linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Arthur Marsh <arthur.marsh@internode.on.net>
Cc: SCSI development list <linux-scsi@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	CIFS <linux-cifs@vger.kernel.org>,
	"James E.J. Bottomley" <jejb@linux.ibm.com>
Subject: Re: refcount_t: underflow; use-after-free with CIFS umount after scsi-misc commit ef2cc88e2a205b8a11a19e78db63a70d3728cdf5
Date: Sun, 8 Dec 2019 18:23:02 -0800	[thread overview]
Message-ID: <CAHk-=wjj8SQx4YzS8yw7ZJJKiVLBY0g=d8rCSyPCM=8Pzmz+Zg@mail.gmail.com> (raw)
In-Reply-To: <09396dca-3643-9a4b-070a-e7db2a07235e@internode.on.net>

On Sun, Dec 8, 2019 at 5:49 PM Arthur Marsh
<arthur.marsh@internode.on.net> wrote:
>
> This still happens with 5.5.0-rc1:

Does it happen 100% of the time?

Your bisection result looks pretty nonsensical - not that it's
impossible (anything is possible), but it really doesn't look very
likely. Which makes me think maybe it's slightly timing-sensitive or
something?

Would you mind trying to re-do the bisection, and for each kernel try
the mount thing at least a few times before you decide a kernel is
good?

Bisection is very powerful, but if _any_ of the kernels you marked
good weren't really good (they just happened to not trigger the
problem), bisection ends up giving completely the wrong answer. And
with that bisection commit, there's not even a hint of what could have
gone wrong.

             Linus

  reply	other threads:[~2019-12-09  2:23 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-05  3:44 refcount_t: underflow; use-after-free with CIFS umount after scsi-misc commit ef2cc88e2a205b8a11a19e78db63a70d3728cdf5 Arthur Marsh
2019-12-09  1:49 ` Arthur Marsh
2019-12-09  2:23   ` Linus Torvalds [this message]
2019-12-09  2:52     ` Al Viro
2019-12-09  3:10       ` Linus Torvalds
2019-12-09  3:15         ` Linus Torvalds
2019-12-09  3:18     ` Steve French
2019-12-09  3:27       ` Steve French
2019-12-09 14:45     ` Arthur Marsh

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='CAHk-=wjj8SQx4YzS8yw7ZJJKiVLBY0g=d8rCSyPCM=8Pzmz+Zg@mail.gmail.com' \
    --to=torvalds@linux-foundation.org \
    --cc=arthur.marsh@internode.on.net \
    --cc=jejb@linux.ibm.com \
    --cc=linux-cifs@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-scsi@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;
as well as URLs for NNTP newsgroup(s).