_elem_sz = ret_sz;
				scatter_elem_sz_prev = ret_sz;
			}
		}

		SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
				 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
				 k, num, ret_sz));
	}		/* end of for loop */

	schp->page_order = order;
	schp->k_use_sg = k;
	SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
			 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
			 k, rem_sz));

	schp->bufflen = blk_size;
	if (rem_sz > 0)	/* must have failed */
		return -ENOMEM;
	return 0;
out:
	for (i = 0; i < k; i++)
		__free_pages(schp->pages[i], order);

	if (--order >= 0)
		goto retry;

	return -ENOMEM;
}