| Message ID | 20170510075340.12125-1-jthumshirn@suse.de (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
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@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> > --- > 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@suse.com> Cheers, Hannes
On 2017-05-10 03:53 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@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> > --- > 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 */ > Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Johannes, > 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. Applied to 4.12/scsi-fixes, thanks!
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 */
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> --- Changes to v1: * Directly return found element within the loop (Hannes) drivers/scsi/sg.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)