[linux-yocto] [linux-yocto-4.12][PATCH 1/1] ide:ide-cd: fix kernel panic resulting from missing scsi_req_init

[Bruce Ashfield]

On 2017-10-31 10:01 PM, Hongxu Jia wrote:
> Since we split the scsi_request out of struct request, while the
> standard prep_rq_fn builds 10 byte cmds, it missed to invoke
> scsi_req_init() to initialize certain fields of a scsi_request
> structure (.__cmd[], .cmd, .cmd_len and .sense_len but no other
> members of struct scsi_request).
> 
> An example panic on virtual machines (qemu/virtualbox) to boot
> from IDE cdrom:
> ...
> [    8.754381] Call Trace:
> [    8.755419]  blk_peek_request+0x182/0x2e0
> [    8.755863]  blk_fetch_request+0x1c/0x40
> [    8.756148]  ? ktime_get+0x40/0xa0
> [    8.756385]  do_ide_request+0x37d/0x660
> [    8.756704]  ? cfq_group_service_tree_add+0x98/0xc0
> [    8.757011]  ? cfq_service_tree_add+0x1e5/0x2c0
> [    8.757313]  ? ktime_get+0x40/0xa0
> [    8.757544]  __blk_run_queue+0x3d/0x60
> [    8.757837]  queue_unplugged+0x2f/0xc0
> [    8.758088]  blk_flush_plug_list+0x1f4/0x240
> [    8.758362]  blk_finish_plug+0x2c/0x40
> ...
> [    8.770906] RIP: ide_cdrom_prep_fn+0x63/0x180 RSP: ffff92aec018bae8
> [    8.772329] ---[ end trace 6408481e551a85c9 ]---
> ...
> 
> Fixes: 82ed4db499b8 ("block: split scsi_request out of struct request")
> 
> Upstream-Status: Submitted [linux-block at vger.kernel.org]

I'll drop this during merge, but do you have a link to the mailing
list archive for this ?

We should capture that, and I'd like to follow along to see what
upstream says.

Bruce

> 
> Signed-off-by: Hongxu Jia <hongxu.jia at windriver.com>
> ---
>   drivers/ide/ide-cd.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
> index 07e5ff3..f13ad9d 100644
> --- a/drivers/ide/ide-cd.c
> +++ b/drivers/ide/ide-cd.c
> @@ -1329,6 +1329,7 @@ static int ide_cdrom_prep_fs(struct request_queue *q, struct request *rq)
>   	unsigned long blocks = blk_rq_sectors(rq) / (hard_sect >> 9);
>   	struct scsi_request *req = scsi_req(rq);
>   
> +	scsi_req_init(rq);
>   	memset(req->cmd, 0, BLK_MAX_CDB);
>   
>   	if (rq_data_dir(rq) == READ)
>