linux-kernel - Re: [PATCH] scsi: megaraid: Fix uninitialized mbox in mega_cmd

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: <yq1v8g8b0e8.fsf@ca-mkp.ca.oracle.com>
Date:   Wed, 31 May 2023 18:38:12 -0400
From:   "Martin K. Petersen" <martin.petersen@...cle.com>
To:     Maximilian Heyne <mheyne@...zon.de>
Cc:     Kashyap Desai <kashyap.desai@...adcom.com>,
        Sumit Saxena <sumit.saxena@...adcom.com>,
        Shivasharan S <shivasharan.srikanteshwara@...adcom.com>,
        "James E.J. Bottomley" <jejb@...ux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        James Bottomley <JBottomley@...allels.com>,
        Adam Radford <aradford@...il.com>,
        Christoph Hellwig <hch@...radead.org>,
        <megaraidlinux.pdl@...adcom.com>, <linux-scsi@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] scsi: megaraid: Fix uninitialized mbox in mega_cmd_done

Hi Maximilian!

> This is similar to commit 7a2ae008a53c ("scsi: megaraid: Fix
> mega_cmd_done() CMDID_INT_CMDS").

That's supposed to be commit 75cb113cd43f, right?

> When cmdid == CMDID_INT_CMDS and status != 0 then mbox is still NULL
> but is dereferenced below.

Is this actually a valid scenario, though? The mbox is only dereferenced
if there is status returned from an attached device. And I am guessing
that a controller-internal command does not talk to any attached device.
Thus status should always be 0 for CMDID_INT_CMDS. I don't have the
megaraid firmware manual so this is pure guesswork on my part. But you
would think we would have come across an invalid deref since the
original 2014 commit made the offending change.

-- 
Martin K. Petersen	Oracle Linux Engineering