From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: David Hunt <david.hunt@intel.com>, dev@dpdk.org
Cc: stable@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v2] examples/vm_power_manager: fix string null termination
Date: Fri, 26 Apr 2019 12:56:08 +0100 [thread overview]
Message-ID: <339cb6ac-9c56-b9cb-28e8-950ad2cd70b4@intel.com> (raw)
Message-ID: <20190426115608.JP_M3bTq4nzqXzbcicIP8GU02zzWzkD5-bSfXdLtxbg@z> (raw)
In-Reply-To: <20190426112422.15719-1-david.hunt@intel.com>
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
next prev parent reply other threads:[~2019-04-26 11:56 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-26 8:43 [dpdk-dev] [PATCH v1] " David Hunt
2019-04-26 8:43 ` David Hunt
2019-04-26 10:33 ` Burakov, Anatoly
2019-04-26 10:33 ` Burakov, Anatoly
2019-04-26 11:16 ` Hunt, David
2019-04-26 11:16 ` Hunt, David
2019-04-26 11:24 ` [dpdk-dev] [PATCH v2] " David Hunt
2019-04-26 11:24 ` David Hunt
2019-04-26 11:56 ` Burakov, Anatoly [this message]
2019-04-26 11:56 ` Burakov, Anatoly
2019-04-26 12:31 ` Bruce Richardson
2019-04-26 12:31 ` Bruce Richardson
2019-04-26 12:47 ` Burakov, Anatoly
2019-04-26 12:47 ` Burakov, Anatoly
2019-04-26 14:04 ` [dpdk-dev] [PATCH v3] " David Hunt
2019-04-26 14:04 ` David Hunt
2019-04-26 14:10 ` Burakov, Anatoly
2019-04-26 14:10 ` Burakov, Anatoly
2019-05-02 23:43 ` Thomas Monjalon
2019-05-02 23:43 ` Thomas Monjalon
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