On 23/05/2022 07:50, liuyacan@xxxxxxxxxxxxxxxx wrote: > 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.