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From: Ji-Hun Kim <ji_hun.kim@samsung.com>
To: baijiaju1990@gmail.com, gregkh@linuxfoundation.org,
	forest@alittletooquiet.net
Cc: devel@driverdev.osuosl.org, y.k.oh@samsung.com,
	kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org,
	julia.lawall@lip6.fr, santhameena13@gmail.com
Subject: Re: [PATCH] staging: vt6655: check for memory allocation failures
Date: Thu, 29 Mar 2018 01:56:37 +0000	[thread overview]
Message-ID: <20180329015637.GA9416@ubuntu> (raw)
In-Reply-To: <fc4cd041-f8b4-f799-916d-9df790efbba7@gmail.com>

On Wed, Mar 28, 2018 at 05:55:57PM +0800, Jia-Ju Bai wrote:
> >@@ -646,7 +649,8 @@ static void device_init_td1_ring(struct vnt_private *priv)
> >  	     i++, curr += sizeof(struct vnt_tx_desc)) {
> >  		desc = &priv->apTD1Rings[i];
> >  		desc->td_info = kzalloc(sizeof(*desc->td_info), GFP_KERNEL);
> >-
> >+		if (WARN_ON(!desc->td_info))
> >+			return;
> >  		desc->td_info->buf = priv->tx1_bufs + i * PKT_BUF_SZ;
> >  		desc->td_info->buf_dma = priv->tx_bufs_dma1 + i * PKT_BUF_SZ;
> 
> I think the bugs you found are right.
> But your patch is not correct, because it is dangerous to return directly.
> I think you should return an error and then implement error handling
> code for these functions.
> 
Yes, it needs to free previous allocated values in the for loop. Directly
return could make memory leaks. I am going to make patch v2. 

- Delete WARN_ON which could make crashes on some machines.
- Add freeing sequences for previously allocated memory when kzalloc()
  failed instead of returning directly.

Does these changes would be fine on this bug?

WARNING: multiple messages have this Message-ID (diff)
From: Ji-Hun Kim <ji_hun.kim@samsung.com>
To: baijiaju1990@gmail.com, gregkh@linuxfoundation.org,
	forest@alittletooquiet.net
Cc: devel@driverdev.osuosl.org, y.k.oh@samsung.com,
	kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org,
	julia.lawall@lip6.fr, santhameena13@gmail.com
Subject: Re: [PATCH] staging: vt6655: check for memory allocation failures
Date: Thu, 29 Mar 2018 10:56:37 +0900	[thread overview]
Message-ID: <20180329015637.GA9416@ubuntu> (raw)
In-Reply-To: <fc4cd041-f8b4-f799-916d-9df790efbba7@gmail.com>

On Wed, Mar 28, 2018 at 05:55:57PM +0800, Jia-Ju Bai wrote:
> >@@ -646,7 +649,8 @@ static void device_init_td1_ring(struct vnt_private *priv)
> >  	     i++, curr += sizeof(struct vnt_tx_desc)) {
> >  		desc = &priv->apTD1Rings[i];
> >  		desc->td_info = kzalloc(sizeof(*desc->td_info), GFP_KERNEL);
> >-
> >+		if (WARN_ON(!desc->td_info))
> >+			return;
> >  		desc->td_info->buf = priv->tx1_bufs + i * PKT_BUF_SZ;
> >  		desc->td_info->buf_dma = priv->tx_bufs_dma1 + i * PKT_BUF_SZ;
> 
> I think the bugs you found are right.
> But your patch is not correct, because it is dangerous to return directly.
> I think you should return an error and then implement error handling
> code for these functions.
> 
Yes, it needs to free previous allocated values in the for loop. Directly
return could make memory leaks. I am going to make patch v2. 

- Delete WARN_ON which could make crashes on some machines.
- Add freeing sequences for previously allocated memory when kzalloc()
  failed instead of returning directly.

Does these changes would be fine on this bug?
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  reply	other threads:[~2018-03-29  1:56 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20180328063144epcas1p305216b582520b884b09c93a7ad591660@epcas1p3.samsung.com>
2018-03-28  6:31 ` [PATCH] staging: vt6655: check for memory allocation failures Ji-Hun Kim
2018-03-28  6:31   ` Ji-Hun Kim
2018-03-28  8:33   ` Greg KH
2018-03-28  8:33     ` Greg KH
2018-03-28  9:55   ` Jia-Ju Bai
2018-03-28  9:55     ` Jia-Ju Bai
2018-03-29  1:56     ` Ji-Hun Kim [this message]
2018-03-29  1:56       ` Ji-Hun Kim

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