* [RFC PATCH] posix-cpu-timers: Avoid undefined behaviour in timespec64_to_ns()
@ 2019-02-27 2:06 Xiongfeng Wang
2019-02-27 2:38 ` Deepa Dinamani
0 siblings, 1 reply; 3+ messages in thread
From: Xiongfeng Wang @ 2019-02-27 2:06 UTC (permalink / raw)
To: tglx, deepa.kernel, arnd; +Cc: linux-kernel, wangxiongfeng2
When I ran Syzkaller testsuite, I got the following call trace.
================================================================================
UBSAN: Undefined behaviour in ./include/linux/time64.h:120:27
signed integer overflow:
8243129037239968815 * 1000000000 cannot be represented in type 'long long int'
CPU: 5 PID: 28854 Comm: syz-executor.1 Not tainted 4.19.24 #4
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-project.org 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xca/0x13e lib/dump_stack.c:113
ubsan_epilogue+0xe/0x81 lib/ubsan.c:159
handle_overflow+0x193/0x1e2 lib/ubsan.c:190
timespec64_to_ns include/linux/time64.h:120 [inline]
posix_cpu_timer_set+0x95a/0xb70 kernel/time/posix-cpu-timers.c:687
do_timer_settime+0x198/0x2a0 kernel/time/posix-timers.c:892
__do_sys_timer_settime kernel/time/posix-timers.c:918 [inline]
__se_sys_timer_settime kernel/time/posix-timers.c:904 [inline]
__x64_sys_timer_settime+0x18d/0x260 kernel/time/posix-timers.c:904
do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x462eb9
Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f14e4127c58 EFLAGS: 00000246 ORIG_RAX: 00000000000000df
RAX: ffffffffffffffda RBX: 000000000073bfa0 RCX: 0000000000462eb9
RDX: 0000000020000080 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f14e41286bc
R13: 00000000004c54cc R14: 0000000000704278 R15: 00000000ffffffff
================================================================================
This patch use 'timespec64_to_ktime()' to limit 'tv_sec' to avoid
overflow.
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
---
kernel/time/posix-cpu-timers.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index 80f9552..f7e3929 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -684,7 +684,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
* Install the new reload setting, and
* set up the signal and overrun bookkeeping.
*/
- timer->it.cpu.incr = timespec64_to_ns(&new->it_interval);
+ timer->it.cpu.incr = ktime_to_ns(timespec64_to_ktime(new->it_interval));
timer->it_interval = ns_to_ktime(timer->it.cpu.incr);
/*
--
1.7.12.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [RFC PATCH] posix-cpu-timers: Avoid undefined behaviour in timespec64_to_ns()
2019-02-27 2:06 [RFC PATCH] posix-cpu-timers: Avoid undefined behaviour in timespec64_to_ns() Xiongfeng Wang
@ 2019-02-27 2:38 ` Deepa Dinamani
2019-02-27 3:20 ` Xiongfeng Wang
0 siblings, 1 reply; 3+ messages in thread
From: Deepa Dinamani @ 2019-02-27 2:38 UTC (permalink / raw)
To: Xiongfeng Wang; +Cc: Thomas Gleixner, Arnd Bergmann, Linux Kernel Mailing List
On Tue, Feb 26, 2019 at 6:07 PM Xiongfeng Wang
<wangxiongfeng2@huawei.com> wrote:
>
> When I ran Syzkaller testsuite, I got the following call trace.
> ================================================================================
> UBSAN: Undefined behaviour in ./include/linux/time64.h:120:27
> signed integer overflow:
> 8243129037239968815 * 1000000000 cannot be represented in type 'long long int'
> CPU: 5 PID: 28854 Comm: syz-executor.1 Not tainted 4.19.24 #4
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-project.org 04/01/2014
> Call Trace:
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0xca/0x13e lib/dump_stack.c:113
> ubsan_epilogue+0xe/0x81 lib/ubsan.c:159
> handle_overflow+0x193/0x1e2 lib/ubsan.c:190
> timespec64_to_ns include/linux/time64.h:120 [inline]
> posix_cpu_timer_set+0x95a/0xb70 kernel/time/posix-cpu-timers.c:687
> do_timer_settime+0x198/0x2a0 kernel/time/posix-timers.c:892
> __do_sys_timer_settime kernel/time/posix-timers.c:918 [inline]
> __se_sys_timer_settime kernel/time/posix-timers.c:904 [inline]
> __x64_sys_timer_settime+0x18d/0x260 kernel/time/posix-timers.c:904
> do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x462eb9
> Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007f14e4127c58 EFLAGS: 00000246 ORIG_RAX: 00000000000000df
> RAX: ffffffffffffffda RBX: 000000000073bfa0 RCX: 0000000000462eb9
> RDX: 0000000020000080 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007f14e41286bc
> R13: 00000000004c54cc R14: 0000000000704278 R15: 00000000ffffffff
> ================================================================================
>
> This patch use 'timespec64_to_ktime()' to limit 'tv_sec' to avoid
> overflow.
