mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![Christoph Hellwig](/assets/img/avatar_default.png)
Set ret to 0 after the initial permission checks to avoid leaking -EPERM
for commands without data transfer.
Link: https://lore.kernel.org/r/20210731074027.1185545-3-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>
415 lines
10 KiB
C
415 lines
10 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* BSG helper library
|
|
*
|
|
* Copyright (C) 2008 James Smart, Emulex Corporation
|
|
* Copyright (C) 2011 Red Hat, Inc. All rights reserved.
|
|
* Copyright (C) 2011 Mike Christie
|
|
*/
|
|
#include <linux/bsg.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/blk-mq.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/scatterlist.h>
|
|
#include <linux/bsg-lib.h>
|
|
#include <linux/export.h>
|
|
#include <scsi/scsi_cmnd.h>
|
|
#include <scsi/sg.h>
|
|
|
|
#define uptr64(val) ((void __user *)(uintptr_t)(val))
|
|
|
|
struct bsg_set {
|
|
struct blk_mq_tag_set tag_set;
|
|
struct bsg_device *bd;
|
|
bsg_job_fn *job_fn;
|
|
bsg_timeout_fn *timeout_fn;
|
|
};
|
|
|
|
static int bsg_transport_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
|
|
fmode_t mode, unsigned int timeout)
|
|
{
|
|
struct bsg_job *job;
|
|
struct request *rq;
|
|
struct bio *bio;
|
|
int ret;
|
|
|
|
if (hdr->protocol != BSG_PROTOCOL_SCSI ||
|
|
hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_TRANSPORT)
|
|
return -EINVAL;
|
|
if (!capable(CAP_SYS_RAWIO))
|
|
return -EPERM;
|
|
|
|
rq = blk_get_request(q, hdr->dout_xfer_len ?
|
|
REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
|
|
if (IS_ERR(rq))
|
|
return PTR_ERR(rq);
|
|
rq->timeout = timeout;
|
|
|
|
job = blk_mq_rq_to_pdu(rq);
|
|
job->request_len = hdr->request_len;
|
|
job->request = memdup_user(uptr64(hdr->request), hdr->request_len);
|
|
if (IS_ERR(job->request)) {
|
|
ret = PTR_ERR(job->request);
|
|
goto out_put_request;
|
|
}
|
|
|
|
if (hdr->dout_xfer_len && hdr->din_xfer_len) {
|
|
job->bidi_rq = blk_get_request(rq->q, REQ_OP_DRV_IN, 0);
|
|
if (IS_ERR(job->bidi_rq)) {
|
|
ret = PTR_ERR(job->bidi_rq);
|
|
goto out_free_job_request;
|
|
}
|
|
|
|
ret = blk_rq_map_user(rq->q, job->bidi_rq, NULL,
|
|
uptr64(hdr->din_xferp), hdr->din_xfer_len,
|
|
GFP_KERNEL);
|
|
if (ret)
|
|
goto out_free_bidi_rq;
|
|
|
|
job->bidi_bio = job->bidi_rq->bio;
|
|
} else {
|
|
job->bidi_rq = NULL;
|
|
job->bidi_bio = NULL;
|
|
}
|
|
|
|
ret = 0;
|
|
if (hdr->dout_xfer_len) {
|
|
ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp),
|
|
hdr->dout_xfer_len, GFP_KERNEL);
|
|
} else if (hdr->din_xfer_len) {
|
|
ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp),
|
|
hdr->din_xfer_len, GFP_KERNEL);
|
|
}
