* [PATCH] net:sched fix array-index-out-of-bounds in taprio_change
@ 2021-08-11 5:10 tcs.kernel
2021-08-11 7:44 ` Eric Dumazet
2021-08-12 17:53 ` Jakub Kicinski
0 siblings, 2 replies; 9+ messages in thread
From: tcs.kernel @ 2021-08-11 5:10 UTC (permalink / raw)
To: vinicius.gomes, jhs, xiyou.wangcong, jiri, davem, kuba, netdev
Cc: Haimin Zhang
From: Haimin Zhang <tcs_kernel@tencent.com>
syzbot report an array-index-out-of-bounds in taprio_change
index 16 is out of range for type '__u16 [16]'
that's because mqprio->num_tc is lager than TC_MAX_QUEUE,so we check
the return value of netdev_set_num_tc.
Reported-by: syzbot+2b3e5fb6c7ef285a94f6@syzkaller.appspotmail.com
Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com>
---
net/sched/sch_taprio.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 9c79374..1ab2fc9 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -1513,7 +1513,9 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
taprio_set_picos_per_byte(dev, q);
if (mqprio) {
- netdev_set_num_tc(dev, mqprio->num_tc);
+ err = netdev_set_num_tc(dev, mqprio->num_tc);
+ if (err)
+ goto free_sched;
for (i = 0; i < mqprio->num_tc; i++)
netdev_set_tc_queue(dev, i,
mqprio->count[i],
--
1.8.3.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH] net:sched fix array-index-out-of-bounds in taprio_change
2021-08-11 5:10 [PATCH] net:sched fix array-index-out-of-bounds in taprio_change tcs.kernel
@ 2021-08-11 7:44 ` Eric Dumazet
2021-08-11 8:30 ` Pavel Skripkin
2021-08-11 8:36 ` Haimin Zhang
2021-08-12 17:53 ` Jakub Kicinski
1 sibling, 2 replies; 9+ messages in thread
From: Eric Dumazet @ 2021-08-11 7:44 UTC (permalink / raw)
To: tcs.kernel, vinicius.gomes, jhs, xiyou.wangcong, jiri, davem,
kuba, netdev
Cc: Haimin Zhang
On 8/11/21 7:10 AM, tcs.kernel@gmail.com wrote:
> From: Haimin Zhang <tcs_kernel@tencent.com>
>
> syzbot report an array-index-out-of-bounds in taprio_change
> index 16 is out of range for type '__u16 [16]'
> that's because mqprio->num_tc is lager than TC_MAX_QUEUE,so we check
> the return value of netdev_set_num_tc.
>
> Reported-by: syzbot+2b3e5fb6c7ef285a94f6@syzkaller.appspotmail.com
> Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com>
> ---
> net/sched/sch_taprio.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
> index 9c79374..1ab2fc9 100644
> --- a/net/sched/sch_taprio.c
> +++ b/net/sched/sch_taprio.c
> @@ -1513,7 +1513,9 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
> taprio_set_picos_per_byte(dev, q);
>
> if (mqprio) {
> - netdev_set_num_tc(dev, mqprio->num_tc);
> + err = netdev_set_num_tc(dev, mqprio->num_tc);
> + if (err)
> + goto free_sched;
> for (i = 0; i < mqprio->num_tc; i++)
> netdev_set_tc_queue(dev, i,
> mqprio->count[i],
>
When was the bug added ?
Hint: Please provide a Fixes: tag
taprio_parse_mqprio_opt() already checks :
/* Verify num_tc is not out of max range */
if (qopt->num_tc > TC_MAX_QUEUE) {
NL_SET_ERR_MSG(extack, "Number of traffic classes is outside valid range");
return -EINVAL;
}
So what is happening exactly ?
