From: Michael Ellerman <mpe@ellerman.id.au>
To: Andrew Donnellan <ajd@linux.ibm.com>,
Oliver O'Halloran <oohall@gmail.com>,
linuxppc-dev@lists.ozlabs.org
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Subject: Re: [PATCH 1/2] cpufreq/powernv: Fix use-after-free
Date: Thu, 27 Feb 2020 12:31:11 +1100 [thread overview]
Message-ID: <871rqg3jfk.fsf@mpe.ellerman.id.au> (raw)
In-Reply-To: <33e1d358-caa4-ddbc-895e-4c7a6c282e91@linux.ibm.com>
Andrew Donnellan <ajd@linux.ibm.com> writes:
> On 6/2/20 5:26 pm, Oliver O'Halloran wrote:
>> The cpufreq driver has a use-after-free that we can hit if:
>>
>> a) There's an OCC message pending when the notifier is registered, and
>> b) The cpufreq driver fails to register with the core.
>>
>> When a) occurs the notifier schedules a workqueue item to handle the
>> message. The backing work_struct is located on chips[].throttle and when b)
>> happens we clean up by freeing the array. Once we get to the (now free)
>> queued item and the kernel crashes.
>>
>> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
>> Fixes: c5e29ea ("cpufreq: powernv: Fix bugs in powernv_cpufreq_{init/exit}")
>> Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
>
> This sounds like it needs to go to stable.
I tagged it for stable when applying.
cheers
next prev parent reply other threads:[~2020-02-27 1:33 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-06 6:26 [PATCH 1/2] cpufreq/powernv: Fix use-after-free Oliver O'Halloran
2020-02-06 6:26 ` [PATCH 2/2] cpufreq/powernv: Fix unsafe notifiers Oliver O'Halloran
2020-02-25 6:45 ` Gautham R Shenoy
2020-02-25 6:42 ` [PATCH 1/2] cpufreq/powernv: Fix use-after-free Gautham R Shenoy
2020-02-25 7:03 ` Andrew Donnellan
2020-02-27 1:31 ` Michael Ellerman [this message]
2020-03-17 13:14 ` Michael Ellerman
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