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5c0f61377b
Set ret to 0 after the initial permission checks to avoid leaking -EPERM
for commands without data transfer.
Link: https://lore.kernel.org/r/20210731074027.1185545-2-hch@lst.de
Fixes: 75ca56409e ("scsi: bsg: Move the whole request execution into the SCSI/transport handlers")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
107 lines
2.6 KiB
C
107 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/bsg.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_ioctl.h>
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#include <scsi/scsi_cmnd.h>
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#include <scsi/scsi_device.h>
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#include <scsi/sg.h>
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#include "scsi_priv.h"
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#define uptr64(val) ((void __user *)(uintptr_t)(val))
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static int scsi_bsg_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
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fmode_t mode, unsigned int timeout)
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{
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struct scsi_request *sreq;
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struct request *rq;
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struct bio *bio;
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int ret;
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if (hdr->protocol != BSG_PROTOCOL_SCSI ||
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hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_CMD)
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return -EINVAL;
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if (hdr->dout_xfer_len && hdr->din_xfer_len) {
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pr_warn_once("BIDI support in bsg has been removed.\n");
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return -EOPNOTSUPP;
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}
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rq = blk_get_request(q, hdr->dout_xfer_len ?
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REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
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if (IS_ERR(rq))
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return PTR_ERR(rq);
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rq->timeout = timeout;
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ret = -ENOMEM;
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sreq = scsi_req(rq);
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sreq->cmd_len = hdr->request_len;
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if (sreq->cmd_len > BLK_MAX_CDB) {
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sreq->cmd = kzalloc(sreq->cmd_len, GFP_KERNEL);
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if (!sreq->cmd)
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goto out_put_request;
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}
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ret = -EFAULT;
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if (copy_from_user(sreq->cmd, uptr64(hdr->request), sreq->cmd_len))
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goto out_free_cmd;
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ret = -EPERM;
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if (!scsi_cmd_allowed(sreq->cmd, mode))
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goto out_free_cmd;
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ret = 0;
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if (hdr->dout_xfer_len) {
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ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp),
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hdr->dout_xfer_len, GFP_KERNEL);
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} else if (hdr->din_xfer_len) {
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ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp),
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hdr->din_xfer_len, GFP_KERNEL);
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}
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if (ret)
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goto out_free_cmd;
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bio = rq->bio;
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blk_execute_rq(NULL, rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL));
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/*
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* fill in all the output members
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*/
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hdr->device_status = sreq->result & 0xff;
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hdr->transport_status = host_byte(sreq->result);
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hdr->driver_status = 0;
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if (scsi_status_is_check_condition(sreq->result))
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hdr->driver_status = DRIVER_SENSE;
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hdr->info = 0;
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if (hdr->device_status || hdr->transport_status || hdr->driver_status)
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hdr->info |= SG_INFO_CHECK;
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hdr->response_len = 0;
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if (sreq->sense_len && hdr->response) {
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int len = min_t(unsigned int, hdr->max_response_len,
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sreq->sense_len);
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if (copy_to_user(uptr64(hdr->response), sreq->sense, len))
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ret = -EFAULT;
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else
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hdr->response_len = len;
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}
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if (rq_data_dir(rq) == READ)
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hdr->din_resid = sreq->resid_len;
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else
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hdr->dout_resid = sreq->resid_len;
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blk_rq_unmap_user(bio);
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out_free_cmd:
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scsi_req_free_cmd(scsi_req(rq));
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out_put_request:
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blk_put_request(rq);
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return ret;
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}
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struct bsg_device *scsi_bsg_register_queue(struct scsi_device *sdev)
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{
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return bsg_register_queue(sdev->request_queue, &sdev->sdev_gendev,
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dev_name(&sdev->sdev_gendev), scsi_bsg_sg_io_fn);
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}
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