From a10a207790a27b372d01f580d93f0fa937128c33 Mon Sep 17 00:00:00 2001
From: Pete Batard <pete@akeo.ie>
Date: Tue, 8 Mar 2016 17:28:45 +0000
Subject: [PATCH] [syslinux] fallback to embedded on version match if download
 fails

* Could be useful for current tails user (6.03 based, same as ours)
  who want to create an UFD without downloading files.
* Also improve the buffer overflow check in syslinux/libinstaller/syslxmod.c
---
 src/rufus.c                          |  9 +++++++--
 src/rufus.rc                         | 10 +++++-----
 src/syslinux/libinstaller/syslxmod.c | 10 +++++-----
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/rufus.c b/src/rufus.c
index ef5c507f..3e33c2b8 100644
--- a/src/rufus.c
+++ b/src/rufus.c
@@ -1468,8 +1468,13 @@ static BOOL BootCheck(void)
 							}
 						}
 						if (syslinux_ldlinux_len[i] == 0) {
-							uprintf("Could not download the file - cancelling\n");
-							return FALSE;
+							// If the version matches our embedded one, try to use that as a last ditch effort
+							if (img_report.sl_version == embedded_sl_version[1]) {
+								uprintf("Could not download the file - will try to use embedded %s version instead", img_report.sl_version_str);
+							} else {
+								uprintf("Could not download the file - cancelling\n");
+								return FALSE;
+							}
 						}
 					}
 				}
diff --git a/src/rufus.rc b/src/rufus.rc
index 1871c692..16f49f29 100644
--- a/src/rufus.rc
+++ b/src/rufus.rc
@@ -33,7 +33,7 @@ LANGUAGE LANG_NEUTRAL, SUBLANG_NEUTRAL
 IDD_DIALOG DIALOGEX 12, 12, 242, 376
 STYLE DS_SETFONT | DS_MODALFRAME | DS_CENTER | WS_MINIMIZEBOX | WS_POPUP | WS_CAPTION | WS_SYSMENU
 EXSTYLE WS_EX_ACCEPTFILES
-CAPTION "Rufus 2.8.880"
+CAPTION "Rufus 2.8.881"
 FONT 8, "Segoe UI Symbol", 400, 0, 0x0
 BEGIN
     LTEXT           "Device",IDS_DEVICE_TXT,9,6,200,8
@@ -320,8 +320,8 @@ END
 //
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 2,8,880,0
- PRODUCTVERSION 2,8,880,0
+ FILEVERSION 2,8,881,0
+ PRODUCTVERSION 2,8,881,0
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -338,13 +338,13 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "Akeo Consulting (http://akeo.ie)"
             VALUE "FileDescription", "Rufus"
-            VALUE "FileVersion", "2.8.880"
+            VALUE "FileVersion", "2.8.881"
             VALUE "InternalName", "Rufus"
             VALUE "LegalCopyright", "© 2011-2016 Pete Batard (GPL v3)"
             VALUE "LegalTrademarks", "http://www.gnu.org/copyleft/gpl.html"
             VALUE "OriginalFilename", "rufus.exe"
             VALUE "ProductName", "Rufus"
-            VALUE "ProductVersion", "2.8.880"
+            VALUE "ProductVersion", "2.8.881"
         END
     END
     BLOCK "VarFileInfo"
diff --git a/src/syslinux/libinstaller/syslxmod.c b/src/syslinux/libinstaller/syslxmod.c
index 581f9fce..80d0b430 100644
--- a/src/syslinux/libinstaller/syslxmod.c
+++ b/src/syslinux/libinstaller/syslxmod.c
@@ -122,11 +122,11 @@ int syslinux_patch(const sector_t *sectp, int nsectors,
 	return -1;		/* The actual file is too small for content */
 
     /* Search for LDLINUX_MAGIC to find the patch area */
-    for (wp = (const uint32_t _slimg *)boot_image;
-	 (get_32_sl(wp) != LDLINUX_MAGIC) && (((uintptr_t)wp) < ((uintptr_t)boot_image + boot_image_len));
-	 wp++)
-	;
-    if (((uintptr_t)wp) >= ((uintptr_t)boot_image + boot_image_len))
+    dw = (boot_image_len - sizeof(struct patch_area)) >> 2;
+    for (i = 0, wp = (const uint32_t _slimg *)boot_image;
+	 (i <= dw) && ((get_32_sl(wp) != LDLINUX_MAGIC));
+	 i++, wp++)
+    if (i > dw)	/* Not found */
 	return -1;
     patcharea = (struct patch_area _slimg *)wp;
     epa = slptr(boot_image, &patcharea->epaoffset);