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Subject: Re: [PATCH V2] usb: tegra: Fix allocation for the FPCI context
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC:     Mathias Nyman <mathias.nyman@intel.com>,
        Thierry Reding <thierry.reding@gmail.com>,
        <linux-tegra@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <stable@vger.kernel.org>
References: <20200712102837.24340-1-jonathanh@nvidia.com>
 <20200715113842.30680-1-jonathanh@nvidia.com>
 <20200723111934.GA1964033@kroah.com>
From:   Jon Hunter <jonathanh@nvidia.com>
Message-ID: <bf4c5600-067d-eaaf-6364-84a23cce497d@nvidia.com>
Date:   Wed, 29 Jul 2020 11:08:04 +0100
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On 23/07/2020 12:19, Greg Kroah-Hartman wrote:
> On Wed, Jul 15, 2020 at 12:38:42PM +0100, Jon Hunter wrote:
>> Commit 5c4e8d3781bc ("usb: host: xhci-tegra: Add support for XUSB
>> context save/restore") is using the IPFS 'num_offsets' value when
>> allocating memory for FPCI context instead of the FPCI 'num_offsets'.
>>
>> After commit cad064f1bd52 ("devres: handle zero size in devm_kmalloc()")
>> was added system suspend started failing on Tegra186. The kernel log
>> showed that the Tegra XHCI driver was crashing on entry to suspend when
>> attempting the save the USB context. On Tegra186, the IPFS context has a
>> zero length but the FPCI content has a non-zero length, and because of
>> the bug in the Tegra XHCI driver we are incorrectly allocating a zero
>> length array for the FPCI context. The crash seen on entering suspend
>> when we attempt to save the FPCI context and following commit
>> cad064f1bd52 ("devres: handle zero size in devm_kmalloc()") this now
>> causes a NULL pointer deference when we access the memory. Fix this by
>> correcting the amount of memory we are allocating for FPCI contexts.
>>
>> Cc: stable@vger.kernel.org
>>
>> Fixes: 5c4e8d3781bc ("usb: host: xhci-tegra: Add support for XUSB context save/restore")
>>
>> Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
>> Acked-by: Thierry Reding <treding@nvidia.com>
>> ---
>>
>> Changes since V1:
>> - Corrected commit message
>> - Added Thierry's ACK
>>
>>  drivers/usb/host/xhci-tegra.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> No cc: to linux-usb@vger?  :(
> 
> I'll go queue this up, but I would have caught it sooner if you had done
> so...

Sorry about that. Thanks for queuing up!
Jon

-- 
nvpublic