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Message-ID: <e216ce10-c345-811a-2279-0ef248c9485f@quicinc.com>
Date: Wed, 28 Feb 2024 15:42:34 +0530
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Subject: Re: [PATCH] usb: xhci: Add error handling in xhci_map_urb_for_dma
Content-Language: en-US
To: Sergei Shtylyov <sergei.shtylyov@gmail.com>,
        Greg Kroah-Hartman
	<gregkh@linuxfoundation.org>,
        Mathias Nyman <mathias.nyman@intel.com>
CC: <linux-kernel@vger.kernel.org>, <linux-usb@vger.kernel.org>,
        <stable@vger.kernel.org>
References: <20240228083343.3101303-1-quic_prashk@quicinc.com>
 <e4f87b6b-4561-8058-3449-2ff9086c81a4@gmail.com>
From: Prashanth K <quic_prashk@quicinc.com>
In-Reply-To: <e4f87b6b-4561-8058-3449-2ff9086c81a4@gmail.com>
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On 28-02-24 02:31 pm, Sergei Shtylyov wrote:
> On 2/28/24 11:33 AM, Prashanth K wrote:
> 
>> Currently xhci_map_urb_for_dma() creates a temporary buffer
>> and copies the SG list to the new linear buffer. But if the
>> kzalloc_node() fails, then the following sg_pcopy_to_buffer()
>> can lead to crash since it tries to memcpy to NULL pointer.
>> So return -EAGAIN if kzalloc returns null pointer.
>>
>> Cc: <stable@vger.kernel.org> # 5.11
>> Fixes: 2017a1e58472 ("usb: xhci: Use temporary buffer to consolidate SG")
>> Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
>> ---
>>   drivers/usb/host/xhci.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
>> index c057c42c36f4..0597a60bec34 100644
>> --- a/drivers/usb/host/xhci.c
>> +++ b/drivers/usb/host/xhci.c
>> @@ -1218,6 +1218,9 @@ static int xhci_map_temp_buffer(struct usb_hcd *hcd, struct urb *urb)
>>   	temp = kzalloc_node(buf_len, GFP_ATOMIC,
>>   			    dev_to_node(hcd->self.sysdev));
>>   
> 
>     I don't think we need an empty line here.
> 
>> +	if (!temp)
>> +		return -EAGAIN;
> 
>     Not -ENOMEM?
Yea that sounds better, will update in next patch.
Thanks!