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] net:sched fix array-index-out-of-bounds in taprio_change
2021-08-11 7:44 ` Eric Dumazet
@ 2021-08-11 8:30 ` Pavel Skripkin
2021-08-11 8:35 ` Pavel Skripkin
2021-08-11 8:36 ` Haimin Zhang
1 sibling, 1 reply; 9+ messages in thread
From: Pavel Skripkin @ 2021-08-11 8:30 UTC (permalink / raw)
To: Eric Dumazet, tcs.kernel, vinicius.gomes, jhs, xiyou.wangcong,
jiri, davem, kuba, netdev
Cc: Haimin Zhang
On 8/11/21 10:44 AM, Eric Dumazet wrote:
>
>
> On 8/11/21 7:10 AM, tcs.kernel@gmail.com wrote:
>> From: Haimin Zhang <tcs_kernel@tencent.com>
>>
>> syzbot report an array-index-out-of-bounds in taprio_change
>> index 16 is out of range for type '__u16 [16]'
>> that's because mqprio->num_tc is lager than TC_MAX_QUEUE,so we check
>> the return value of netdev_set_num_tc.
>>
>> Reported-by: syzbot+2b3e5fb6c7ef285a94f6@syzkaller.appspotmail.com
>> Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com>
>> ---
>> net/sched/sch_taprio.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
>> index 9c79374..1ab2fc9 100644
>> --- a/net/sched/sch_taprio.c
>> +++ b/net/sched/sch_taprio.c
>> @@ -1513,7 +1513,9 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
>> taprio_set_picos_per_byte(dev, q);
>>
>> if (mqprio) {
>> - netdev_set_num_tc(dev, mqprio->num_tc);
>> + err = netdev_set_num_tc(dev, mqprio->num_tc);
>> + if (err)
>> + goto free_sched;
>> for (i = 0; i < mqprio->num_tc; i++)
>> netdev_set_tc_queue(dev, i,
>> mqprio->count[i],
>>
>
> When was the bug added ?
>
> Hint: Please provide a Fixes: tag
>
> taprio_parse_mqprio_opt() already checks :
>
> /* Verify num_tc is not out of max range */
> if (qopt->num_tc > TC_MAX_QUEUE) {
> NL_SET_ERR_MSG(extack, "Number of traffic classes is outside valid range");
> return -EINVAL;
> }
>
> So what is happening exactly ?
>
>
Hi, Eric!
I've looked into this bug, but I decided to write a reproducer for it
first. Unfortunately, I didn't finish it yesterday, but I have an idea
about what happened:
taprio_parse_mqprio_opt() may return 0 before qopt->num_tc check:
/* If num_tc is already set, it means that the user already
* configured the mqprio part
*/
if (dev->num_tc)
return 0;
Then taprio_mqprio_cmp() fails here:
if (!mqprio || mqprio->num_tc != dev->num_tc)
return -1;
That's why we won't get shift-out-of-bound in taprio_mqprio_cmp().
And finally taprio_change() gets to buggy for with wrong mqprio->num_tc.
I don't know how to reproduce it, but I'll try to finish my reproducer
this evening.
Does above makes any sense?
With regards,
Pavel Skripkin
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] net:sched fix array-index-out-of-bounds in taprio_change
2021-08-11 8:30 ` Pavel Skripkin
@ 2021-08-11 8:35 ` Pavel Skripkin
0 siblings, 0 replies; 9+ messages in thread
From: Pavel Skripkin @ 2021-08-11 8:35 UTC (permalink / raw)
To: Eric Dumazet, tcs.kernel, vinicius.gomes, jhs, xiyou.wangcong,
jiri, davem, kuba, netdev
Cc: Haimin Zhang
On 8/11/21 11:30 AM, Pavel Skripkin wrote:
> On 8/11/21 10:44 AM, Eric Dumazet wrote:
>>
>>
>> On 8/11/21 7:10 AM, tcs.kernel@gmail.com wrote:
>>> From: Haimin Zhang <tcs_kernel@tencent.com>
>>>
>>> syzbot report an array-index-out-of-bounds in taprio_change
>>> index 16 is out of range for type '__u16 [16]'
>>> that's because mqprio->num_tc is lager than TC_MAX_QUEUE,so we check
>>> the return value of netdev_set_num_tc.
