From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: Ilya Maximets <i.maximets@samsung.com>
Cc: dev@dpdk.org, Huawei Xie <huawei.xie@intel.com>,
Rich Lane <rich.lane@bigswitch.com>,
Dyasly Sergey <s.dyasly@samsung.com>,
Heetae Ahn <heetae82.ahn@samsung.com>,
Jianfeng Tan <jianfeng.tan@intel.com>,
Stephen Hemminger <stephen@networkplumber.org>,
Thomas Monjalon <thomas.monjalon@6wind.com>
Subject: Re: [dpdk-dev] [PATCH v2] vhost: fix segfault on bad descriptor address
Date: Fri, 15 Jul 2016 16:40:14 +0800 [thread overview]
Message-ID: <20160715084014.GE5146@yliu-dev.sh.intel.com> (raw)
In-Reply-To: <57888F60.4090206@samsung.com>
On Fri, Jul 15, 2016 at 10:23:12AM +0300, Ilya Maximets wrote:
> On 15.07.2016 09:17, Yuanhan Liu wrote:
> > On Thu, Jul 14, 2016 at 11:18:39AM +0300, Ilya Maximets wrote:
> >> In current implementation vhost will crash with segmentation fault
> >> if malicious or buggy virtio application breaks addresses of descriptors.
> >>
> >> Before commit 0823c1cb0a73 this crash was reproducible even with
> >> normal DPDK application that tries to change number of virtqueues
> >> dynamically inside VM.
> >>
> >> Fix that by checking addresses of descriptors before using.
> >>
> >> Also fixed return value on error for 'copy_mbuf_to_desc_mergeable()'
> >> from '-1' to '0' because it returns unsigned value and it means
> >> number of used descriptors.
> >
> > Yeah, that's a good fix. Thanks.
> >
> > Maybe you'd better make it a standalone patch.
>
> Ok. Maybe I should split this patch in two:
> 1. Fix return value + using of this value (vq->last_used_idx += nr_used;)
> 2. Check addresses of descriptors.
> What do you think?
Good to me.
> >> Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
> >> ---
> >> Version 2:
> >> * Rebased on top of current master.
> >> * host's address now checked in meargeable case,
> >> because needed refactoring already done.
> >> * Commit-message changed because old issue with
> >> virtio reload accidentially fixed by commit
> >> 0823c1cb0a73.
> >>
> >> lib/librte_vhost/vhost_rxtx.c | 28 +++++++++++++++++++++-------
> >> 1 file changed, 21 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
> >> index 15ca956..31e8b58 100644
> >> --- a/lib/librte_vhost/vhost_rxtx.c
> >> +++ b/lib/librte_vhost/vhost_rxtx.c
> >> @@ -147,10 +147,10 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
> >> struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
> >>
> >> desc = &vq->desc[desc_idx];
> >> - if (unlikely(desc->len < dev->vhost_hlen))
> >> + desc_addr = gpa_to_vva(dev, desc->addr);
> >> + if (unlikely(desc->len < dev->vhost_hlen || !desc_addr))
> >> return -1;
> >
> > So, you discards the workaround from Rich?
>
> I can apply it, if you wish. Should I?
Yeah, it's hard to tell. The performace regression is weird after all.
I'm thinking we should appy it anyway: it saves 10% regression, which
is worthwhile. I think we should also add comments there.
--yliu
next prev parent reply other threads:[~2016-07-15 8:37 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-20 12:50 [dpdk-dev] [PATCH] " Ilya Maximets
2016-05-23 10:57 ` Yuanhan Liu
2016-05-23 11:04 ` Ilya Maximets
2016-05-30 11:05 ` Ilya Maximets
2016-05-30 14:25 ` Yuanhan Liu
2016-05-31 9:12 ` Ilya Maximets
2016-05-30 12:00 ` Tan, Jianfeng
2016-05-30 12:24 ` Ilya Maximets
2016-05-31 6:53 ` Tan, Jianfeng
2016-05-31 9:10 ` Ilya Maximets
2016-05-31 22:06 ` Rich Lane
2016-06-02 10:46 ` Ilya Maximets
2016-06-02 16:22 ` Rich Lane
2016-06-03 6:01 ` Ilya Maximets
2016-07-01 7:35 ` Yuanhan Liu
2016-07-06 11:19 ` Ilya Maximets
2016-07-06 12:24 ` Yuanhan Liu
2016-07-08 11:48 ` Ilya Maximets
2016-07-10 13:17 ` Yuanhan Liu
2016-07-11 8:38 ` Yuanhan Liu
2016-07-11 9:50 ` Ilya Maximets
2016-07-11 11:05 ` Yuanhan Liu
2016-07-11 11:47 ` Ilya Maximets
2016-07-12 2:43 ` Yuanhan Liu
2016-07-12 5:53 ` Ilya Maximets
2016-07-13 7:34 ` Ilya Maximets
2016-07-13 8:47 ` Yuanhan Liu
2016-07-13 15:54 ` Rich Lane
2016-07-14 1:42 ` Yuanhan Liu
2016-07-14 4:38 ` Ilya Maximets
2016-07-14 8:18 ` [dpdk-dev] [PATCH v2] " Ilya Maximets
2016-07-15 6:17 ` Yuanhan Liu
2016-07-15 7:23 ` Ilya Maximets
2016-07-15 8:40 ` Yuanhan Liu [this message]
2016-07-15 11:15 ` [dpdk-dev] [PATCH v3 0/2] " Ilya Maximets
2016-07-15 11:15 ` [dpdk-dev] [PATCH v3 1/2] vhost: fix using of bad return value on mergeable enqueue Ilya Maximets
2016-07-15 11:15 ` [dpdk-dev] [PATCH v3 2/2] vhost: do sanity check for ring descriptor address Ilya Maximets
2016-07-15 12:14 ` [dpdk-dev] [PATCH v3 0/2] vhost: fix segfault on bad " Yuanhan Liu
2016-07-15 19:37 ` Thomas Monjalon
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