[patch 18/19] SCSI: fix transfer direction in scsi_lib and st

Greg Kroah-Hartman
2005-12-23T22:49:20Z

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-stable review patch. If anyone has any objections, please let us know.

------------------
From: Stefan Richter <stefanr@s5r6.in-berlin.de>

SCSI: fix transfer direction in scsi_lib and st

scsi_prep_fn and st_init_command could issue WRITE requests with zero
buffer length. This may lead to kernel panic or oops with some SCSI
low-level drivers.

Derived from -rc patches from Jens Axboe and James Bottomley.

Patch is reassembled for -stable from patches:
[SCSI] fix panic when ejecting ieee1394 ipod
[SCSI] Consolidate REQ_BLOCK_PC handling path (fix ipod panic)

Depends on patch "SCSI: fix transfer direction in sd (kernel panic when
ejecting iPod)". Also modifies the already correct sr_init_command to
fully match the corresponding -rc patch.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/scsi/scsi_lib.c | 13 +------------
drivers/scsi/sr.c | 20 +++-----------------
drivers/scsi/st.c | 19 +------------------
3 files changed, 5 insertions(+), 47 deletions(-)

--- linux-2.6.14.4.orig/drivers/scsi/scsi_lib.c
+++ linux-2.6.14.4/drivers/scsi/scsi_lib.c
@@ -1284,18 +1284,7 @@ static int scsi_prep_fn(struct request_q
goto kill;
}
} else {
- memcpy(cmd->cmnd, req->cmd, sizeof(cmd->cmnd));
- cmd->cmd_len = req->cmd_len;
- if (rq_data_dir(req) == WRITE)
- cmd->sc_data_direction = DMA_TO_DEVICE;
- else if (req->data_len)
- cmd->sc_data_direction = DMA_FROM_DEVICE;
- else
- cmd->sc_data_direction = DMA_NONE;
-
- cmd->transfersize = req->data_len;
- cmd->allowed = 3;
- cmd->timeout_per_command = req->timeout;
+ scsi_setup_blk_pc_cmnd(cmd, 3);
cmd->done = scsi_generic_done;
}
}
--- linux-2.6.14.4.orig/drivers/scsi/sr.c
+++ linux-2.6.14.4/drivers/scsi/sr.c
@@ -320,25 +320,11 @@ static int sr_init_command(struct scsi_c
* these are already setup, just copy cdb basically
*/
if (SCpnt->request->flags & REQ_BLOCK_PC) {
- struct request *rq = SCpnt->request;
+ scsi_setup_blk_pc_cmnd(SCpnt, MAX_RETRIES);

- if (sizeof(rq->cmd) > sizeof(SCpnt->cmnd))
- return 0;
-
- memcpy(SCpnt->cmnd, rq->cmd, sizeof(SCpnt->cmnd));
- SCpnt->cmd_len = rq->cmd_len;
- if (!rq->data_len)
- SCpnt->sc_data_direction = DMA_NONE;
- else if (rq_data_dir(rq) == WRITE)
- SCpnt->sc_data_direction = DMA_TO_DEVICE;
- else
- SCpnt->sc_data_direction = DMA_FROM_DEVICE;
-
- this_count = rq->data_len;
- if (rq->timeout)
- timeout = rq->timeout;
+ if (SCpnt->timeout_per_command)
+ timeout = SCpnt->timeout_per_command;

- SCpnt->transfersize = rq->data_len;
goto queue;
}

--- linux-2.6.14.4.orig/drivers/scsi/st.c
+++ linux-2.6.14.4/drivers/scsi/st.c
@@ -4196,27 +4196,10 @@ static void st_intr(struct scsi_cmnd *SC
*/
static int st_init_command(struct scsi_cmnd *SCpnt)
{
- struct request *rq;
-
if (!(SCpnt->request->flags & REQ_BLOCK_PC))
return 0;

- rq = SCpnt->request;
- if (sizeof(rq->cmd) > sizeof(SCpnt->cmnd))
- return 0;
-
- memcpy(SCpnt->cmnd, rq->cmd, sizeof(SCpnt->cmnd));
- SCpnt->cmd_len = rq->cmd_len;
-
- if (rq_data_dir(rq) == WRITE)
- SCpnt->sc_data_direction = DMA_TO_DEVICE;
- else if (rq->data_len)
- SCpnt->sc_data_direction = DMA_FROM_DEVICE;
- else
- SCpnt->sc_data_direction = DMA_NONE;
-
- SCpnt->timeout_per_command = rq->timeout;
- SCpnt->transfersize = rq->data_len;
+ scsi_setup_blk_pc_cmnd(SCpnt, 0);
SCpnt->done = st_intr;
return 1;
}

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