4.4-stable review patch. If anyone has any objections, please let me know.
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From: Johannes Thumshirn jthumshirn@suse.de
commit 48ae8484e9fc324b4968d33c585e54bc98e44d61 upstream.
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 Reviewed-by: Hannes Reinecke hare@suse.de Acked-by: Doug Gilbert dgilbert@interlog.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Cc: Tony Battersby tonyb@cybernetics.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/scsi/sg.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- 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 */