>
> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
> ---
> kernel/time/posix-cpu-timers.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
> index 80f9552..f7e3929 100644
> --- a/kernel/time/posix-cpu-timers.c
> +++ b/kernel/time/posix-cpu-timers.c
> @@ -684,7 +684,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
> * Install the new reload setting, and
> * set up the signal and overrun bookkeeping.
> */
> - timer->it.cpu.incr = timespec64_to_ns(&new->it_interval);
> + timer->it.cpu.incr = ktime_to_ns(timespec64_to_ktime(new->it_interval));
> timer->it_interval = ns_to_ktime(timer->it.cpu.incr);
>
> /*
This seems like a similar bug as the other one
https://lkml.org/lkml/2019/2/24/214. Maybe it makes sense here also to
do some bounds checking when we get the userspace parameter.
This patch just saturates the value.
-Deepa
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [RFC PATCH] posix-cpu-timers: Avoid undefined behaviour in timespec64_to_ns()
2019-02-27 2:38 ` Deepa Dinamani
@ 2019-02-27 3:20 ` Xiongfeng Wang
0 siblings, 0 replies; 3+ messages in thread
From: Xiongfeng Wang @ 2019-02-27 3:20 UTC (permalink / raw)
To: Deepa Dinamani; +Cc: Thomas Gleixner, Arnd Bergmann, Linux Kernel Mailing List
On 2019/2/27 10:38, Deepa Dinamani wrote:
> On Tue, Feb 26, 2019 at 6:07 PM Xiongfeng Wang
> <wangxiongfeng2@huawei.com> wrote:
>>
>> When I ran Syzkaller testsuite, I got the following call trace.
>> ================================================================================
>> UBSAN: Undefined behaviour in ./include/linux/time64.h:120:27
>> signed integer overflow:
>> 8243129037239968815 * 1000000000 cannot be represented in type 'long long int'
>> CPU: 5 PID: 28854 Comm: syz-executor.1 Not tainted 4.19.24 #4
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-project.org 04/01/2014
>> Call Trace:
>> __dump_stack lib/dump_stack.c:77 [inline]
>> dump_stack+0xca/0x13e lib/dump_stack.c:113
>> ubsan_epilogue+0xe/0x81 lib/ubsan.c:159
>> handle_overflow+0x193/0x1e2 lib/ubsan.c:190
>> timespec64_to_ns include/linux/time64.h:120 [inline]
>> posix_cpu_timer_set+0x95a/0xb70 kernel/time/posix-cpu-timers.c:687
>> do_timer_settime+0x198/0x2a0 kernel/time/posix-timers.c:892
>> __do_sys_timer_settime kernel/time/posix-timers.c:918 [inline]
>> __se_sys_timer_settime kernel/time/posix-timers.c:904 [inline]
>> __x64_sys_timer_settime+0x18d/0x260 kernel/time/posix-timers.c:904
>> do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
>> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>> RIP: 0033:0x462eb9
>> Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
>> RSP: 002b:00007f14e4127c58 EFLAGS: 00000246 ORIG_RAX: 00000000000000df
>> RAX: ffffffffffffffda RBX: 000000000073bfa0 RCX: 0000000000462eb9
>> RDX: 0000000020000080 RSI: 0000000000000000 RDI: 0000000000000000
>> RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
>> R10: 0000000000000000 R11: 0000000000000246 R12: 00007f14e41286bc
>> R13: 00000000004c54cc R14: 0000000000704278 R15: 00000000ffffffff
>> ================================================================================
>>
>> This patch use 'timespec64_to_ktime()' to limit 'tv_sec' to avoid
>> overflow.
>>
>> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
>> ---
>> kernel/time/posix-cpu-timers.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
>> index 80f9552..f7e3929 100644
>> --- a/kernel/time/posix-cpu-timers.c
>> +++ b/kernel/time/posix-cpu-timers.c
>> @@ -684,7 +684,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
>> * Install the new reload setting, and
>> * set up the signal and overrun bookkeeping.
>> */
>> - timer->it.cpu.incr = timespec64_to_ns(&new->it_interval);
>> + timer->it.cpu.incr = ktime_to_ns(timespec64_to_ktime(new->it_interval));
>> timer->it_interval = ns_to_ktime(timer->it.cpu.incr);
>>
>> /*
>
> This seems like a similar bug as the other one
> https://lkml.org/lkml/2019/2/24/214. Maybe it makes sense here also to
> do some bounds checking when we get the userspace parameter.
> This patch just saturates the value.
Thanks for your advice. I will send another version.
Thanks,
Xiongfeng
>
> -Deepa
>
> .
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-02-27 3:21 UTC | newest]
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2019-02-27 2:06 [RFC PATCH] posix-cpu-timers: Avoid undefined behaviour in timespec64_to_ns() Xiongfeng Wang
2019-02-27 2:38 ` Deepa Dinamani
2019-02-27 3:20 ` Xiongfeng Wang
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