kbuild: scripts/basic/fixdep segfault on pathological string-o-death

build scripts: fixdep blows segfault on string CONFIG_MODULE seen

The string "CONFIG_MODULE" appearing anywhere in a source file causes
fixdep to segfault.  This string appeared in the wild in the current
mISDN sources (I think they meant CONFIG_MODULES).  But it shouldn't
segfault (esp as CONFIG_MODULE appeared in a quoted string).

Signed-off-by: Andy Green <andy@warmcat.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c
index 6bc7e7cfccf6..8912c0f5460b 100644
--- a/scripts/basic/fixdep.c
+++ b/scripts/basic/fixdep.c
@@ -249,6 +249,8 @@ void parse_config_file(char *map, size_t len)
         found:
                 if (!memcmp(q - 7, "_MODULE", 7))
                         q -= 7;
+                if( (q-p-7) < 0 )
+                        continue;
                 use_config(p+7, q-p-7);
         }
 }