From: Dmitry V. Levin <ldv@altlinux.org>
Date: Fri, 25 Mar 2016 23:48:48 +0000 (+0000)
Subject: Fix decoding of device numbers in mknod and mknodat syscalls
X-Git-Tag: v4.12~492
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9d91928320c8c5a2472a64d431074238a5213eb9;p=strace

Fix decoding of device numbers in mknod and mknodat syscalls

* mknod.c (decode_mknod): Treat device number argument as unsigned int.
* tests/mknod.c: Include <sys/sysmacros.h> or <sys/mkdev.h>
for definition of makedev macro.
(main): Add a check for a character special file.
---

diff --git a/mknod.c b/mknod.c
index 14d9ddd7..d78fa07f 100644
--- a/mknod.c
+++ b/mknod.c
@@ -48,15 +48,15 @@ static void
 decode_mknod(struct tcb *tcp, int offset)
 {
 	int mode = tcp->u_arg[offset + 1];
+	unsigned int dev;
 
 	printpath(tcp, tcp->u_arg[offset]);
 	tprintf(", %s", sprintmode(mode));
 	switch (mode & S_IFMT) {
 	case S_IFCHR:
 	case S_IFBLK:
-		tprintf(", makedev(%lu, %lu)",
-			(unsigned long) major(tcp->u_arg[offset + 2]),
-			(unsigned long) minor(tcp->u_arg[offset + 2]));
+		dev = tcp->u_arg[offset + 2];
+		tprintf(", makedev(%u, %u)", major(dev), minor(dev));
 		break;
 	}
 }
diff --git a/tests/mknod.c b/tests/mknod.c
index 7e80582e..48367fed 100644
--- a/tests/mknod.c
+++ b/tests/mknod.c
@@ -8,6 +8,13 @@
 # include <sys/stat.h>
 # include <unistd.h>
 
+# ifdef MAJOR_IN_SYSMACROS
+#  include <sys/sysmacros.h>
+# endif
+# ifdef MAJOR_IN_MKDEV
+#  include <sys/mkdev.h>
+# endif
+
 # define TMP_FILE "mknod"
 
 int
@@ -18,6 +25,13 @@ main(void)
 	       TMP_FILE, rc,
 	       errno == ENOSYS ? "ENOSYS" : "EEXIST");
 
+	const unsigned long dev =
+		(unsigned long) 0xdeadbeef00000000 | makedev(1, 7);
+	rc = syscall(__NR_mknod, TMP_FILE, S_IFCHR | 0400, dev);
+	printf("mknod(\"%s\", S_IFCHR|0400, makedev(1, 7)) = %d %s (%m)\n",
+	       TMP_FILE, rc,
+	       errno == ENOSYS ? "ENOSYS" : "EEXIST");
+
 	puts("+++ exited with 0 +++");
 	return 0;
 }