Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755827AbcCAX4R (ORCPT ); Tue, 1 Mar 2016 18:56:17 -0500 Received: from mail177-1.suw61.mandrillapp.com ([198.2.177.1]:38253 "EHLO mail177-1.suw61.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755755AbcCAX4K (ORCPT ); Tue, 1 Mar 2016 18:56:10 -0500 From: Greg Kroah-Hartman Subject: [PATCH 4.4 153/342] cputime: Prevent 32bit overflow in time[val|spec]_to_cputime() X-Mailer: git-send-email 2.7.2 To: Cc: Greg Kroah-Hartman , , zengtao , Arnd Bergmann , , Thomas Gleixner Message-Id: <20160301234532.914215797@linuxfoundation.org> In-Reply-To: <20160301234527.990448862@linuxfoundation.org> References: <20160301234527.990448862@linuxfoundation.org> X-Report-Abuse: Please forward a copy of this message, including all headers, to abuse@mandrill.com X-Report-Abuse: You can also report abuse here: http://mandrillapp.com/contact/abuse?id=30481620.0f77cb397a59434ba0beeac1fcc72bc6 X-Mandrill-User: md_30481620 Date: Tue, 01 Mar 2016 23:54:34 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1971 Lines: 54 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: zengtao commit 0f26922fe5dc5724b1adbbd54b21bad03590b4f3 upstream. The datatype __kernel_time_t is u32 on 32bit platform, so its subject to overflows in the timeval/timespec to cputime conversion. Currently the following functions are affected: 1. setitimer() 2. timer_create/timer_settime() 3. sys_clock_nanosleep This can happen on MIPS32 and ARM32 with "Full dynticks CPU time accounting" enabled, which is required for CONFIG_NO_HZ_FULL. Enforce u64 conversion to prevent the overflow. Fixes: 31c1fc818715 ("ARM: Kconfig: allow full nohz CPU accounting") Signed-off-by: zengtao Reviewed-by: Arnd Bergmann Cc: Link: http://lkml.kernel.org/r/1454384314-154784-1-git-send-email-prime.zeng@huawei.com Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- include/asm-generic/cputime_nsecs.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/include/asm-generic/cputime_nsecs.h +++ b/include/asm-generic/cputime_nsecs.h @@ -75,7 +75,7 @@ typedef u64 __nocast cputime64_t; */ static inline cputime_t timespec_to_cputime(const struct timespec *val) { - u64 ret = val->tv_sec * NSEC_PER_SEC + val->tv_nsec; + u64 ret = (u64)val->tv_sec * NSEC_PER_SEC + val->tv_nsec; return (__force cputime_t) ret; } static inline void cputime_to_timespec(const cputime_t ct, struct timespec *val) @@ -91,7 +91,8 @@ static inline void cputime_to_timespec(c */ static inline cputime_t timeval_to_cputime(const struct timeval *val) { - u64 ret = val->tv_sec * NSEC_PER_SEC + val->tv_usec * NSEC_PER_USEC; + u64 ret = (u64)val->tv_sec * NSEC_PER_SEC + + val->tv_usec * NSEC_PER_USEC; return (__force cputime_t) ret; } static inline void cputime_to_timeval(const cputime_t ct, struct timeval *val)