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[net] can: isotp: add result check for wait_event_interruptible()

Message ID 20210918092819.156291-1-william.xuanziyang@huawei.com (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
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Series [net] can: isotp: add result check for wait_event_interruptible() | expand

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Commit Message

Ziyang Xuan (William) Sept. 18, 2021, 9:28 a.m. UTC
Using wait_event_interruptible() to wait for complete transmission,
but do not check the result of wait_event_interruptible() which can
be interrupted. It will result in tx buffer has multiple accessers
and the later process interferes with the previous process.

Following is one of the problems reported by syzbot.

=============================================================
WARNING: CPU: 0 PID: 0 at net/can/isotp.c:840 isotp_tx_timer_handler+0x2e0/0x4c0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.13.0-rc7+ #68
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014
RIP: 0010:isotp_tx_timer_handler+0x2e0/0x4c0
Call Trace:
 <IRQ>
 ? isotp_setsockopt+0x390/0x390
 __hrtimer_run_queues+0xb8/0x610
 hrtimer_run_softirq+0x91/0xd0
 ? rcu_read_lock_sched_held+0x4d/0x80
 __do_softirq+0xe8/0x553
 irq_exit_rcu+0xf8/0x100
 sysvec_apic_timer_interrupt+0x9e/0xc0
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20

Add result check for wait_event_interruptible() in isotp_sendmsg()
to avoid multiple accessers for tx buffer.

Reported-by: syzbot+78bab6958a614b0c80b9@syzkaller.appspotmail.com
Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
---
 net/can/isotp.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Ziyang Xuan (William) Sept. 27, 2021, 1:39 a.m. UTC | #1
> Using wait_event_interruptible() to wait for complete transmission,
> but do not check the result of wait_event_interruptible() which can
> be interrupted. It will result in tx buffer has multiple accessers
> and the later process interferes with the previous process.
> 
> Following is one of the problems reported by syzbot.
> 
> =============================================================
> WARNING: CPU: 0 PID: 0 at net/can/isotp.c:840 isotp_tx_timer_handler+0x2e0/0x4c0
> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.13.0-rc7+ #68
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014
> RIP: 0010:isotp_tx_timer_handler+0x2e0/0x4c0
> Call Trace:
>  <IRQ>
>  ? isotp_setsockopt+0x390/0x390
>  __hrtimer_run_queues+0xb8/0x610
>  hrtimer_run_softirq+0x91/0xd0
>  ? rcu_read_lock_sched_held+0x4d/0x80
>  __do_softirq+0xe8/0x553
>  irq_exit_rcu+0xf8/0x100
>  sysvec_apic_timer_interrupt+0x9e/0xc0
>  </IRQ>
>  asm_sysvec_apic_timer_interrupt+0x12/0x20
> 
> Add result check for wait_event_interruptible() in isotp_sendmsg()
> to avoid multiple accessers for tx buffer.
> 
> Reported-by: syzbot+78bab6958a614b0c80b9@syzkaller.appspotmail.com
> Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>

Hi Oliver,
I send a new patch with this problem, ignore this patch please.

Thank you!
Oliver Hartkopp Sept. 27, 2021, 11:32 a.m. UTC | #2
On 27.09.21 03:39, Ziyang Xuan (William) wrote:
>> Using wait_event_interruptible() to wait for complete transmission,
>> but do not check the result of wait_event_interruptible() which can
>> be interrupted. It will result in tx buffer has multiple accessers
>> and the later process interferes with the previous process.
>>
>> Following is one of the problems reported by syzbot.
>>
>> =============================================================
>> WARNING: CPU: 0 PID: 0 at net/can/isotp.c:840 isotp_tx_timer_handler+0x2e0/0x4c0
>> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.13.0-rc7+ #68
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014
>> RIP: 0010:isotp_tx_timer_handler+0x2e0/0x4c0
>> Call Trace:
>>   <IRQ>
>>   ? isotp_setsockopt+0x390/0x390
>>   __hrtimer_run_queues+0xb8/0x610
>>   hrtimer_run_softirq+0x91/0xd0
>>   ? rcu_read_lock_sched_held+0x4d/0x80
>>   __do_softirq+0xe8/0x553
>>   irq_exit_rcu+0xf8/0x100
>>   sysvec_apic_timer_interrupt+0x9e/0xc0
>>   </IRQ>
>>   asm_sysvec_apic_timer_interrupt+0x12/0x20
>>
>> Add result check for wait_event_interruptible() in isotp_sendmsg()
>> to avoid multiple accessers for tx buffer.
>>
>> Reported-by: syzbot+78bab6958a614b0c80b9@syzkaller.appspotmail.com
>> Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
>> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
> 
> Hi Oliver,
> I send a new patch with this problem, ignore this patch please.
> 
> Thank you!
> 

I was still pondering on this patch ;-)

But I'll take a look on the update now.

Thanks & best regards,
Oliver
diff mbox series

Patch

diff --git a/net/can/isotp.c b/net/can/isotp.c
index caaa532ece94..2ac29c2b2ca6 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -865,7 +865,9 @@  static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 			return -EAGAIN;
 
 		/* wait for complete transmission of current pdu */
-		wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
+		err = wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
+		if (err)
+			return err;
 	}
 
 	if (!size || size > MAX_MSG_LENGTH)