1From 5dc41edc4eba259c6043ae7698c245ec1baaacc6 Mon Sep 17 00:00:00 2001
2From: Darren Kenny <darren.kenny@oracle.com>
3Date: Thu, 5 Nov 2020 14:33:50 +0000
4Subject: [PATCH] util/grub-editenv: Fix incorrect casting of a signed value
5
6The return value of ftell() may be negative (-1) on error. While it is
7probably unlikely to occur, we should not blindly cast to an unsigned
8value without first testing that it is not negative.
9
10Fixes: CID 73856
11
12Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
13Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
14Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
15---
16 util/grub-editenv.c | 8 +++++++-
17 1 file changed, 7 insertions(+), 1 deletion(-)
18
19diff --git a/util/grub-editenv.c b/util/grub-editenv.c
20index f3662c9..db6f187 100644
21--- a/util/grub-editenv.c
22+++ b/util/grub-editenv.c
23@@ -125,6 +125,7 @@ open_envblk_file (const char *name)
24 {
25   FILE *fp;
26   char *buf;
27+  long loc;
28   size_t size;
29   grub_envblk_t envblk;
30
31@@ -143,7 +144,12 @@ open_envblk_file (const char *name)
32     grub_util_error (_("cannot seek `%s': %s"), name,
33 		     strerror (errno));
34
35-  size = (size_t) ftell (fp);
36+  loc = ftell (fp);
37+  if (loc < 0)
38+    grub_util_error (_("cannot get file location `%s': %s"), name,
39+		     strerror (errno));
40+
41+  size = (size_t) loc;
42
43   if (fseek (fp, 0, SEEK_SET) < 0)
44     grub_util_error (_("cannot seek `%s': %s"), name,
45--
462.14.2
47
48