* [dpdk-stable] [PATCH v1] examples/vm_power_manager: fix string null termination
@ 2019-04-26 8:43 David Hunt
2019-04-26 10:33 ` [dpdk-stable] [dpdk-dev] " Burakov, Anatoly
2019-04-26 11:24 ` [dpdk-stable] [PATCH v2] " David Hunt
0 siblings, 2 replies; 10+ messages in thread
From: David Hunt @ 2019-04-26 8:43 UTC (permalink / raw)
To: dev; +Cc: david.hunt, stable
coverity complains about a null-termination after a read,
so we terminate conditionally on whether idx is within
the buffer or at the end of the buffer.
Coverity issue: 337680
Fixes: a63504a90f ("examples/power: add JSON string handling")
CC: stable@dpdk.org
Signed-off-by: David Hunt <david.hunt@intel.com>
---
examples/vm_power_manager/channel_monitor.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/examples/vm_power_manager/channel_monitor.c b/examples/vm_power_manager/channel_monitor.c
index 971e4f2bc..711722fef 100644
--- a/examples/vm_power_manager/channel_monitor.c
+++ b/examples/vm_power_manager/channel_monitor.c
@@ -808,6 +808,7 @@ read_json_packet(struct channel_info *chan_info)
int indent = 0;
do {
n_bytes = read(chan_info->fd, &json_data[idx], 1);
+ json_data[idx + (idx < MAX_JSON_STRING_LEN - 1)] = '\0';
if (n_bytes == 0)
break;
if (json_data[idx] == '{')
--
2.17.1
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [dpdk-stable] [dpdk-dev] [PATCH v1] examples/vm_power_manager: fix string null termination
2019-04-26 8:43 [dpdk-stable] [PATCH v1] examples/vm_power_manager: fix string null termination David Hunt
@ 2019-04-26 10:33 ` Burakov, Anatoly
2019-04-26 11:16 ` Hunt, David
2019-04-26 11:24 ` [dpdk-stable] [PATCH v2] " David Hunt
1 sibling, 1 reply; 10+ messages in thread
From: Burakov, Anatoly @ 2019-04-26 10:33 UTC (permalink / raw)
To: David Hunt, dev; +Cc: stable
On 26-Apr-19 9:43 AM, David Hunt wrote:
> coverity complains about a null-termination after a read,
> so we terminate conditionally on whether idx is within
> the buffer or at the end of the buffer.
>
> Coverity issue: 337680
> Fixes: a63504a90f ("examples/power: add JSON string handling")
> CC: stable@dpdk.org
> Signed-off-by: David Hunt <david.hunt@intel.com>
> ---
> examples/vm_power_manager/channel_monitor.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/examples/vm_power_manager/channel_monitor.c b/examples/vm_power_manager/channel_monitor.c
> index 971e4f2bc..711722fef 100644
> --- a/examples/vm_power_manager/channel_monitor.c
> +++ b/examples/vm_power_manager/channel_monitor.c
> @@ -808,6 +808,7 @@ read_json_packet(struct channel_info *chan_info)
> int indent = 0;
> do {
> n_bytes = read(chan_info->fd, &json_data[idx], 1);
> + json_data[idx + (idx < MAX_JSON_STRING_LEN - 1)] = '\0';
Why do it inside the loop and not after?
> if (n_bytes == 0)
> break;
> if (json_data[idx] == '{')
>
--
Thanks,
Anatoly
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [dpdk-stable] [dpdk-dev] [PATCH v1] examples/vm_power_manager: fix string null termination
2019-04-26 10:33 ` [dpdk-stable] [dpdk-dev] " Burakov, Anatoly
@ 2019-04-26 11:16 ` Hunt, David
0 siblings, 0 replies; 10+ messages in thread
From: Hunt, David @ 2019-04-26 11:16 UTC (permalink / raw)
To: Burakov, Anatoly, dev; +Cc: stable
Hi Anatoly,
On 26/4/2019 11:33 AM, Burakov, Anatoly wrote:
> On 26-Apr-19 9:43 AM, David Hunt wrote:
>> coverity complains about a null-termination after a read,
>> so we terminate conditionally on whether idx is within
>> the buffer or at the end of the buffer.