|
|
|
|
if (ret)
|
|
goto out_unmap_bidi_rq;
|
|
|
|
bio = rq->bio;
|
|
blk_execute_rq(NULL, rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL));
|
|
|
|
/*
|
|
* The assignments below don't make much sense, but are kept for
|
|
* bug by bug backwards compatibility:
|
|
*/
|
|
hdr->device_status = job->result & 0xff;
|
|
hdr->transport_status = host_byte(job->result);
|
|
hdr->driver_status = 0;
|
|
hdr->info = 0;
|
|
if (hdr->device_status || hdr->transport_status || hdr->driver_status)
|
|
hdr->info |= SG_INFO_CHECK;
|
|
hdr->response_len = 0;
|
|
|
|
if (job->result < 0) {
|
|
/* we're only returning the result field in the reply */
|
|
job->reply_len = sizeof(u32);
|
|
ret = job->result;
|
|
}
|
|
|
|
if (job->reply_len && hdr->response) {
|
|
int len = min(hdr->max_response_len, job->reply_len);
|
|
|
|
if (copy_to_user(uptr64(hdr->response), job->reply, len))
|
|
ret = -EFAULT;
|
|
else
|
|
hdr->response_len = len;
|
|
}
|
|
|
|
/* we assume all request payload was transferred, residual == 0 */
|
|
hdr->dout_resid = 0;
|
|
|
|
if (job->bidi_rq) {
|
|
unsigned int rsp_len = job->reply_payload.payload_len;
|
|
|
|
if (WARN_ON(job->reply_payload_rcv_len > rsp_len))
|
|
hdr->din_resid = 0;
|
|
else
|
|
hdr->din_resid = rsp_len - job->reply_payload_rcv_len;
|
|
} else {
|
|
hdr->din_resid = 0;
|
|
}
|
|
|
|
blk_rq_unmap_user(bio);
|
|
out_unmap_bidi_rq:
|
|
if (job->bidi_rq)
|
|
blk_rq_unmap_user(job->bidi_bio);
|
|
out_free_bidi_rq:
|
|
if (job->bidi_rq)
|
|
blk_put_request(job->bidi_rq);
|
|
out_free_job_request:
|
|
kfree(job->request);
|
|
out_put_request:
|
|
blk_put_request(rq);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* bsg_teardown_job - routine to teardown a bsg job
|
|
* @kref: kref inside bsg_job that is to be torn down
|
|
*/
|
|
static void bsg_teardown_job(struct kref *kref)
|
|
{
|
|
struct bsg_job *job = container_of(kref, struct bsg_job, kref);
|
|
struct request *rq = blk_mq_rq_from_pdu(job);
|
|
|
|
put_device(job->dev); /* release reference for the request */
|
|
|
|
kfree(job->request_payload.sg_list);
|
|
kfree(job->reply_payload.sg_list);
|
|
|
|
blk_mq_end_request(rq, BLK_STS_OK);
|
|
}
|
|
|
|
void bsg_job_put(struct bsg_job *job)
|
|
{
|
|
kref_put(&job->kref, bsg_teardown_job);
|
|
}
|
|
EXPORT_SYMBOL_GPL(bsg_job_put);
|
|
|
|
int bsg_job_get(struct bsg_job *job)
|
|
{
|
|
return kref_get_unless_zero(&job->kref);
|
|
}
|
|
EXPORT_SYMBOL_GPL(bsg_job_get);
|
|
|
|
/**
|
|
* bsg_job_done - completion routine for bsg requests
|
|
* @job: bsg_job that is complete
|
|
* @result: job reply result
|
|
* @reply_payload_rcv_len: length of payload recvd
|
|
*
|
|
* The LLD should call this when the bsg job has completed.
