From: zhong jiang <zhongjiang@huawei•com>
To: Gao Feng <fgao@ikuai8•com>
Cc: "David S. Miller" <davem@davemloft•net>,
Alex Duyck <aduyck@mirantis•com>,
Tom Herbert <tom@herbertland•com>, <jiri@mellanox•com>,
<hadarh@mellanox•com>, <amir@vadai•me>,
Linux Kernel Network Developers <netdev@vger•kernel.org>,
linux-kernel <linux-kernel@vger•kernel.org>
Subject: Re: [PATCH] net: avoid uninitialized variable
Date: Thu, 27 Oct 2016 13:53:30 +0800 [thread overview]
Message-ID: <5811965A.7060301@huawei.com> (raw)
In-Reply-To: <CA+6hz4rniDvOBL65k_c2SqN+nTCrdUBLkHoo6XdtqfZUPgRVeQ@mail.gmail.com>
On 2016/10/27 12:02, Gao Feng wrote:
> On Thu, Oct 27, 2016 at 11:56 AM, zhongjiang <zhongjiang@huawei•com> wrote:
>> From: zhong jiang <zhongjiang@huawei•com>
>>
>> when I compiler the newest kernel, I hit the following error with
>> Werror=may-uninitalized.
>>
>> net/core/flow_dissector.c: In function ?._skb_flow_dissect?
>> include/uapi/linux/swab.h:100:46: error: ?.lan?.may be used uninitialized in this function [-Werror=maybe-uninitialized]
>> net/core/flow_dissector.c:248:26: note: ?.lan?.was declared here
>>
>> This adds an additional check for proto to explicitly tell the compiler
>> that vlan pointer have the correct value before it is used.
>>
>> Signed-off-by: zhong jiang <zhongjiang@huawei•com>
>> ---
>> net/core/flow_dissector.c | 5 +++--
>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
>> index 1a7b80f..a04d9cf 100644
>> --- a/net/core/flow_dissector.c
>> +++ b/net/core/flow_dissector.c
>> @@ -245,7 +245,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
>> }
>> case htons(ETH_P_8021AD):
>> case htons(ETH_P_8021Q): {
>> - const struct vlan_hdr *vlan;
>> + const struct vlan_hdr *vlan = NULL;
>>
>> if (skb_vlan_tag_present(skb))
>> proto = skb->protocol;
>> @@ -276,7 +276,8 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
>> key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
>> key_vlan->vlan_priority =
>> (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
>> - } else {
>> + } else if (proto == cpu_to_be16(ETH_P_8021Q) ||
>> + proto == cpu_to_be16(ETH_P_8021AD)) {
>> key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
>> VLAN_VID_MASK;
>> key_vlan->vlan_priority =
>> --
>> 1.8.3.1
>>
> It seems there is one similar patch already.
> You could refer to https://patchwork.kernel.org/patch/9389565/
>
> Regards
> Feng
>
> .
>
sorry, I doesn't notice that patch.
Thanks
zhongjiang
prev parent reply other threads:[~2016-10-27 5:53 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-27 3:56 [PATCH] net: avoid uninitialized variable zhongjiang
2016-10-27 4:02 ` Gao Feng
2016-10-27 5:53 ` zhong jiang [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5811965A.7060301@huawei.com \
--to=zhongjiang@huawei$(echo .)com \
--cc=aduyck@mirantis$(echo .)com \
--cc=amir@vadai$(echo .)me \
--cc=davem@davemloft$(echo .)net \
--cc=fgao@ikuai8$(echo .)com \
--cc=hadarh@mellanox$(echo .)com \
--cc=jiri@mellanox$(echo .)com \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=netdev@vger$(echo .)kernel.org \
--cc=tom@herbertland$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox