linux-kernel - Re: Issue with qla2xxx_probe

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: <20080430075704M.fujita.tomonori@lab.ntt.co.jp>
Date:	Wed, 30 Apr 2008 07:57:04 +0900
From:	FUJITA Tomonori <fujita.tomonori@....ntt.co.jp>
To:	Alan.Brunelle@...com
Cc:	andrew.vasquez@...gic.com, linux-kernel@...r.kernel.org,
	jens.axboe@...cle.com, linux-driver@...gic.com,
	linux-scsi@...r.kernel.org, James.Bottomley@...eleye.com
Subject: Re: Issue with qla2xxx_probe_one

On Tue, 29 Apr 2008 16:12:51 -0400
"Alan D. Brunelle" <Alan.Brunelle@...com> wrote:

> This is a multi-part message in MIME format.
> --------------050404010600090601000605
> Content-Type: text/plain; charset=ISO-8859-1
> Content-Transfer-Encoding: 7bit
> 
> Andrew Vasquez wrote:
> > On Tue, 29 Apr 2008, Alan D. Brunelle wrote:
> >
> >> I /think/ that there is an issue with this routine /if/ the firmware
> >> images are not loaded properly - on a 16-way ia64 box I am starting to
> >> see this with an up-stream kernel (Jens Axboe's origin/io-cpu-affinity
> >> branch). In any event, it looks to me that :
> >>
> >>         if (qla2x00_initialize_adapter(ha)) {
> >>                 qla_printk(KERN_WARNING, ha,
> >>                     "Failed to initialize adapter\n");
> >>
> >>                 DEBUG2(printk("scsi(%ld): Failed to initialize
> adapter - "
> >>                     "Adapter flags %x.\n",
> >>                     ha->host_no, ha->device_flags));
> >>
> >>                 ret = -ENODEV;
> >>                 goto probe_failed;
> >>         }
> >>
> >> skips around:
> >>
> >>         ret = scsi_add_host(host, &pdev->dev);
> >>
> >> which is needed to properly initialize the freelist (via:
> >> scsi_setup_command_freelist).
> >
> > Wasn't something like this posted recently to linux-scsi:
> >
> > http://lkml.org/lkml/2008/4/27/333
> >
> > this is sitting in scsi-misc-2.6.git:
> >
> > [SCSI] bug fix for free list handling
> >
> http://git.kernel.org/?p=linux/kernel/git/jejb/scsi-misc-2.6.git;a=commitdiff;h=a79cbe1aa5dd695f0ee012ecde1ff88b1192e326
> >
> > which I gather will be pushed soon...
> 
> My apologies for not having seeing that.
> 
> But after looking at it, doesn't it still have a hole?
> 
> o  scsi_setup_command_freelist initializes the free_list list.
> 
> o  It then invokes scsi_get_host_cmd_pool, if this fails there is no
> need to invoke scsi_put_host_cmd_pool (it wasn't gotten).
> 
> o  If scsi_get_host_cmd_pool succeeds but scsi_pool_alloc_command fails,
> it will (correctly) invoke scsi_put_host_cmd_pool.
> 
> However, if either of scsi_get_host_cmd_pool or scsi_put_host_cmd_pool
> happens to fail, we'll end up in scsi_destroy_command_freelist - and
> since the free_list was initialized, the while loop will be bypassed,
> but scsi_put_host_cmd_pool will be invoked an extra time. And this is
> badness, right?

scsi_put_host_cmd_pool doesn't fail but I think that you are right. If
scsi_get_host_cmd_pool or scsi_pool_alloc_command in
scsi_setup_command_freelist fails, we hit the problem.


> Wouldn't the attached patch [boot tested on my previously failing
> system] be correct (and perhaps cleaner - you're not looking at the
> innards of the list data structure to determine things)?

Looks correct to me.
--
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/