From 3843d88ca8cb214593db38aa2d8ab548e3592426 Mon Sep 17 00:00:00 2001
From: Mark Johnston <markj@FreeBSD.org>
Date: Tue, 26 Feb 2019 18:30:51 +0000
Subject: [PATCH] Add a missing return statement to g_concat_kernel_dump().

The error occurs when upper layers attempt an out-of-bounds write.

Submitted by:	Noah Bergbauer <noah.bergbauer@tum.de>
MFC after:	1 week
---
 sys/geom/concat/g_concat.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sys/geom/concat/g_concat.c b/sys/geom/concat/g_concat.c
index df30c379ed92..a0a95b85aba0 100644
--- a/sys/geom/concat/g_concat.c
+++ b/sys/geom/concat/g_concat.c
@@ -238,8 +238,10 @@ g_concat_kernel_dump(struct bio *bp)
 		    sc->sc_disks[i].d_end > gkd->offset)
 			break;
 	}
-	if (i == sc->sc_ndisks)
+	if (i == sc->sc_ndisks) {
 		g_io_deliver(bp, EOPNOTSUPP);
+		return;
+	}
 	disk = &sc->sc_disks[i];
 	gkd->offset -= disk->d_start;
 	if (gkd->length > disk->d_end - disk->d_start - gkd->offset)