linux-kernel - Re: 2.6.31-rc5 regression: Oops when USB Serial disconnected while in use

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20090821164843.639aedaf@lxorguk.ukuu.org.uk>
Date:	Fri, 21 Aug 2009 16:48:43 +0100
From:	Alan Cox <alan@...rguk.ukuu.org.uk>
To:	Alan Stern <stern@...land.harvard.edu>
Cc:	Bruno Prémont <bonbons@...ux-vserver.org>,
	Greg KH <greg@...ah.com>,
	Kernel development list <linux-kernel@...r.kernel.org>,
	USB list <linux-usb@...r.kernel.org>,
	"Rafael J. Wysocki" <rjw@...k.pl>
Subject: Re: 2.6.31-rc5 regression: Oops when USB Serial disconnected while
 in use

> Alan, related to this problem is the fact that usb_serial_driver
> doesn't include a "hangup" method.  I'm not sure that making
> serial_hangup() call serial_do_down() is correct, but if it is then
> shouldn't we call port->serial->type->open() afterwards?  Otherwise the
> lower driver can't know that the port is still open.

After a hangup the port isn't open (at the physical level anyway). It may
be re-opened by another open() call later but the original user lost
access to it and shouldn't touch the h/w post hangup completion.

> Furthermore, shouldn't we check ASYNCB_INITIALIZED in serial_close()?

Possibly - I was in the middle of debugging the newest bits when Linus
annoyed me. Certainly there are issues in the current code if you get
a hangup while waiting for open to complete. I fixed that in the patches
I sent Greg but didn't finish debugging it.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/