|
|
*/
|
|
void bsg_job_done(struct bsg_job *job, int result,
|
|
unsigned int reply_payload_rcv_len)
|
|
{
|
|
struct request *rq = blk_mq_rq_from_pdu(job);
|
|
|
|
job->result = result;
|
|
job->reply_payload_rcv_len = reply_payload_rcv_len;
|
|
if (likely(!blk_should_fake_timeout(rq->q)))
|
|
blk_mq_complete_request(rq);
|
|
}
|
|
EXPORT_SYMBOL_GPL(bsg_job_done);
|
|
|
|
/**
|
|
* bsg_complete - softirq done routine for destroying the bsg requests
|
|
* @rq: BSG request that holds the job to be destroyed
|
|
*/
|
|
static void bsg_complete(struct request *rq)
|
|
{
|
|
struct bsg_job *job = blk_mq_rq_to_pdu(rq);
|
|
|
|
bsg_job_put(job);
|
|
}
|
|
|
|
static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
|
|
{
|
|
size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
|
|
|
|
BUG_ON(!req->nr_phys_segments);
|
|
|
|
buf->sg_list = kmalloc(sz, GFP_KERNEL);
|
|
if (!buf->sg_list)
|
|
return -ENOMEM;
|
|
sg_init_table(buf->sg_list, req->nr_phys_segments);
|
|
buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
|
|
buf->payload_len = blk_rq_bytes(req);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* bsg_prepare_job - create the bsg_job structure for the bsg request
|
|
* @dev: device that is being sent the bsg request
|
|
* @req: BSG request that needs a job structure
|
|
*/
|
|
static bool bsg_prepare_job(struct device *dev, struct request *req)
|
|
{
|
|
struct bsg_job *job = blk_mq_rq_to_pdu(req);
|
|
int ret;
|
|
|
|
job->timeout = req->timeout;
|
|
|
|
if (req->bio) {
|
|
ret = bsg_map_buffer(&job->request_payload, req);
|
|
if (ret)
|
|
goto failjob_rls_job;
|
|
}
|
|
if (job->bidi_rq) {
|
|
ret = bsg_map_buffer(&job->reply_payload, job->bidi_rq);
|
|
if (ret)
|
|
goto failjob_rls_rqst_payload;
|
|
}
|
|
job->dev = dev;
|
|
/* take a reference for the request */
|
|
get_device(job->dev);
|
|
kref_init(&job->kref);
|
|
return true;
|
|
|
|
failjob_rls_rqst_payload:
|
|
kfree(job->request_payload.sg_list);
|
|
failjob_rls_job:
|
|
job->result = -ENOMEM;
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* bsg_queue_rq - generic handler for bsg requests
|
|
* @hctx: hardware queue
|
|
* @bd: queue data
|
|
*
|
|
* On error the create_bsg_job function should return a -Exyz error value
|
|
* that will be set to ->result.
|
|
*
|
|
* Drivers/subsys should pass this to the queue init function.
|
|
*/
|
|
static blk_status_t bsg_queue_rq(struct blk_mq_hw_ctx *hctx,
|
|
const struct blk_mq_queue_data *bd)
|
|
{
|
|
struct request_queue *q = hctx->queue;
|
|
struct device *dev = q->queuedata;
|
|
struct request *req = bd->rq;
|
|
struct bsg_set *bset =
|
|
container_of(q->tag_set, struct bsg_set, tag_set);
|
|
blk_status_t sts = BLK_STS_IOERR;
|
|
int ret;
|
|
|
|
blk_mq_start_request(req);
|
|
|
|
if (!get_device(dev))
|
|
return BLK_STS_IOERR;
|
|
|
|
if (!bsg_prepare_job(dev, req))
|
|
goto out;
|
|
|
|
ret = bset->job_fn(blk_mq_rq_to_pdu(req));
|
|
if (!ret)
|
|
sts = BLK_STS_OK;
|
|
|
|
out:
|
|
put_device(dev);
|
|
return sts;
|
|
}
|
|
|
|
/* called right after the request is allocated for the request_queue */
|
|
static int bsg_init_rq(struct blk_mq_tag_set *set, struct request *req,
|
|
unsigned int hctx_idx, unsigned int numa_node)
|
|
{
|
|
