Module Name: src
Committed By: riastradh
Date: Sat Feb 5 15:29:50 UTC 2022
Modified Files:
src/sys/kern: kern_ntptime.c
Log Message:
kernel: Avoid arithmetic overflow in ntp_adjtime.
Reported-by: syzbot+f4343a1c91ddfe8bb...@syzkaller.appspotmail.com
To generate a diff of this commit:
cvs rdiff -u -r1.60 -r1.61 src/sys/kern/kern_ntptime.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_ntptime.c
diff -u src/sys/kern/kern_ntptime.c:1.60 src/sys/kern/kern_ntptime.c:1.61
--- src/sys/kern/kern_ntptime.c:1.60 Mon Oct 29 22:02:25 2018
+++ src/sys/kern/kern_ntptime.c Sat Feb 5 15:29:50 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_ntptime.c,v 1.60 2018/10/29 22:02:25 christos Exp $ */
+/* $NetBSD: kern_ntptime.c,v 1.61 2022/02/05 15:29:50 riastradh Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -60,7 +60,7 @@
#include <sys/cdefs.h>
/* __FBSDID("$FreeBSD: src/sys/kern/kern_ntptime.c,v 1.59 2005/05/28 14:34:41 rwatson Exp $"); */
-__KERNEL_RCSID(0, "$NetBSD: kern_ntptime.c,v 1.60 2018/10/29 22:02:25 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_ntptime.c,v 1.61 2022/02/05 15:29:50 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_ntp.h"
@@ -347,7 +347,8 @@ ntp_adjtime1(struct timex *ntv)
if (modes & MOD_CLKA)
time_status &= ~STA_CLK;
if (modes & MOD_FREQUENCY) {
- freq = (ntv->freq * 1000LL) >> 16;
+ freq = MIN(INT32_MAX, MAX(INT32_MIN, ntv->freq));
+ freq = (freq * (int64_t)1000) >> 16;
if (freq > MAXFREQ)
L_LINT(time_freq, MAXFREQ);
else if (freq < -MAXFREQ)
