From: David Miller <davem@davemloft.net>
To: edumazet@google.com
Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH net] inetpeer: fix uninit-value in inet_getpeer
Date: Mon, 09 Apr 2018 10:58:39 -0400 (EDT) [thread overview]
Message-ID: <20180409.105839.445341256424332032.davem@davemloft.net> (raw)
In-Reply-To: <20180409134327.22367-1-edumazet@google.com>
From: Eric Dumazet <edumazet@google.com>
Date: Mon, 9 Apr 2018 06:43:27 -0700
> syzbot/KMSAN reported that p->dtime was read while it was
> not yet initialized in :
>
> delta = (__u32)jiffies - p->dtime;
> if (delta < ttl || !refcount_dec_if_one(&p->refcnt))
> gc_stack[i] = NULL;
>
> This is a false positive, because the inetpeer wont be erased
> from rb-tree if the refcount_dec_if_one(&p->refcnt) does not
> succeed. And this wont happen before first inet_putpeer() call
> for this inetpeer has been done, and ->dtime field is written
> exactly before the refcount_dec_and_test(&p->refcnt).
>
> The KMSAN report was :
...
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: syzbot <syzkaller@googlegroups.com>
Applied, but it looks like we are just adding assignments simply
to placate these reports when the tools and facilities cannot
see through the logic properly.
next prev parent reply other threads:[~2018-04-09 14:58 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-09 13:43 [PATCH net] inetpeer: fix uninit-value in inet_getpeer Eric Dumazet
2018-04-09 14:58 ` David Miller [this message]
2018-04-09 15:08 ` Eric Dumazet
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=20180409.105839.445341256424332032.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=eric.dumazet@gmail.com \
--cc=netdev@vger.kernel.org \
/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