>>>
>>> Reported-by: syzbot+2b3e5fb6c7ef285a94f6@syzkaller.appspotmail.com
>>> Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com>
>>> ---
>>> net/sched/sch_taprio.c | 4 +++-
>>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
>>> index 9c79374..1ab2fc9 100644
>>> --- a/net/sched/sch_taprio.c
>>> +++ b/net/sched/sch_taprio.c
>>> @@ -1513,7 +1513,9 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
>>> taprio_set_picos_per_byte(dev, q);
>>>
>>> if (mqprio) {
>>> - netdev_set_num_tc(dev, mqprio->num_tc);
>>> + err = netdev_set_num_tc(dev, mqprio->num_tc);
>>> + if (err)
>>> + goto free_sched;
>>> for (i = 0; i < mqprio->num_tc; i++)
>>> netdev_set_tc_queue(dev, i,
>>> mqprio->count[i],
>>>
>>
>> When was the bug added ?
>>
>> Hint: Please provide a Fixes: tag
>>
>> taprio_parse_mqprio_opt() already checks :
>>
>> /* Verify num_tc is not out of max range */
>> if (qopt->num_tc > TC_MAX_QUEUE) {
>> NL_SET_ERR_MSG(extack, "Number of traffic classes is outside valid range");
>> return -EINVAL;
>> }
>>
>> So what is happening exactly ?
>>
>>
>
> Hi, Eric!
>
> I've looked into this bug, but I decided to write a reproducer for it
> first. Unfortunately, I didn't finish it yesterday, but I have an idea
> about what happened:
>
> taprio_parse_mqprio_opt() may return 0 before qopt->num_tc check:
>
> /* If num_tc is already set, it means that the user already
> * configured the mqprio part
> */
> if (dev->num_tc)
> return 0;
>
> Then taprio_mqprio_cmp() fails here:
>
> if (!mqprio || mqprio->num_tc != dev->num_tc)
> return -1;
>
> That's why we won't get shift-out-of-bound in taprio_mqprio_cmp().
^^^^^^^^^^^^^^^^^
array-index-out-of-bounds
Sorry for confusion
With regards,
Pavel Skripkin
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] net:sched fix array-index-out-of-bounds in taprio_change
2021-08-11 7:44 ` Eric Dumazet
2021-08-11 8:30 ` Pavel Skripkin
@ 2021-08-11 8:36 ` Haimin Zhang
2021-08-30 2:09 ` Haimin Zhang
1 sibling, 1 reply; 9+ messages in thread
From: Haimin Zhang @ 2021-08-11 8:36 UTC (permalink / raw)
To: Eric Dumazet, vinicius.gomes, jhs, xiyou.wangcong, jiri, davem,
kuba, netdev
Cc: Haimin Zhang
在 2021/8/11 15:44, Eric Dumazet 写道:
>
>
> On 8/11/21 7:10 AM, tcs.kernel@gmail.com wrote:
>> From: Haimin Zhang <tcs_kernel@tencent.com>
>>
>> syzbot report an array-index-out-of-bounds in taprio_change
>> index 16 is out of range for type '__u16 [16]'
>> that's because mqprio->num_tc is lager than TC_MAX_QUEUE,so we check
>> the return value of netdev_set_num_tc.
>>
>> Reported-by: syzbot+2b3e5fb6c7ef285a94f6@syzkaller.appspotmail.com
>> Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com>
>> ---
>> net/sched/sch_taprio.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
>> index 9c79374..1ab2fc9 100644
>> --- a/net/sched/sch_taprio.c
>> +++ b/net/sched/sch_taprio.c
>> @@ -1513,7 +1513,9 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
>> taprio_set_picos_per_byte(dev, q);
>>
>> if (mqprio) {
>> - netdev_set_num_tc(dev, mqprio->num_tc);
>> + err = netdev_set_num_tc(dev, mqprio->num_tc);
>> + if (err)
>> + goto free_sched;
>> for (i = 0; i < mqprio->num_tc; i++)
>> netdev_set_tc_queue(dev, i,
>> mqprio->count[i],
>>
>
> When was the bug added ?
>
> Hint: Please provide a Fixes: tag
>
> taprio_parse_mqprio_opt() already checks :
>
> /* Verify num_tc is not out of max range */
> if (qopt->num_tc > TC_MAX_QUEUE) {
> NL_SET_ERR_MSG(extack, "Number of traffic classes is outside valid range");
> return -EINVAL;
> }
>
> So what is happening exactly ?