>>
>> Coverity issue: 337680
>> Fixes: a63504a90f ("examples/power: add JSON string handling")
>> CC: stable@dpdk.org
>> Signed-off-by: David Hunt <david.hunt@intel.com>
>> ---
>> examples/vm_power_manager/channel_monitor.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/examples/vm_power_manager/channel_monitor.c
>> b/examples/vm_power_manager/channel_monitor.c
>> index 971e4f2bc..711722fef 100644
>> --- a/examples/vm_power_manager/channel_monitor.c
>> +++ b/examples/vm_power_manager/channel_monitor.c
>> @@ -808,6 +808,7 @@ read_json_packet(struct channel_info *chan_info)
>> int indent = 0;
>> do {
>> n_bytes = read(chan_info->fd, &json_data[idx], 1);
>> + json_data[idx + (idx < MAX_JSON_STRING_LEN - 1)] = '\0';
>
> Why do it inside the loop and not after?
>
No reason, really. I'll move it outside and re-spin.
>> if (n_bytes == 0)
>> break;
>> if (json_data[idx] == '{')
>>
>
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* [dpdk-stable] [PATCH v2] examples/vm_power_manager: fix string null termination
2019-04-26 8:43 [dpdk-stable] [PATCH v1] examples/vm_power_manager: fix string null termination David Hunt
2019-04-26 10:33 ` [dpdk-stable] [dpdk-dev] " Burakov, Anatoly
@ 2019-04-26 11:24 ` David Hunt
2019-04-26 11:56 ` [dpdk-stable] [dpdk-dev] " Burakov, Anatoly
2019-04-26 14:04 ` [dpdk-stable] [PATCH v3] " David Hunt
1 sibling, 2 replies; 10+ messages in thread
From: David Hunt @ 2019-04-26 11:24 UTC (permalink / raw)
To: dev; +Cc: david.hunt, stable
coverity complains about a null-termination after a read,
so we terminate after exiting the do-while loop. The position
is conditional on whether idx is within the buffer or at the
end of the buffer.
Coverity issue: 337680
Fixes: a63504a90f ("examples/power: add JSON string handling")
CC: stable@dpdk.org
Signed-off-by: David Hunt <david.hunt@intel.com>
---
v2:
* Move null termination outside of do-while.
---
examples/vm_power_manager/channel_monitor.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/examples/vm_power_manager/channel_monitor.c b/examples/vm_power_manager/channel_monitor.c
index 971e4f2bc..03fdcd15a 100644
--- a/examples/vm_power_manager/channel_monitor.c
+++ b/examples/vm_power_manager/channel_monitor.c
@@ -822,6 +822,8 @@ read_json_packet(struct channel_info *chan_info)
break;
} while (indent > 0);
+ json_data[idx + (idx < MAX_JSON_STRING_LEN - 1)] = '\0';
+
if (indent > 0)
/*
* We've broken out of the read loop without getting
--
2.17.1
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [dpdk-stable] [dpdk-dev] [PATCH v2] examples/vm_power_manager: fix string null termination
2019-04-26 11:24 ` [dpdk-stable] [PATCH v2] " David Hunt
@ 2019-04-26 11:56 ` Burakov, Anatoly
2019-04-26 12:31 ` Bruce Richardson
2019-04-26 14:04 ` [dpdk-stable] [PATCH v3] " David Hunt
1 sibling, 1 reply; 10+ messages in thread
From: Burakov, Anatoly @ 2019-04-26 11:56 UTC (permalink / raw)
To: David Hunt, dev; +Cc: stable
On 26-Apr-19 12:24 PM, David Hunt wrote:
> coverity complains about a null-termination after a read,
> so we terminate after exiting the do-while loop. The position
> is conditional on whether idx is within the buffer or at the
> end of the buffer.
