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 --- block/scsi_ioctl.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'block/scsi_ioctl.c') diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index 51bf5155ee75..29d056782833 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -448,6 +448,10 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode, } rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_WAIT); + if (!rq) { + err = -ENODEV; + goto error_free_buffer; + } cmdlen = COMMAND_SIZE(opcode); @@ -520,8 +524,9 @@ out: } error: - kfree(buffer); blk_put_request(rq); +error_free_buffer: + kfree(buffer); return err; } EXPORT_SYMBOL_GPL(sg_scsi_ioctl); @@ -534,6 +539,8 @@ static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk, int err; rq = blk_get_request(q, WRITE, __GFP_WAIT); + if (!rq) + return -ENODEV; blk_rq_set_block_pc(rq); rq->timeout = BLK_DEFAULT_SG_TIMEOUT; rq->cmd[0] = cmd; -- cgit