Re: net/rds: use-after-free in inet_create

[Sowmini Varadhan]

On (02/28/17 15:22), Dmitry Vyukov wrote:
> 
> Hello,
> 
> I've got the following report while running syzkaller fuzzer on
> linux-next/8d01c069486aca75b8f6018a759215b0ed0c91f0. So far it
> happened only once. net was somehow deleted from underneath
> inet_create. I've noticed that rds uses sock_create_kern which does
> not take net reference. What is that that must keep net alive then?

The rds_connection (which is where the net pointer is being obtained from)
should keep the connection alive. Did you have the rds[_tcp] modules
loaded at the time of failure? Were there kernel tcp sockets to/from
the 16385 port? any hints on what else the test was doing (was it
running a userspace RDS application that triggered the kernel TCP
connection attempt in the first place)?

--Sowmini