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From: David Ahern <dsahern@gmail.com>
To: Xin Long <lucien.xin@gmail.com>,
	syzbot <syzbot+03bee3680a37466775e7@syzkaller.appspotmail.com>
Cc: Jason@zx2c4.com, "Andrey Vagin" <avagin@openvz.org>,
	davem <davem@davemloft.net>,
	dwindsor@gmail.com, elena.reshetova@intel.com,
	"Herbert Xu" <herbert@gondor.apana.org.au>,
	johannes.berg@intel.com, LKML <linux-kernel@vger.kernel.org>,
	"network dev" <netdev@vger.kernel.org>,
	syzkaller-bugs@googlegroups.com,
	"Américo Wang" <xiyou.wangcong@gmail.com>
Subject: Re: KASAN: stack-out-of-bounds Read in __nla_put
Date: Wed, 17 Jan 2018 08:59:01 -0800	[thread overview]
Message-ID: <7b70f69c-2b8c-f031-83d8-d53b96164d12@gmail.com> (raw)
In-Reply-To: <CADvbK_dhz36U7DbNTMimS47iQD3Ayx-W+aVGp6bOt_ByY350yw@mail.gmail.com>

On 1/17/18 2:39 AM, Xin Long wrote:
> I guess you need to move up your memset(0) a little bit:
> 
> @@ -2427,6 +2443,7 @@ int netlink_rcv_skb(struct sk_buff *skb, int
> (*cb)(struct sk_buff *,
>                 nlh = nlmsg_hdr(skb);
>                 err = 0;
> 
> +               memset(&extack, 0, sizeof(extack));
>                 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
>                         return 0;
> 
> @@ -2438,7 +2455,6 @@ int netlink_rcv_skb(struct sk_buff *skb, int
> (*cb)(struct sk_buff *,
>                 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
>                         goto ack;
> 
> -               memset(&extack, 0, sizeof(extack));
>                 err = cb(skb, nlh, &extack);
> 
> So that 'goto ack's won't skip it. :-)
> 

you are correct. Can you submit a patch to do that?

  reply	other threads:[~2018-01-17 16:59 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-16 17:58 KASAN: stack-out-of-bounds Read in __nla_put syzbot
2018-01-17 10:39 ` Xin Long
2018-01-17 16:59   ` David Ahern [this message]
2018-01-17 17:10     ` Xin Long

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