>
> Coverity issue: 337680
> Fixes: a63504a90f ("examples/power: add JSON string handling")
> CC: stable@dpdk.org
>
> Signed-off-by: David Hunt <david.hunt@intel.com>
>
> ---
> v2:
> * Move null termination outside of do-while.
> ---
> examples/vm_power_manager/channel_monitor.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/examples/vm_power_manager/channel_monitor.c b/examples/vm_power_manager/channel_monitor.c
> index 971e4f2bc..03fdcd15a 100644
> --- a/examples/vm_power_manager/channel_monitor.c
> +++ b/examples/vm_power_manager/channel_monitor.c
> @@ -822,6 +822,8 @@ read_json_packet(struct channel_info *chan_info)
> break;
> } while (indent > 0);
>
> + json_data[idx + (idx < MAX_JSON_STRING_LEN - 1)] = '\0';
> +
I don't think you need this complicated logic here. You start at idx =
0, so even if you receive 0 bytes, you'll terminate buffer at index 0.
You also break when idx reaches (MAX_JSON_STRING_LEN - 1), so it's also
safe to do json_data[idx] after the loop. In all other cases, you still
increment idx before breaking out (e.g. when reaching indent == 0), so
it's also safe to do json_data[idx] in those cases.
> if (indent > 0)
> /*
> * We've broken out of the read loop without getting
>
--
Thanks,
Anatoly
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [dpdk-stable] [dpdk-dev] [PATCH v2] examples/vm_power_manager: fix string null termination
2019-04-26 11:56 ` [dpdk-stable] [dpdk-dev] " Burakov, Anatoly
@ 2019-04-26 12:31 ` Bruce Richardson
2019-04-26 12:47 ` Burakov, Anatoly
0 siblings, 1 reply; 10+ messages in thread
From: Bruce Richardson @ 2019-04-26 12:31 UTC (permalink / raw)
To: Burakov, Anatoly; +Cc: David Hunt, dev, stable
On Fri, Apr 26, 2019 at 12:56:08PM +0100, Burakov, Anatoly wrote:
> On 26-Apr-19 12:24 PM, David Hunt wrote:
> > coverity complains about a null-termination after a read,
> > so we terminate after exiting the do-while loop. The position
> > is conditional on whether idx is within the buffer or at the
> > end of the buffer.
> >
> > Coverity issue: 337680
> > Fixes: a63504a90f ("examples/power: add JSON string handling")
> > CC: stable@dpdk.org
> >
> > Signed-off-by: David Hunt <david.hunt@intel.com>
> >
> > ---
> > v2:
> > * Move null termination outside of do-while.
> > ---
> > examples/vm_power_manager/channel_monitor.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/examples/vm_power_manager/channel_monitor.c b/examples/vm_power_manager/channel_monitor.c
> > index 971e4f2bc..03fdcd15a 100644
> > --- a/examples/vm_power_manager/channel_monitor.c
> > +++ b/examples/vm_power_manager/channel_monitor.c
> > @@ -822,6 +822,8 @@ read_json_packet(struct channel_info *chan_info)
> > break;
> > } while (indent > 0);
> > + json_data[idx + (idx < MAX_JSON_STRING_LEN - 1)] = '\0';
> > +
>
> I don't think you need this complicated logic here. You start at idx = 0, so
> even if you receive 0 bytes, you'll terminate buffer at index 0. You also
> break when idx reaches (MAX_JSON_STRING_LEN - 1), so it's also safe to do
> json_data[idx] after the loop. In all other cases, you still increment idx
> before breaking out (e.g. when reaching indent == 0), so it's also safe to
> do json_data[idx] in those cases.
>
+1 to that.
An alternative and simpler option might be to memset the who array to zero
before you start anyway.
