Re: [BUG] net: rds: rds_send_probe memory leak

[Greg KH <gregkh@linuxfoundation.org>]

On Sun, Mar 14, 2021 at 11:23:10AM +0300, Fatih Yildirim wrote:
> Hi Santosh,
> 
> I've been working on a memory leak bug reported by syzbot.
> https://syzkaller.appspot.com/bug?id=39b72114839a6dbd66c1d2104522698a813f9ae2
> 
> It seems that memory allocated in rds_send_probe function is not freed.
> 
> Let me share my observations.
> rds_message is allocated at the beginning of rds_send_probe function.
> Then it is added to cp_send_queue list of rds_conn_path and refcount
> is increased by one.
> Next, in rds_send_xmit function it is moved from cp_send_queue list to
> cp_retrans list, and again refcount is increased by one.
> Finally in rds_loop_xmit function refcount is increased by one.
> So, total refcount is 4.
> However, rds_message_put is called three times, in rds_send_probe,
> rds_send_remove_from_sock and rds_send_xmit functions. It seems that
> one more rds_message_put is needed.
> Would you please check and share your comments on this issue?

Do you have a proposed patch that syzbot can test to verify if this is
correct or not?

thanks,

gre gk-h