Messages in this thread | | | Date | Wed, 17 Jun 2020 15:23:00 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH v3] IB/sa: Resolving use-after-free in ib_nl_send_msg |
| |
On Wed, Jun 17, 2020 at 08:17:39AM +0300, Leon Romanovsky wrote: > > My thoughts that everything here hints me that state machine and > locking are implemented wrongly. In ideal world, the expectation > is that REQ message will have a state in it (PREPARED, SENT, ACK > e.t.c.) and list manipulations are done accordingly with proper > locks, while rdma_nl_multicast() is done outside of the locks.
It can't be done outside the lock without creating races - once rdma_nl_multicast happens it is possible for the other leg of the operation to begin processing.
The list must be updated before this happens.
What is missing here is refcounting - the lifetime model of this data is too implicit, but it is not worth adding I think
Jason
| |