Messages in this thread | | | Subject | Re: [PATCH] virtio_net: Remove BUG() to aviod machine dead | From | Jason Wang <> | Date | Wed, 2 Jun 2021 15:14:50 +0800 |
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在 2021/6/2 下午1:59, Leon Romanovsky 写道: > On Tue, May 25, 2021 at 02:19:03PM +0800, Jason Wang wrote: >> 在 2021/5/19 下午10:18, Xianting Tian 写道: >>> thanks, I submit the patch as commented by Andrew >>> https://lkml.org/lkml/2021/5/18/256 >>> >>> Actually, if xmit_skb() returns error, below code will give a warning >>> with error code. >>> >>> /* Try to transmit */ >>> err = xmit_skb(sq, skb); >>> >>> /* This should not happen! */ >>> if (unlikely(err)) { >>> dev->stats.tx_fifo_errors++; >>> if (net_ratelimit()) >>> dev_warn(&dev->dev, >>> "Unexpected TXQ (%d) queue failure: %d\n", >>> qnum, err); >>> dev->stats.tx_dropped++; >>> dev_kfree_skb_any(skb); >>> return NETDEV_TX_OK; >>> } >>> >>> >>> >>> >>> >>> 在 2021/5/18 下午5:54, Michael S. Tsirkin 写道: >>>> typo in subject >>>> >>>> On Tue, May 18, 2021 at 05:46:56PM +0800, Xianting Tian wrote: >>>>> When met error, we output a print to avoid a BUG(). >> >> So you don't explain why you need to remove BUG(). I think it deserve a >> BUG(). > BUG() will crash the machine and virtio_net is not kernel core > functionality that must stop the machine to prevent anything truly > harmful and basic.
Note that the BUG() here is not for virtio-net itself. It tells us that a bug was found by virtio-net.
That is, the one that produces the skb has a bug, usually it's the network core.
There could also be the issue of the packet from untrusted source (userspace like TAP or packet socket) but they should be validated there.
Thanks
> > I would argue that code in drivers/* shouldn't call BUG() macros at all. > > If it is impossible, don't check for that or add WARN_ON() and recover, > but don't crash whole system. > > Thanks >
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