From 2192afd376759f9b0e3720692046baccabf114e9 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Mon, 8 May 2017 15:55:59 -0400
Subject: [PATCH 11/11] put_info(): try to limit bounds of our duplicated
 device path more...

Signed-off-by: Peter Jones <pjones@redhat.com>
---
 linux/libfwup.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/linux/libfwup.c b/linux/libfwup.c
index c14a996..b29a0e5 100644
--- a/linux/libfwup.c
+++ b/linux/libfwup.c
@@ -377,7 +377,10 @@ err:
 		return -1;
 	}
 	/* Make sure sizeof(*info) + dps won't integer overflow */
-	if ((size_t)dps > SSIZE_MAX - sizeof(*info)) {
+	if (((size_t)dps >= SSIZE_MAX - sizeof(*info)) ||
+	    /* Make sure extra hard by just picking an astonishingly large
+	     * value that's merely very very unlikely... */
+	    ((ssize_t)dps > sysconf(_SC_PAGESIZE) * 100)) {
 		efi_error("device path size (%zd) would overflow", dps);
 		errno = EOVERFLOW;
 		return -1;
-- 
2.12.2