From: David Palma <david.palma@ntnu.no>
To: Stefan Schmidt <stefan@datenfreihafen.org>,
Alexander Aring <aring@mojatatu.com>,
stefan@osg.samsung.com
Cc: linux-wpan@vger.kernel.org, netdev@vger.kernel.org,
kernel@mojatatu.com,
Rabi Narayan Sahoo <rabinarayans0828@gmail.com>
Subject: Re: [PATCH wpan 1/2] net: 6lowpan: fix reserved space for single frames
Date: Fri, 6 Jul 2018 09:54:51 +0200 [thread overview]
Message-ID: <781a24ed-3783-abbf-7726-f377fd5eabca@ntnu.no> (raw)
In-Reply-To: <a2cb217f-7e22-e603-bd46-13d8764fee64@datenfreihafen.org>
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Hi Stefan,
On 05/07/18 13:16, Stefan Schmidt wrote:
> Hello.
>
> [CC David Palma and Rabi Narayan Sahoo]
>
> On 02.07.2018 22:32, Alexander Aring wrote:
>> This patch fixes patch add handling to take care tail and headroom for
>> single 6lowpan frames. We need to be sure we have a skb with the right
>> head and tailroom for single frames. This patch do it by using
>> skb_copy_expand() if head and tailroom is not enough allocated by upper
>> layer.
>>
>> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=195059
>> Reported-by: David Palma <david.palma@ntnu.no>
>> Reported-by: Rabi Narayan Sahoo <rabinarayans0828@gmail.com>
>> Signed-off-by: Alexander Aring <aring@mojatatu.com>
>
> David, Rabi and you please test these two patches and verify that it
> fixes the problems you have?
>
> regards
> Stefan Schmidt
>
The patches fix the problems!
I've tested them against different packet sizes and no kernel panic.
The patches were applied in Debian's 4.9.88-1+deb9u1 x86_64 kernel,
which before the patches showed the reported issue.
Thanks again to Alex for looking into it.
Cheers,
--
David
>> ---
>> net/ieee802154/6lowpan/tx.c | 21 ++++++++++++++++++---
>> 1 file changed, 18 insertions(+), 3 deletions(-)
>>
>> diff --git a/net/ieee802154/6lowpan/tx.c b/net/ieee802154/6lowpan/tx.c
>> index e6ff5128e61a..d0c4d220de08 100644
>> --- a/net/ieee802154/6lowpan/tx.c
>> +++ b/net/ieee802154/6lowpan/tx.c
>> @@ -265,9 +265,24 @@ netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev)
>> /* We must take a copy of the skb before we modify/replace the ipv6
>> * header as the header could be used elsewhere
>> */
>> - skb = skb_unshare(skb, GFP_ATOMIC);
>> - if (!skb)
>> - return NET_XMIT_DROP;
>> + if (unlikely(skb_headroom(skb) < ldev->needed_headroom ||
>> + skb_tailroom(skb) < ldev->needed_tailroom)) {
>> + struct sk_buff *nskb;
>> +
>> + nskb = skb_copy_expand(skb, ldev->needed_headroom,
>> + ldev->needed_tailroom, GFP_ATOMIC);
>> + if (likely(skb)) {
>> + consume_skb(skb);
>> + skb = nskb;
>> + } else {
>> + kfree_skb(skb);
>> + return NET_XMIT_DROP;
>> + }
>> + } else {
>> + skb = skb_unshare(skb, GFP_ATOMIC);
>> + if (!skb)
>> + return NET_XMIT_DROP;
>> + }
>>
>> ret = lowpan_header(skb, ldev, &dgram_size, &dgram_offset);
>> if (ret < 0) {
>>
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next prev parent reply other threads:[~2018-07-06 7:55 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-02 20:32 [PATCH wpan 1/2] net: 6lowpan: fix reserved space for single frames Alexander Aring
2018-07-02 20:32 ` [PATCH wpan 2/2] net: mac802154: tx: expand tailroom if necessary Alexander Aring
2018-08-06 9:26 ` Stefan Schmidt
2018-07-05 11:16 ` [PATCH wpan 1/2] net: 6lowpan: fix reserved space for single frames Stefan Schmidt
2018-07-06 7:54 ` David Palma [this message]
2018-07-06 8:07 ` Stefan Schmidt
2018-07-06 10:06 ` Stefan Schmidt
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