[PATCH 2.6.14.3] 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. Signed-off-by: Stefan Richter --- 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. drivers/scsi/scsi_lib.c | 13 +------------ drivers/scsi/sr.c | 20 +++----------------- drivers/scsi/st.c | 19 +------------------ 3 files changed, 5 insertions(+), 47 deletions(-) --- linux-2.6.14.3/drivers/scsi.orig/scsi_lib.c 2005-11-24 23:10:21.000000000 +0100 +++ linux-2.6.14.3/drivers/scsi/scsi_lib.c 2005-12-14 22:23:13.000000000 +0100 @@ -1284,18 +1304,7 @@ 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-2.6.14.3/drivers/scsi.orig/sr.c 2005-11-24 23:10:21.000000000 +0100 +++ linux-2.6.14.3/drivers/scsi/sr.c 2005-12-14 22:23:13.000000000 +0100 @@ -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-2.6.14.3/drivers/scsi.orig/st.c 2005-11-24 23:10:21.000000000 +0100 +++ linux-2.6.14.3/drivers/scsi/st.c 2005-12-14 22:23:13.000000000 +0100 @@ -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; }