File xkbcomp-fix-crash-when-parsing-an-xkb_geometry-secti.patch of Package libxkbcommon.31860

From 917636b1d0d70205a13f89062b95e3a0fc31d4ff Mon Sep 17 00:00:00 2001
From: Ran Benita <ran234@gmail.com>
Date: Sun, 11 Mar 2018 17:07:06 +0200
Subject: [PATCH] xkbcomp: fix crash when parsing an xkb_geometry section
Git-commit: 917636b1d0d70205a13f89062b95e3a0fc31d4ff
Patch-mainline: xkbcommon-0.8.1
References: CVE-2018-15855

xkb_geometry sections are ignored; previously the had done so by
returning NULL for the section's XkbFile, however some sections of the
code do not expect this. Instead, create an XkbFile for it, it will
never be processes and discarded later.

Caught with the afl fuzzer.

Signed-off-by: Ran Benita <ran234@gmail.com>

---
 src/xkbcomp/keymap.c | 9 +++++++--
 src/xkbcomp/parser.y | 9 +--------
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/src/xkbcomp/keymap.c b/src/xkbcomp/keymap.c
index 45098c2..e95e50c 100644
--- a/src/xkbcomp/keymap.c
+++ b/src/xkbcomp/keymap.c
@@ -241,8 +241,13 @@ CompileKeymap(XkbFile *file, struct xkb_keymap *keymap, enum merge_mode merge)
          file = (XkbFile *) file->common.next) {
         if (file->file_type < FIRST_KEYMAP_FILE_TYPE ||
             file->file_type > LAST_KEYMAP_FILE_TYPE) {
-            log_err(ctx, "Cannot define %s in a keymap file\n",
-                    xkb_file_type_to_string(file->file_type));
+            if (file->file_type == FILE_TYPE_GEOMETRY) {
+                log_vrb(ctx, 1,
+                        "Geometry sections are not supported; ignoring\n");
+            } else {
+                log_err(ctx, "Cannot define %s in a keymap file\n",
+                        xkb_file_type_to_string(file->file_type));
+            }
             continue;
         }
 
diff --git a/src/xkbcomp/parser.y b/src/xkbcomp/parser.y
index d15d24b..b555bc2 100644
--- a/src/xkbcomp/parser.y
+++ b/src/xkbcomp/parser.y
@@ -273,14 +273,7 @@ XkbMapConfig    :       OptFlags FileType OptMapName OBRACE
                             DeclList
                         CBRACE SEMI
                         {
-                            if ($2 == FILE_TYPE_GEOMETRY) {
-                                free($3);
-                                FreeStmt($5);
-                                $$ = NULL;
-                            }
-                            else {
-                                $$ = XkbFileCreate($2, $3, $5, $1);
-                            }
+                            $$ = XkbFileCreate($2, $3, $5, $1);
                         }
                 ;
 
-- 
2.35.3