Messages in this thread | | | Date | Sun, 21 Jun 2020 10:12:27 +0300 | From | Leon Romanovsky <> | Subject | Re: [PATCH v3] IB/sa: Resolving use-after-free in ib_nl_send_msg |
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On Wed, Jun 17, 2020 at 03:23:00PM -0300, Jason Gunthorpe wrote: > 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.
It means that the state machine is wrong, not complete.
> > 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
I have same feeling for now, but it will flip if new fixes be in this area.
Thanks
> > Jason
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