struct bsg_job *job = blk_mq_rq_to_pdu(req);
|
|
|
|
job->reply = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
|
|
if (!job->reply)
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
|
|
/* called right before the request is given to the request_queue user */
|
|
static void bsg_initialize_rq(struct request *req)
|
|
{
|
|
struct bsg_job *job = blk_mq_rq_to_pdu(req);
|
|
void *reply = job->reply;
|
|
|
|
memset(job, 0, sizeof(*job));
|
|
job->reply = reply;
|
|
job->reply_len = SCSI_SENSE_BUFFERSIZE;
|
|
job->dd_data = job + 1;
|
|
}
|
|
|
|
static void bsg_exit_rq(struct blk_mq_tag_set *set, struct request *req,
|
|
unsigned int hctx_idx)
|
|
{
|
|
struct bsg_job *job = blk_mq_rq_to_pdu(req);
|
|
|
|
kfree(job->reply);
|
|
}
|
|
|
|
void bsg_remove_queue(struct request_queue *q)
|
|
{
|
|
if (q) {
|
|
struct bsg_set *bset =
|
|
container_of(q->tag_set, struct bsg_set, tag_set);
|
|
|
|
bsg_unregister_queue(bset->bd);
|
|
blk_cleanup_queue(q);
|
|
blk_mq_free_tag_set(&bset->tag_set);
|
|
kfree(bset);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(bsg_remove_queue);
|
|
|
|
static enum blk_eh_timer_return bsg_timeout(struct request *rq, bool reserved)
|
|
{
|
|
struct bsg_set *bset =
|
|
container_of(rq->q->tag_set, struct bsg_set, tag_set);
|
|
|
|
if (!bset->timeout_fn)
|
|
return BLK_EH_DONE;
|
|
return bset->timeout_fn(rq);
|
|
}
|
|
|
|
static const struct blk_mq_ops bsg_mq_ops = {
|
|
.queue_rq = bsg_queue_rq,
|
|
.init_request = bsg_init_rq,
|
|
.exit_request = bsg_exit_rq,
|
|
.initialize_rq_fn = bsg_initialize_rq,
|
|
.complete = bsg_complete,
|
|
.timeout = bsg_timeout,
|
|
};
|
|
|
|
/**
|
|
* bsg_setup_queue - Create and add the bsg hooks so we can receive requests
|
|
* @dev: device to attach bsg device to
|
|
* @name: device to give bsg device
|
|
* @job_fn: bsg job handler
|
|
* @timeout: timeout handler function pointer
|
|
* @dd_job_size: size of LLD data needed for each job
|
|
*/
|
|
struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
|
|
bsg_job_fn *job_fn, bsg_timeout_fn *timeout, int dd_job_size)
|
|
{
|
|
struct bsg_set *bset;
|
|
struct blk_mq_tag_set *set;
|
|
struct request_queue *q;
|
|
int ret = -ENOMEM;
|
|
|
|
bset = kzalloc(sizeof(*bset), GFP_KERNEL);
|
|
if (!bset)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
bset->job_fn = job_fn;
|
|
bset->timeout_fn = timeout;
|
|
|
|
set = &bset->tag_set;
|
|
set->ops = &bsg_mq_ops;
|
|
set->nr_hw_queues = 1;
|
|
set->queue_depth = 128;
|
|
set->numa_node = NUMA_NO_NODE;
|
|
set->cmd_size = sizeof(struct bsg_job) + dd_job_size;
|
|
set->flags = BLK_MQ_F_NO_SCHED | BLK_MQ_F_BLOCKING;
|
|
if (blk_mq_alloc_tag_set(set))
|
|
goto out_tag_set;
|
|
|
|
q = blk_mq_init_queue(set);
|
|
if (IS_ERR(q)) {
|
|
ret = PTR_ERR(q);
|
|
goto out_queue;
|
|
}
|
|
|
|
q->queuedata = dev;
|
|
blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
|
|
|
|
bset->bd = bsg_register_queue(q, dev, name, bsg_transport_sg_io_fn);
|
|
if (IS_ERR(bset->bd)) {
|
|
ret = PTR_ERR(bset->bd);
|
|
goto out_cleanup_queue;
|
|
}
|
|
|
|
return q;
|
|
out_cleanup_queue:
|
|
blk_cleanup_queue(q);
|
|
out_queue:
|
|
blk_mq_free_tag_set(set);
|
|
out_tag_set:
|
|
kfree(bset);
|
|
return ERR_PTR(ret);
|
|
}
|
|
EXPORT_SYMBOL_GPL(bsg_setup_queue);
|