> > From: liuyacan <liuyacan@xxxxxxxxxxxxxxxx>
> >
> > In the process of checking whether RDMAv2 is available, the current
> > implementation first sets ini->smcrv2.ib_dev_v2, and then allocates
> > smc buf desc, but the latter may fail. Unfortunately, the caller
> > will only check the former. In this case, a NULL pointer reference
> > will occur in smc_clc_send_confirm_accept() when accessing
> > conn->rmb_desc.
> >
> > This patch does two things:
> > 1. Use the return code to determine whether V2 is available.
> > 2. If the return code is NODEV, continue to check whether V1 is
> > available.
> >
> > Fixes: e49300a6bf62 ("net/smc: add listen processing for SMC-Rv2")
> > Signed-off-by: liuyacan <liuyacan@xxxxxxxxxxxxxxxx>
> > ---
>
> I am not happy with this patch. You are right that this is a problem,
> but the fix should be much simpler: set ini->smcrv2.ib_dev_v2 = NULL in
> smc_find_rdma_v2_device_serv() after the not_found label, just like it is
> done in a similar way for the ISM device in smc_find_ism_v1_device_serv().
>
> Your patch changes many more things, and beside that you eliminated the calls
> to smc_find_ism_store_rc() completely, which is not correct.
>
> Since your patch was already applied (btw. 3:20 hours after you submitted it),
> please revert it and resend. Thank you.
I also have considered this way, one question is that do we need to do more roll
back work before V1 check?
Specifically, In smc_find_rdma_v2_device_serv(), there are the following steps:
1. smc_listen_rdma_init()
1.1 smc_conn_create()
1.2 smc_buf_create() --> may fail
2. smc_listen_rdma_reg() --> may fail
When later steps fail, Do we need to roll back previous steps?
Thank you.
