1From 1641d74e16f9d1ca35ba1a87ee4a0bf3afa48e72 Mon Sep 17 00:00:00 2001
2From: Darren Kenny <darren.kenny@oracle.com>
3Date: Fri, 4 Dec 2020 15:04:28 +0000
4Subject: [PATCH] util/glue-efi: Fix incorrect use of a possibly negative value
5
6It is possible for the ftell() function to return a negative value,
7although it is fairly unlikely here, we should be checking for
8a negative value before we assign it to an unsigned value.
9
10Fixes: CID 73744
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/glue-efi.c | 14 ++++++++++++--
17 1 file changed, 12 insertions(+), 2 deletions(-)
18
19diff --git a/util/glue-efi.c b/util/glue-efi.c
20index 68f5316..de0fa6d 100644
21--- a/util/glue-efi.c
22+++ b/util/glue-efi.c
23@@ -39,13 +39,23 @@ write_fat (FILE *in32, FILE *in64, FILE *out, const char *out_filename,
24   struct grub_macho_fat_header head;
25   struct grub_macho_fat_arch arch32, arch64;
26   grub_uint32_t size32, size64;
27+  long size;
28   char *buf;
29
30   fseek (in32, 0, SEEK_END);
31-  size32 = ftell (in32);
32+  size = ftell (in32);
33+  if (size < 0)
34+    grub_util_error ("cannot get end of input file '%s': %s",
35+		     name32, strerror (errno));
36+  size32 = (grub_uint32_t) size;
37   fseek (in32, 0, SEEK_SET);
38+
39   fseek (in64, 0, SEEK_END);
40-  size64 = ftell (in64);
41+  size = ftell (in64);
42+  if (size < 0)
43+    grub_util_error ("cannot get end of input file '%s': %s",
44+		     name64, strerror (errno));
45+  size64 = (grub_uint64_t) size;
46   fseek (in64, 0, SEEK_SET);
47
48   head.magic = grub_cpu_to_le32_compile_time (GRUB_MACHO_FAT_EFI_MAGIC);
49--
502.14.2
51
52