[src/trunk]: src/sys/dev Bounds check against media size for non-persistent s...

[hannken <hannken%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/5c0bdc1bbcce
branches:  trunk
changeset: 358322:5c0bdc1bbcce
user:      hannken <hannken%NetBSD.org@localhost>
date:      Thu Dec 21 15:51:07 2017 +0000

description:
Bounds check against media size for non-persistent snapshots.

diffstat:

 sys/dev/fss.c |  22 ++++++++++++++--------
 1 files changed, 14 insertions(+), 8 deletions(-)

diffs (51 lines):

diff -r f52aa79e89cd -r 5c0bdc1bbcce sys/dev/fss.c
--- a/sys/dev/fss.c     Thu Dec 21 15:50:33 2017 +0000
+++ b/sys/dev/fss.c     Thu Dec 21 15:51:07 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: fss.c,v 1.101 2017/12/21 15:50:33 hannken Exp $        */
+/*     $NetBSD: fss.c,v 1.102 2017/12/21 15:51:07 hannken Exp $        */
 
 /*-
  * Copyright (c) 2003 The NetBSD Foundation, Inc.
@@ -36,7 +36,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fss.c,v 1.101 2017/12/21 15:50:33 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fss.c,v 1.102 2017/12/21 15:51:07 hannken Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -280,20 +280,26 @@
        mutex_enter(&sc->sc_slock);
 
        if (write || !FSS_ISVALID(sc)) {
-
-               mutex_exit(&sc->sc_slock);
-
                bp->b_error = (write ? EROFS : ENXIO);
-               bp->b_resid = bp->b_bcount;
-               biodone(bp);
-               return;
+               goto done;
        }
+       /* Check bounds for non-persistent snapshots. */
+       if ((sc->sc_flags & FSS_PERSISTENT) == 0 &&
+           bounds_check_with_mediasize(bp, DEV_BSIZE,
+           btodb(FSS_CLTOB(sc, sc->sc_clcount - 1) + sc->sc_clresid)) <= 0)
+               goto done;
 
        bp->b_rawblkno = bp->b_blkno;
        bufq_put(sc->sc_bufq, bp);
        cv_signal(&sc->sc_work_cv);
 
        mutex_exit(&sc->sc_slock);
+       return;
+
+done:
+       mutex_exit(&sc->sc_slock);
+       bp->b_resid = bp->b_bcount;
+       biodone(bp);
 }
 
 int