>
>
>
>
syzkaller reported this problem,the log shows mqprio->count[16] is accessed.
here is the log
https://syzkaller.appspot.com/bug?id=3a3677d4e7539ec5e671a81e32882ad40b5f7b64
the added check logic is hurtlessness,and netdev_set_num_tc does have a
return value.
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] net:sched fix array-index-out-of-bounds in taprio_change
2021-08-11 8:36 ` Haimin Zhang
@ 2021-08-30 2:09 ` Haimin Zhang
2021-08-30 16:10 ` Jakub Kicinski
0 siblings, 1 reply; 9+ messages in thread
From: Haimin Zhang @ 2021-08-30 2:09 UTC (permalink / raw)
To: Eric Dumazet, vinicius.gomes, jhs, xiyou.wangcong, jiri, davem,
kuba, netdev
Cc: Haimin Zhang
hi，i wonder to know what‘s going on with this patch ?
are you plannig to merge it ?
在 2021/8/11 16:36, Haimin Zhang 写道:
>
>
> 在 2021/8/11 15:44, Eric Dumazet 写道:
>>
>>
>> On 8/11/21 7:10 AM, tcs.kernel@gmail.com wrote:
>>> From: Haimin Zhang <tcs_kernel@tencent.com>
>>>
>>> syzbot report an array-index-out-of-bounds in taprio_change
>>> index 16 is out of range for type '__u16 [16]'
>>> that's because mqprio->num_tc is lager than TC_MAX_QUEUE,so we check
>>> the return value of netdev_set_num_tc.
>>>
>>> Reported-by: syzbot+2b3e5fb6c7ef285a94f6@syzkaller.appspotmail.com
>>> Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com>
>>> ---
>>> net/sched/sch_taprio.c | 4 +++-
>>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
>>> index 9c79374..1ab2fc9 100644
>>> --- a/net/sched/sch_taprio.c
>>> +++ b/net/sched/sch_taprio.c
>>> @@ -1513,7 +1513,9 @@ static int taprio_change(struct Qdisc *sch,
>>> struct nlattr *opt,
>>> taprio_set_picos_per_byte(dev, q);
>>> if (mqprio) {
>>> - netdev_set_num_tc(dev, mqprio->num_tc);
>>> + err = netdev_set_num_tc(dev, mqprio->num_tc);
>>> + if (err)
>>> + goto free_sched;
>>> for (i = 0; i < mqprio->num_tc; i++)
>>> netdev_set_tc_queue(dev, i,
>>> mqprio->count[i],
>>>
>>
>> When was the bug added ?
>>
>> Hint: Please provide a Fixes: tag
>>
>> taprio_parse_mqprio_opt() already checks :
>>
>> /* Verify num_tc is not out of max range */
>> if (qopt->num_tc > TC_MAX_QUEUE) {
>> NL_SET_ERR_MSG(extack, "Number of traffic classes is outside
>> valid range");
>> return -EINVAL;
>> }
>>
>> So what is happening exactly ?
>>
>>
>>
>>
> syzkaller reported this problem,the log shows mqprio->count[16] is
> accessed.
> here is the log
> https://syzkaller.appspot.com/bug?id=3a3677d4e7539ec5e671a81e32882ad40b5f7b64
>
>
> the added check logic is hurtlessness,and netdev_set_num_tc does have a
> return value.
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] net:sched fix array-index-out-of-bounds in taprio_change
2021-08-30 2:09 ` Haimin Zhang
@ 2021-08-30 16:10 ` Jakub Kicinski
0 siblings, 0 replies; 9+ messages in thread
From: Jakub Kicinski @ 2021-08-30 16:10 UTC (permalink / raw)
To: Haimin Zhang
Cc: Eric Dumazet, vinicius.gomes, jhs, xiyou.wangcong, jiri, davem,
netdev, Haimin Zhang
On Mon, 30 Aug 2021 10:09:38 +0800 Haimin Zhang wrote:
> hi，i wonder to know what‘s going on with this patch ?
> are you plannig to merge it ?