/Bruce
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [dpdk-stable] [dpdk-dev] [PATCH v2] examples/vm_power_manager: fix string null termination
2019-04-26 12:31 ` Bruce Richardson
@ 2019-04-26 12:47 ` Burakov, Anatoly
0 siblings, 0 replies; 10+ messages in thread
From: Burakov, Anatoly @ 2019-04-26 12:47 UTC (permalink / raw)
To: Bruce Richardson; +Cc: David Hunt, dev, stable
On 26-Apr-19 1:31 PM, Bruce Richardson wrote:
> On Fri, Apr 26, 2019 at 12:56:08PM +0100, Burakov, Anatoly wrote:
>> On 26-Apr-19 12:24 PM, David Hunt wrote:
>>> coverity complains about a null-termination after a read,
>>> so we terminate after exiting the do-while loop. The position
>>> is conditional on whether idx is within the buffer or at the
>>> end of the buffer.
>>>
>>> Coverity issue: 337680
>>> Fixes: a63504a90f ("examples/power: add JSON string handling")
>>> CC: stable@dpdk.org
>>>
>>> Signed-off-by: David Hunt <david.hunt@intel.com>
>>>
>>> ---
>>> v2:
>>> * Move null termination outside of do-while.
>>> ---
>>> examples/vm_power_manager/channel_monitor.c | 2 ++
>>> 1 file changed, 2 insertions(+)
>>>
>>> diff --git a/examples/vm_power_manager/channel_monitor.c b/examples/vm_power_manager/channel_monitor.c
>>> index 971e4f2bc..03fdcd15a 100644
>>> --- a/examples/vm_power_manager/channel_monitor.c
>>> +++ b/examples/vm_power_manager/channel_monitor.c
>>> @@ -822,6 +822,8 @@ read_json_packet(struct channel_info *chan_info)
>>> break;
>>> } while (indent > 0);
>>> + json_data[idx + (idx < MAX_JSON_STRING_LEN - 1)] = '\0';
>>> +
>>
>> I don't think you need this complicated logic here. You start at idx = 0, so
>> even if you receive 0 bytes, you'll terminate buffer at index 0. You also
>> break when idx reaches (MAX_JSON_STRING_LEN - 1), so it's also safe to do
>> json_data[idx] after the loop. In all other cases, you still increment idx
>> before breaking out (e.g. when reaching indent == 0), so it's also safe to
>> do json_data[idx] in those cases.
>>
> +1 to that.
>
> An alternative and simpler option might be to memset the who array to zero
> before you start anyway.
That'll cost us few extra cycles on a non-performance critical path full
of syscalls, surely we can't have that! :)
>
> /Bruce
>
--
Thanks,
Anatoly
^ permalink raw reply [flat|nested] 10+ messages in thread
* [dpdk-stable] [PATCH v3] examples/vm_power_manager: fix string null termination
2019-04-26 11:24 ` [dpdk-stable] [PATCH v2] " David Hunt
2019-04-26 11:56 ` [dpdk-stable] [dpdk-dev] " Burakov, Anatoly
@ 2019-04-26 14:04 ` David Hunt
2019-04-26 14:10 ` [dpdk-stable] [dpdk-dev] " Burakov, Anatoly
1 sibling, 1 reply; 10+ messages in thread
From: David Hunt @ 2019-04-26 14:04 UTC (permalink / raw)
To: dev; +Cc: david.hunt, stable
coverity complains about a null-termination after a read,
so we terminate once we exit the do-while read loop.
Coverity issue: 337680
Fixes: a63504a90f ("examples/power: add JSON string handling")
CC: stable@dpdk.org
Signed-off-by: David Hunt <david.hunt@intel.com>
---
v2: Move null termination outside of do-while.
