From: Christos Zoulas <christos@zoulas.com>
Date: Tue, 19 Jan 2016 15:18:02 +0000 (+0000)
Subject: After we map and byteswap, mprotect(2) the magic entries read-only
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b1df343ba4718aa3b682f7315e576cba8cbe6e8a;p=file

After we map and byteswap, mprotect(2) the magic entries read-only
to prevent bugs.
---

diff --git a/src/apprentice.c b/src/apprentice.c
index 1a9a9212..ca82abbe 100644
--- a/src/apprentice.c
+++ b/src/apprentice.c
@@ -32,7 +32,7 @@
 #include "file.h"
 
 #ifndef	lint
-FILE_RCSID("@(#)$File: apprentice.c,v 1.246 2016/01/19 15:09:21 christos Exp $")
+FILE_RCSID("@(#)$File: apprentice.c,v 1.247 2016/01/19 15:18:02 christos Exp $")
 #endif	/* lint */
 
 #include "magic.h"
@@ -2979,6 +2979,12 @@ apprentice_map(struct magic_set *ms, const char *fn)
 
 	if (check_buffer(ms, map, dbname) != 0)
 		goto error;
+#ifdef QUICK
+	if (mprotect(map->p, (size_t)st.st_size, PROT_READ) == -1) {
+		file_error(ms, errno, "cannot mprotect `%s'", dbname);
+		goto error;
+	}
+#endif
 
 	free(dbname);
 	return map;