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> --- net/smc/af_smc.c | 44 +++++++++++++++++++++++++++----------------- 1 file changed, 27 insertions(+), 17 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 45a24d242..d3de54b70 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -2093,13 +2093,13 @@ static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first) return 0; } -static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc, - struct smc_clc_msg_proposal *pclc, - struct smc_init_info *ini) +static int smc_find_rdma_v2_device_serv(struct smc_sock *new_smc, + struct smc_clc_msg_proposal *pclc, + struct smc_init_info *ini) { struct smc_clc_v2_extension *smc_v2_ext; u8 smcr_version; - int rc; + int rc = 0; if (!(ini->smcr_version & SMC_V2) || !smcr_indicated(ini->smc_type_v2)) goto not_found; @@ -2117,26 +2117,31 @@ static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc, ini->smcrv2.saddr = new_smc->clcsock->sk->sk_rcv_saddr; ini->smcrv2.daddr = smc_ib_gid_to_ipv4(smc_v2_ext->roce); rc = smc_find_rdma_device(new_smc, ini); - if (rc) { - smc_find_ism_store_rc(rc, ini); + if (rc) goto not_found; - } + if (!ini->smcrv2.uses_gateway) memcpy(ini->smcrv2.nexthop_mac, pclc->lcl.mac, ETH_ALEN); smcr_version = ini->smcr_version; ini->smcr_version = SMC_V2; rc = smc_listen_rdma_init(new_smc, ini); - if (!rc) - rc = smc_listen_rdma_reg(new_smc, ini->first_contact_local); - if (!rc) - return; - ini->smcr_version = smcr_version; - smc_find_ism_store_rc(rc, ini); + if (rc) { + ini->smcr_version = smcr_version; + goto not_found; + } + rc = smc_listen_rdma_reg(new_smc, ini->first_contact_local); + if (rc) { + ini->smcr_version = smcr_version; + goto not_found; + } + return 0; not_found: + rc = rc ?: SMC_CLC_DECL_NOSMCDEV; ini->smcr_version &= ~SMC_V2; ini->check_smcrv2 = false; + return rc; } static int smc_find_rdma_v1_device_serv(struct smc_sock *new_smc, @@ -2169,6 +2174,7 @@ static int smc_listen_find_device(struct smc_sock *new_smc, struct smc_init_info *ini) { int prfx_rc; + int rc; /* check for ISM device matching V2 proposed device */ smc_find_ism_v2_device_serv(new_smc, pclc, ini); @@ -2196,14 +2202,18 @@ static int smc_listen_find_device(struct smc_sock *new_smc, return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV; /* check if RDMA V2 is available */ - smc_find_rdma_v2_device_serv(new_smc, pclc, ini); - if (ini->smcrv2.ib_dev_v2) + rc = smc_find_rdma_v2_device_serv(new_smc, pclc, ini); + if (!rc) return 0; + /* skip V1 check if V2 is unavailable for non-Device reason */ + if (rc != SMC_CLC_DECL_NOSMCDEV && + rc != SMC_CLC_DECL_NOSMCRDEV && + rc != SMC_CLC_DECL_NOSMCDDEV) + return rc; + /* check if RDMA V1 is available */ if (!prfx_rc) { - int rc; - rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini); smc_find_ism_store_rc(rc, ini); return (!rc) ? 0 : ini->rc; -- 2.20.1