Re: [PATCHv2] char:ipmi: Free ipmi_recv_msg messages from the linked list,recv_msgs for the function,ipmi_release in the file,ipmi_devintf.c

From: Corey Minyard
Date: Fri Jan 23 2015 - 14:00:42 EST


On 01/23/2015 12:27 PM, nick wrote:
> Corney,
> Hope this patch fixes the issue. Sorry about missing that kfree
> being required. :(

Well, the kfree needs to be after the free of the messages. You can't
use an item after you free it.

-corey

> Nick
>
>
> On 2015-01-23 01:02 PM, Nicholas Krause wrote:
>> This adds a loop through the elements in the linked list, recv_msgs using
>> list_for_entry_safe in order to free messages in this list. In addition
>> we are using the safe version of this marco in order to prevent use after
>> bugs related to deleting the element we are on currently by holding a
>> pointer to the next element after the current one we are on and freeing
>> with the function, ipmi_free_recv_msg internally in this loop.
>>
>> Signed-off-by: Nicholas Krause <xerofoify@xxxxxxxxx>
>> ---
>> drivers/char/ipmi/ipmi_devintf.c | 7 ++++++-
>> 1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/char/ipmi/ipmi_devintf.c b/drivers/char/ipmi/ipmi_devintf.c
>> index ec318bf..a625510 100644
>> --- a/drivers/char/ipmi/ipmi_devintf.c
>> +++ b/drivers/char/ipmi/ipmi_devintf.c
>> @@ -157,14 +157,19 @@ static int ipmi_release(struct inode *inode, struct file *file)
>> {
>> struct ipmi_file_private *priv = file->private_data;
>> int rv;
>> + struct ipmi_recv_msg *msg, *next;
>>
>> rv = ipmi_destroy_user(priv->user);
>> if (rv)
>> return rv;
>>
>> - /* FIXME - free the messages in the list. */
>> kfree(priv);
>>
>> + list_for_each_entry_safe(msg, next, &priv->recv_msgs, link) {
>> + ipmi_free_recv_msg(msg);
>> + }
>> +
>> +
>> return 0;
>> }
>>
>>

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