lkml.org 
[lkml]   [2021]   [Jul]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATH v2] scsi: scsi_dh_rdac: Avoid crash during rdac_bus_attach
From
Date
On 7/28/21 7:24 AM, yebin wrote:
> On 2021/7/23 12:04, Bart Van Assche wrote:
>> On 1/12/21 10:31 PM, Ye Bin wrote:
>>>       sdev->handler_data = NULL;
>>> +    synchronize_rcu();
>>>       kfree(h);
>> What is the purpose of the new synchronize_rcu() call?
> Thanks for your reply.
> Yes, I add new synchronize_rcu() call is to wait until *h is no longer
> in use. If free
> "h" right now , mybe lead to UAF.
>> If its purpose is
>> to wait until *h is no longer in use, please use kfree_rcu() instead.
> struct rdac_dh_data {
>         struct list_head        node;
>         .....
> }
> As rdac_dh_data.node type is "struct list_head", but  kfree_rcu the
> first parameter type is
> "struct rcu_head". So we can only use synchronize_rcu() at here.

Ah, that's right. Hence:

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

\
 
 \ /
  Last update: 2021-07-28 23:55    [W:0.040 / U:0.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site