Please don't top post. As I told you I think that fix belongs in
taprio_parse_mqprio_opt() which is validating inputs, not in the
middle of the code applying the changes.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] net:sched fix array-index-out-of-bounds in taprio_change
2021-08-11 5:10 [PATCH] net:sched fix array-index-out-of-bounds in taprio_change tcs.kernel
2021-08-11 7:44 ` Eric Dumazet
@ 2021-08-12 17:53 ` Jakub Kicinski
1 sibling, 0 replies; 9+ messages in thread
From: Jakub Kicinski @ 2021-08-12 17:53 UTC (permalink / raw)
To: tcs.kernel, vinicius.gomes
Cc: jhs, xiyou.wangcong, jiri, davem, netdev, Haimin Zhang
On Wed, 11 Aug 2021 13:10:09 +0800 tcs.kernel@gmail.com wrote:
> From: Haimin Zhang <tcs_kernel@tencent.com>
>
> syzbot report an array-index-out-of-bounds in taprio_change
> index 16 is out of range for type '__u16 [16]'
> that's because mqprio->num_tc is lager than TC_MAX_QUEUE,so we check
> the return value of netdev_set_num_tc.
>
> Reported-by: syzbot+2b3e5fb6c7ef285a94f6@syzkaller.appspotmail.com
> Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com>
> ---
> net/sched/sch_taprio.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
> index 9c79374..1ab2fc9 100644
> --- a/net/sched/sch_taprio.c
> +++ b/net/sched/sch_taprio.c
> @@ -1513,7 +1513,9 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
> taprio_set_picos_per_byte(dev, q);
>
> if (mqprio) {
> - netdev_set_num_tc(dev, mqprio->num_tc);
> + err = netdev_set_num_tc(dev, mqprio->num_tc);
> + if (err)
> + goto free_sched;
taprio_set_picos_per_byte() already got called and applied some of the
changes. It seems like the early return from taprio_parse_mqprio_opt()
if dev->num_tc is non-zero is incorrect. That function is supposed to
validate that mqprio_opt() is correct AFAIU. That would mean:
Fixes: a3d43c0d56f1 ("taprio: Add support adding an admin schedule")
Vinicius - WDYT?
> for (i = 0; i < mqprio->num_tc; i++)
> netdev_set_tc_queue(dev, i,
> mqprio->count[i],
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH] net:sched fix array-index-out-of-bounds in taprio_change
@ 2021-08-11 4:09 tcs.kernel
0 siblings, 0 replies; 9+ messages in thread
From: tcs.kernel @ 2021-08-11 4:09 UTC (permalink / raw)
To: vinicius.gomes, jhs, xiyou.wangcong, jiri, davem, kuba, netdev
Cc: Haimin Zhang
From: Haimin Zhang <tcs_kernel@tencent.com>
Reported-by: syzbot+2b3e5fb6c7ef285a94f6@syzkaller.appspotmail.com
Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com>
---
net/sched/sch_taprio.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 9c79374..1ab2fc9 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -1513,7 +1513,9 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
taprio_set_picos_per_byte(dev, q);
if (mqprio) {
- netdev_set_num_tc(dev, mqprio->num_tc);
+ err = netdev_set_num_tc(dev, mqprio->num_tc);
+ if (err)
+ goto free_sched;
for (i = 0; i < mqprio->num_tc; i++)
netdev_set_tc_queue(dev, i,
mqprio->count[i],
--
1.8.3.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
end of thread, other threads:[~2021-08-30 16:10 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
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2021-08-11 5:10 [PATCH] net:sched fix array-index-out-of-bounds in taprio_change tcs.kernel
2021-08-11 7:44 ` Eric Dumazet
2021-08-11 8:30 ` Pavel Skripkin
2021-08-11 8:35 ` Pavel Skripkin
2021-08-11 8:36 ` Haimin Zhang
2021-08-30 2:09 ` Haimin Zhang
2021-08-30 16:10 ` Jakub Kicinski
2021-08-12 17:53 ` Jakub Kicinski
-- strict thread matches above, loose matches on Subject: below --
2021-08-11 4:09 tcs.kernel
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