Subject: Eliminate toctou by using fstat and always opening with non-blocking i/o
Origin: FILE5_34-17-g54bec4a0 <https://github.com/file/file/commit/FILE5_34-17-g54bec4a0>
Upstream-Author: Christos Zoulas <christos@zoulas.com>
Date: Wed Aug 1 10:07:00 2018 +0000

    Found by coverity.

--- a/src/file.h
+++ b/src/file.h
@@ -597,6 +597,9 @@
 #ifndef O_BINARY
 #define O_BINARY	0
 #endif
+#ifndef O_NONBLOCK
+#define O_NONBLOCK	0
+#endif
 
 #ifndef __cplusplus
 #if defined(__GNUC__) && (__GNUC__ >= 3)
--- a/src/magic.c
+++ b/src/magic.c
@@ -442,18 +442,12 @@
 		else
 			pos = lseek(fd, (off_t)0, SEEK_CUR);
 	} else {
-		int flags = O_RDONLY|O_BINARY;
-		int okstat = stat(inname, &sb) == 0;
-
-		if (okstat && S_ISFIFO(sb.st_mode)) {
-#ifdef O_NONBLOCK
-			flags |= O_NONBLOCK;
-#endif
-			ispipe = 1;
-		}
-
+		int flags = O_RDONLY|O_BINARY|O_NONBLOCK;
 		errno = 0;
 		if ((fd = open(inname, flags)) < 0) {
+			int okstat = fstat(fd, &sb) == 0;
+			if (okstat && S_ISFIFO(sb.st_mode))
+				ispipe = 1;
 #ifdef WIN32
 			/*
 			 * Can't stat, can't open.  It may have been opened in