From eb571eeade2598635f813b3284d02c13a380301e Mon Sep 17 00:00:00 2001 From: Joe Lawrence Date: Wed, 2 Jul 2014 15:35:16 -0400 Subject: block,scsi: verify return pointer from blk_get_request The blk-core dead queue checks introduce an error scenario to blk_get_request that returns NULL if the request queue has been shutdown. This affects the behavior for __GFP_WAIT callers, who should verify the return value before dereferencing. Signed-off-by: Joe Lawrence Acked-by: Jiri Kosina [for pktdvd] Reviewed-by: Jeff Moyer Signed-off-by: Jens Axboe --- drivers/block/paride/pd.c | 2 ++ drivers/block/pktcdvd.c | 2 ++ drivers/scsi/scsi_error.c | 2 ++ 3 files changed, 6 insertions(+) (limited to 'drivers') diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c index fea7e76a00de..ca831f741d89 100644 --- a/drivers/block/paride/pd.c +++ b/drivers/block/paride/pd.c @@ -722,6 +722,8 @@ static int pd_special_command(struct pd_unit *disk, int err = 0; rq = blk_get_request(disk->gd->queue, READ, __GFP_WAIT); + if (!rq) + return -ENODEV; rq->cmd_type = REQ_TYPE_SPECIAL; rq->special = func; diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c index 758ac442c5b5..7fa8c80e8982 100644 --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -704,6 +704,8 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command * rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ? WRITE : READ, __GFP_WAIT); + if (!rq) + return -ENODEV; blk_rq_set_block_pc(rq); if (cgc->buflen) { diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 5db8454474ee..4c433bf47a06 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -1960,6 +1960,8 @@ static void scsi_eh_lock_door(struct scsi_device *sdev) * request becomes available */ req = blk_get_request(sdev->request_queue, READ, GFP_KERNEL); + if (!req) + return; blk_rq_set_block_pc(req); -- cgit