On 05/10/2017 09:53 AM, Johannes Thumshirn wrote:
> If the list search in sg_get_rq_mark() fails to find a valid request, we
> return a bogus element. This then can later lead to a GPF in sg_remove_scat().
>
> So don't return bogus Sg_requests in sg_get_rq_mark() but NULL in case the
> list search doesn't find a valid request.
>
> Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
> Reported-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> Cc: Hannes Reinecke <hare@xxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Doug Gilbert <dgilbert@xxxxxxxxxxxx>
> ---
> Changes to v1:
> * Directly return found element within the loop (Hannes)
>
> drivers/scsi/sg.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
> index 0a38ba01b7b4..82c33a6edbea 100644
> --- a/drivers/scsi/sg.c
> +++ b/drivers/scsi/sg.c
> @@ -2074,11 +2074,12 @@ sg_get_rq_mark(Sg_fd * sfp, int pack_id)
> if ((1 == resp->done) && (!resp->sg_io_owned) &&
> ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
> resp->done = 2; /* guard against other readers */
> - break;
> + write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
> + return resp;
> }
> }
> write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
> - return resp;
> + return NULL;
> }
>
> /* always adds to end of list */
>
Better.
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
