* [PATCH] rapidio: fix possible UAF when kfifo_alloc() fails
@ 2022-11-17 2:18 Wang Weiyang
2022-11-17 20:45 ` Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: Wang Weiyang @ 2022-11-17 2:18 UTC (permalink / raw)
To: mporter, alex.bou9, akpm, yangyingliang, jakobkoschel, jhubbard,
error27, wangweiyang2
Cc: linux-kernel
If kfifo_alloc() fails in mport_cdev_open(), goto err_fifo and just free
priv. But priv is still in the chdev->file_list, then list traversal
may cause UAF. This fixes the following smatch warning:
drivers/rapidio/devices/rio_mport_cdev.c:1930 mport_cdev_open() warn: '&priv->list' not removed from list
Fixes: e8de370188d0 ("rapidio: add mport char device driver")
Signed-off-by: Wang Weiyang <wangweiyang2@huawei.com>
---
drivers/rapidio/devices/rio_mport_cdev.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c
index 3cc83997a1f8..c66b2c552b38 100644
--- a/drivers/rapidio/devices/rio_mport_cdev.c
+++ b/drivers/rapidio/devices/rio_mport_cdev.c
@@ -1930,6 +1930,9 @@ static int mport_cdev_open(struct inode *inode, struct file *filp)
filp->private_data = priv;
goto out;
err_fifo:
+ mutex_lock(&chdev->file_mutex);
+ list_del(&priv->list);
+ mutex_unlock(&chdev->file_mutex);
kfree(priv);
out:
return ret;
--
2.17.1
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] rapidio: fix possible UAF when kfifo_alloc() fails
2022-11-17 2:18 [PATCH] rapidio: fix possible UAF when kfifo_alloc() fails Wang Weiyang
@ 2022-11-17 20:45 ` Andrew Morton
2022-11-18 9:52 ` wangweiyang
0 siblings, 1 reply; 3+ messages in thread
From: Andrew Morton @ 2022-11-17 20:45 UTC (permalink / raw)
To: Wang Weiyang
Cc: mporter, alex.bou9, yangyingliang, jakobkoschel, jhubbard,
error27, linux-kernel
On Thu, 17 Nov 2022 10:18:02 +0800 Wang Weiyang <wangweiyang2@huawei.com> wrote:
> If kfifo_alloc() fails in mport_cdev_open(), goto err_fifo and just free
> priv. But priv is still in the chdev->file_list, then list traversal
> may cause UAF. This fixes the following smatch warning:
>
> drivers/rapidio/devices/rio_mport_cdev.c:1930 mport_cdev_open() warn: '&priv->list' not removed from list
>
> Fixes: e8de370188d0 ("rapidio: add mport char device driver")
> Signed-off-by: Wang Weiyang <wangweiyang2@huawei.com>
> ---
> drivers/rapidio/devices/rio_mport_cdev.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c
> index 3cc83997a1f8..c66b2c552b38 100644
> --- a/drivers/rapidio/devices/rio_mport_cdev.c
> +++ b/drivers/rapidio/devices/rio_mport_cdev.c
> @@ -1930,6 +1930,9 @@ static int mport_cdev_open(struct inode *inode, struct file *filp)
> filp->private_data = priv;
> goto out;
> err_fifo:
> + mutex_lock(&chdev->file_mutex);
> + list_del(&priv->list);
> + mutex_unlock(&chdev->file_mutex);
> kfree(priv);
> out:
> return ret;
Surely it would be better to avoid adding the new instance onto the
list until the new instance has been fully initialized?
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] rapidio: fix possible UAF when kfifo_alloc() fails
2022-11-17 20:45 ` Andrew Morton
@ 2022-11-18 9:52 ` wangweiyang
0 siblings, 0 replies; 3+ messages in thread
From: wangweiyang @ 2022-11-18 9:52 UTC (permalink / raw)
To: Andrew Morton
Cc: mporter, alex.bou9, yangyingliang, jakobkoschel, jhubbard,
error27, linux-kernel
On 2022/11/18 4:45, Andrew Morton wrote:
> On Thu, 17 Nov 2022 10:18:02 +0800 Wang Weiyang <wangweiyang2@huawei.com> wrote:
>
>> If kfifo_alloc() fails in mport_cdev_open(), goto err_fifo and just free
>> priv. But priv is still in the chdev->file_list, then list traversal
>> may cause UAF. This fixes the following smatch warning:
>>
>> drivers/rapidio/devices/rio_mport_cdev.c:1930 mport_cdev_open() warn: '&priv->list' not removed from list
>>
>> Fixes: e8de370188d0 ("rapidio: add mport char device driver")
>> Signed-off-by: Wang Weiyang <wangweiyang2@huawei.com>
>> ---
>> drivers/rapidio/devices/rio_mport_cdev.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c
>> index 3cc83997a1f8..c66b2c552b38 100644
>> --- a/drivers/rapidio/devices/rio_mport_cdev.c
>> +++ b/drivers/rapidio/devices/rio_mport_cdev.c
>> @@ -1930,6 +1930,9 @@ static int mport_cdev_open(struct inode *inode, struct file *filp)
>> filp->private_data = priv;
>> goto out;
>> err_fifo:
>> + mutex_lock(&chdev->file_mutex);
>> + list_del(&priv->list);
>> + mutex_unlock(&chdev->file_mutex);
>> kfree(priv);
>> out:
>> return ret;
>
> Surely it would be better to avoid adding the new instance onto the
> list until the new instance has been fully initialized?
>
Thanks for your review. I'll send out a v2 patch later.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-11-18 9:53 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2022-11-17 2:18 [PATCH] rapidio: fix possible UAF when kfifo_alloc() fails Wang Weiyang
2022-11-17 20:45 ` Andrew Morton
2022-11-18 9:52 ` wangweiyang
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