v3: Simplify null termimation
---
examples/vm_power_manager/channel_monitor.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/examples/vm_power_manager/channel_monitor.c b/examples/vm_power_manager/channel_monitor.c
index 971e4f2bc..4a287109b 100644
--- a/examples/vm_power_manager/channel_monitor.c
+++ b/examples/vm_power_manager/channel_monitor.c
@@ -822,12 +822,7 @@ read_json_packet(struct channel_info *chan_info)
break;
} while (indent > 0);
- if (indent > 0)
- /*
- * We've broken out of the read loop without getting
- * a closing brace, so throw away the data
- */
- json_data[idx] = 0;
+ json_data[idx] = '\0';
if (strlen(json_data) == 0)
continue;
--
2.17.1
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [dpdk-stable] [dpdk-dev] [PATCH v3] examples/vm_power_manager: fix string null termination
2019-04-26 14:04 ` [dpdk-stable] [PATCH v3] " David Hunt
@ 2019-04-26 14:10 ` Burakov, Anatoly
2019-05-02 23:43 ` Thomas Monjalon
0 siblings, 1 reply; 10+ messages in thread
From: Burakov, Anatoly @ 2019-04-26 14:10 UTC (permalink / raw)
To: David Hunt, dev; +Cc: stable
On 26-Apr-19 3:04 PM, David Hunt wrote:
> coverity complains about a null-termination after a read,
> so we terminate once we exit the do-while read loop.
>
> Coverity issue: 337680
> Fixes: a63504a90f ("examples/power: add JSON string handling")
> CC: stable@dpdk.org
>
> Signed-off-by: David Hunt <david.hunt@intel.com>
>
> ---
> v2: Move null termination outside of do-while.
> v3: Simplify null termimation
> ---
> examples/vm_power_manager/channel_monitor.c | 7 +------
> 1 file changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/examples/vm_power_manager/channel_monitor.c b/examples/vm_power_manager/channel_monitor.c
> index 971e4f2bc..4a287109b 100644
> --- a/examples/vm_power_manager/channel_monitor.c
> +++ b/examples/vm_power_manager/channel_monitor.c
> @@ -822,12 +822,7 @@ read_json_packet(struct channel_info *chan_info)
> break;
> } while (indent > 0);
>
> - if (indent > 0)
> - /*
> - * We've broken out of the read loop without getting
> - * a closing brace, so throw away the data
> - */
> - json_data[idx] = 0;
> + json_data[idx] = '\0';
>
> if (strlen(json_data) == 0)
> continue;
>
Reviewed-by: Anatoly Burakov <anatoly.burakov@intel.com>
--
Thanks,
Anatoly
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [dpdk-stable] [dpdk-dev] [PATCH v3] examples/vm_power_manager: fix string null termination
2019-04-26 14:10 ` [dpdk-stable] [dpdk-dev] " Burakov, Anatoly
@ 2019-05-02 23:43 ` Thomas Monjalon
0 siblings, 0 replies; 10+ messages in thread
From: Thomas Monjalon @ 2019-05-02 23:43 UTC (permalink / raw)
To: David Hunt; +Cc: dev, Burakov, Anatoly, stable
26/04/2019 16:10, Burakov, Anatoly:
> On 26-Apr-19 3:04 PM, David Hunt wrote:
> > coverity complains about a null-termination after a read,
> > so we terminate once we exit the do-while read loop.
> >
> > Coverity issue: 337680
> > Fixes: a63504a90f ("examples/power: add JSON string handling")
> > CC: stable@dpdk.org
> >
> > Signed-off-by: David Hunt <david.hunt@intel.com>
>
> Reviewed-by: Anatoly Burakov <anatoly.burakov@intel.com>
Applied, thanks
PS: replaced "string" with "json" in title to give a bit more context.
^ permalink raw reply [flat|nested] 10+ messages in thread
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2019-04-26 8:43 [dpdk-stable] [PATCH v1] examples/vm_power_manager: fix string null termination David Hunt
2019-04-26 10:33 ` [dpdk-stable] [dpdk-dev] " Burakov, Anatoly
2019-04-26 11:16 ` Hunt, David
2019-04-26 11:24 ` [dpdk-stable] [PATCH v2] " David Hunt
2019-04-26 11:56 ` [dpdk-stable] [dpdk-dev] " Burakov, Anatoly
2019-04-26 12:31 ` Bruce Richardson
2019-04-26 12:47 ` Burakov, Anatoly
2019-04-26 14:04 ` [dpdk-stable] [PATCH v3] " David Hunt
2019-04-26 14:10 ` [dpdk-stable] [dpdk-dev] " Burakov, Anatoly
2019-05-02 23:43 ` Thomas Monjalon
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