Module Name: src
Committed By: kamil
Date: Wed Jul 4 18:15:28 UTC 2018
Modified Files:
src/sys/kern: kern_lwp.c
Log Message:
Avoid undefined behavior in lwp_ctl_free()
Do not left shift signed integer in a way that the signedness bit is
changed.
sys/kern/kern_lwp.c:1892:29, left shift of 1 by 31 places cannot be represented
in type 'int'
Detected with Kernel Undefined Behavior Sanitizer.
Reported by <Harry Pantazis>
To generate a diff of this commit:
cvs rdiff -u -r1.193 -r1.194 src/sys/kern/kern_lwp.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/kern_lwp.c
diff -u src/sys/kern/kern_lwp.c:1.193 src/sys/kern/kern_lwp.c:1.194
--- src/sys/kern/kern_lwp.c:1.193 Wed Jul 4 18:13:01 2018
+++ src/sys/kern/kern_lwp.c Wed Jul 4 18:15:27 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_lwp.c,v 1.193 2018/07/04 18:13:01 kamil Exp $ */
+/* $NetBSD: kern_lwp.c,v 1.194 2018/07/04 18:15:27 kamil Exp $ */
/*-
* Copyright (c) 2001, 2006, 2007, 2008, 2009 The NetBSD Foundation, Inc.
@@ -211,7 +211,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_lwp.c,v 1.193 2018/07/04 18:13:01 kamil Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_lwp.c,v 1.194 2018/07/04 18:15:27 kamil Exp $");
#include "opt_ddb.h"
#include "opt_lockdebug.h"
@@ -1889,7 +1889,7 @@ lwp_ctl_free(lwp_t *l)
mutex_enter(&lp->lp_lock);
lcp->lcp_nfree++;
map = offset >> 5;
- lcp->lcp_bitmap[map] |= (1 << (offset & 31));
+ lcp->lcp_bitmap[map] |= (1U << (offset & 31));
if (lcp->lcp_bitmap[lcp->lcp_rotor] == 0)
lcp->lcp_rotor = map;
if (TAILQ_FIRST(&lp->lp_pages)->lcp_nfree == 0) {
