https://github.com/file/file/commit/35c94dc6acc418f1ad7f6241a6680e5327495793.patch
http://openwall.com/lists/oss-security/2017/09/05/3

The patch is minorly modified to apply to file-5.30

From 35c94dc6acc418f1ad7f6241a6680e5327495793 Mon Sep 17 00:00:00 2001
From: Christos Zoulas <christos@zoulas.com>
Date: Sun, 27 Aug 2017 07:55:02 +0000
Subject: [PATCH] Fix always true condition (Thomas Jarosch)

---
 src/readelf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/readelf.c b/src/readelf.c
index 81451827..5f425c97 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -511,7 +511,7 @@ do_bid_note(struct magic_set *ms, unsigned char *nbuf, uint32_t type,
     size_t noff, size_t doff, int *flags)
 {
 	if (namesz == 4 && strcmp((char *)&nbuf[noff], "GNU") == 0 &&
-	    type == NT_GNU_BUILD_ID && (descsz >= 4 || descsz <= 20)) {
+	    type == NT_GNU_BUILD_ID && (descsz >= 4 && descsz <= 20)) {
 		uint8_t desc[20];
 		const char *btype;
 		uint32_t i;