From: David Miller <davem@davemloft.net>
To: linyunsheng@huawei.com
Cc: tanhuazhong@huawei.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, salil.mehta@huawei.com,
yisen.zhuang@huawei.com, linuxarm@huawei.com,
jakub.kicinski@netronome.com
Subject: Re: [PATCH net 2/3] net: hns3: fix a use after free problem in hns3_nic_maybe_stop_tx()
Date: Tue, 03 Dec 2019 11:57:41 -0800 (PST) [thread overview]
Message-ID: <20191203.115741.976811473066862969.davem@davemloft.net> (raw)
In-Reply-To: <138d0858-7240-ff75-a38c-55e10eefc28d@huawei.com>
From: Yunsheng Lin <linyunsheng@huawei.com>
Date: Tue, 3 Dec 2019 12:22:11 +0800
> 2. When skb_copy() returns success, the hns3_nic_maybe_stop_tx()
> returns -EBUSY when there are not no enough space in the ring to
> send the skb to hardware, and hns3_nic_net_xmit() will return
> NETDEV_TX_BUSY to the upper layer, the upper layer will resend the old
> skb later when driver wakes up the queue, but the old skb has been freed
> by the hns3_nic_maybe_stop_tx(). Because when using the skb_copy() to
> linearize a skb, it will return a new linearized skb, and the old skb is
> freed, the upper layer does not have a reference to the new skb and resend
> using the old skb, which casues a use after freed problem.
>
> This patch is trying to fixes the case 2.
>
> Maybe I should mention why hns3_nic_maybe_stop_tx() returns -EBUSY to
> better describe the problem?
I think it would help understand the code path you are fixing, yes.
next prev parent reply other threads:[~2019-12-03 19:57 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-03 3:08 [PATCH net 0/3] net: hns3: fixes for -net Huazhong Tan
2019-12-03 3:08 ` [PATCH net 1/3] net: hns3: fix for TX queue not restarted problem Huazhong Tan
2019-12-03 3:25 ` David Miller
2019-12-03 4:28 ` Yunsheng Lin
2019-12-03 8:48 ` David Miller
2019-12-04 1:32 ` Yunsheng Lin
2019-12-03 3:08 ` [PATCH net 2/3] net: hns3: fix a use after free problem in hns3_nic_maybe_stop_tx() Huazhong Tan
2019-12-03 3:28 ` David Miller
2019-12-03 4:22 ` Yunsheng Lin
2019-12-03 19:57 ` David Miller [this message]
2019-12-04 1:33 ` Yunsheng Lin
2019-12-03 3:08 ` [PATCH net 3/3] net: hns3: fix VF ID issue for setting VF VLAN Huazhong Tan
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