From: Yanjun Zhu <yanjun.zhu@oracle.com>
To: Jia-Ju Bai <baijiaju1990@gmail.com>,
davem@davemloft.net, keescook@chromium.org
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: nvidia: forcedeth: Fix two possible concurrency use-after-free bugs
Date: Wed, 9 Jan 2019 09:24:48 +0800 [thread overview]
Message-ID: <f87bd4b7-81d5-1f0c-137e-ecbc02753257@oracle.com> (raw)
In-Reply-To: <f9ab7ba3-573c-6703-1b01-37a9e0a9b769@gmail.com>
On 2019/1/8 20:57, Jia-Ju Bai wrote:
>
>
> On 2019/1/8 20:54, Zhu Yanjun wrote:
>>
>> 在 2019/1/8 20:45, Jia-Ju Bai 写道:
>>> In drivers/net/ethernet/nvidia/forcedeth.c, the functions
>>> nv_start_xmit() and nv_start_xmit_optimized() can be concurrently
>>> executed with nv_poll_controller().
>>>
>>> nv_start_xmit
>>> line 2321: prev_tx_ctx->skb = skb;
>>>
>>> nv_start_xmit_optimized
>>> line 2479: prev_tx_ctx->skb = skb;
>>>
>>> nv_poll_controller
>>> nv_do_nic_poll
>>> line 4134: spin_lock(&np->lock);
>>> nv_drain_rxtx
>>> nv_drain_tx
>>> nv_release_txskb
>>> line 2004: dev_kfree_skb_any(tx_skb->skb);
>>>
>>> Thus, two possible concurrency use-after-free bugs may occur.
>>>
>>> To fix these possible bugs,
>>
>>
>> Does this really occur? Can you reproduce this ?
>
> This bug is not found by the real execution.
> It is found by a static tool written by myself, and then I check it by
> manual code review.
Before "line 2004: dev_kfree_skb_any(tx_skb->skb); ",
"
nv_disable_irq(dev);
nv_napi_disable(dev);
netif_tx_lock_bh(dev);
netif_addr_lock(dev);
spin_lock(&np->lock);
/* stop engines */
nv_stop_rxtx(dev); <---this stop rxtx
nv_txrx_reset(dev);
"
In this case, does nv_start_xmit or nv_start_xmit_optimized still work well?
Zhu Yanjun
>
>
> Best wishes,
> Jia-Ju Bai
next prev parent reply other threads:[~2019-01-09 1:25 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-08 12:45 [PATCH] net: nvidia: forcedeth: Fix two possible concurrency use-after-free bugs Jia-Ju Bai
2019-01-08 12:54 ` Zhu Yanjun
2019-01-08 12:57 ` Jia-Ju Bai
2019-01-09 1:24 ` Yanjun Zhu [this message]
2019-01-09 2:03 ` Jia-Ju Bai
2019-01-09 2:35 ` Yanjun Zhu
2019-01-09 3:20 ` Jia-Ju Bai
2019-01-09 3:24 ` Yanjun Zhu
2019-01-09 3:25 ` Jia-Ju Bai
2019-01-12 1:53 ` David Miller
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