| Message ID | 20170510074139.11179-1-jthumshirn@suse.de (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On 05/10/2017 09:41 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@suse.de> > Reported-by: Andrey Konovalov <andreyknvl@google.com> > Cc: Hannes Reinecke <hare@suse.de> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Doug Gilbert <dgilbert@interlog.com> > --- > drivers/scsi/sg.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c > index 0a38ba01b7b4..abfde23fa186 100644 > --- a/drivers/scsi/sg.c > +++ b/drivers/scsi/sg.c > @@ -2078,7 +2078,7 @@ sg_get_rq_mark(Sg_fd * sfp, int pack_id) > } > } > write_unlock_irqrestore(&sfp->rq_list_lock, iflags); > - return resp; > + return (resp->done == 2) ? resp : NULL; > } > > /* always adds to end of list */ > Not quite. Please return 'resp' directly from within the loop. With this fix we run into the risk that by chance the uninitialized 'resp' pointer contains a '2' at the 'done' location, triggering this issue again. Cheers, Hannes
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 0a38ba01b7b4..abfde23fa186 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -2078,7 +2078,7 @@ sg_get_rq_mark(Sg_fd * sfp, int pack_id) } } write_unlock_irqrestore(&sfp->rq_list_lock, iflags); - return resp; + return (resp->done == 2) ? resp : NULL; } /* always adds to end of list */
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@suse.de> Reported-by: Andrey Konovalov <andreyknvl@google.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Doug Gilbert <dgilbert@interlog.com> --- drivers/scsi/sg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)