From: Eric Dumazet <eric.dumazet@gmail.com>
To: Cong Wang <xiyou.wangcong@gmail.com>, netdev@vger.kernel.org
Cc: syzbot+5af9a90dad568aa9f611@syzkaller.appspotmail.com,
syzbot+2f07903a5b05e7f36410@syzkaller.appspotmail.com,
Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [Patch net] net_sched: fix datalen for ematch
Date: Wed, 22 Jan 2020 15:45:34 -0800 [thread overview]
Message-ID: <317521e6-07f5-c32a-66dd-8aa499ae80d7@gmail.com> (raw)
In-Reply-To: <20200122234203.15441-1-xiyou.wangcong@gmail.com>
On 1/22/20 3:42 PM, Cong Wang wrote:
> syzbot reported an out-of-bound access in em_nbyte. As initially
> analyzed by Eric, this is because em_nbyte sets its own em->datalen
> in em_nbyte_change() other than the one specified by user, but this
> value gets overwritten later by its caller tcf_em_validate().
> We should leave em->datalen untouched to respect their choices.
>
> I audit all the in-tree ematch users, all of those implement
> ->change() set em->datalen, so we can just avoid setting it twice
> in this case.
>
> Reported-and-tested-by: syzbot+5af9a90dad568aa9f611@syzkaller.appspotmail.com
> Reported-by: syzbot+2f07903a5b05e7f36410@syzkaller.appspotmail.com
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Cc: Eric Dumazet <eric.dumazet@gmail.com>
> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
> ---
>
SGTM, thanks.
Reviewed-by: Eric Dumazet <edumazet@google.com>
next prev parent reply other threads:[~2020-01-22 23:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-22 23:42 [Patch net] net_sched: fix datalen for ematch Cong Wang
2020-01-22 23:45 ` Eric Dumazet [this message]
2020-01-23 20:35 ` David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=317521e6-07f5-c32a-66dd-8aa499ae80d7@gmail.com \
--to=eric.dumazet@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=syzbot+2f07903a5b05e7f36410@syzkaller.appspotmail.com \
--cc=syzbot+5af9a90dad568aa9f611@syzkaller.appspotmail.com \
--cc=xiyou.wangcong@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).