From: D. Wythe <alibuda@xxxxxxxxxxxxxxxxx> commit 0537f0a2151375dcf90c1bbfda6a0aaf57164e89 upstream. The main reason for this unexpected SMC_CLC_DECL_ERR_REGRMB in client dues to following execution sequence: Server Conn A: Server Conn B: Client Conn B: smc_lgr_unregister_conn smc_lgr_register_conn smc_clc_send_accept -> smc_rtoken_add smcr_buf_unuse -> Client Conn A: smc_rtoken_delete smc_lgr_unregister_conn() makes current link available to assigned to new incoming connection, while smcr_buf_unuse() has not executed yet, which means that smc_rtoken_add may fail because of insufficient rtoken_entry, reversing their execution order will avoid this problem. Fixes: 3e034725c0d8 ("net/smc: common functions for RMBs and send buffers") Signed-off-by: D. Wythe <alibuda@xxxxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/smc/smc_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -239,8 +239,8 @@ void smc_conn_free(struct smc_connection if (!lgr) return; smc_cdc_tx_dismiss_slots(conn); - smc_lgr_unregister_conn(conn); smc_buf_unuse(conn); + smc_lgr_unregister_conn(conn); } static void smc_link_clear(struct smc_link *lnk) Patches currently in stable-queue which might be from alibuda@xxxxxxxxxxxxxxxxx are queue-4.14/net-smc-fix-unexpected-smc_clc_decl_err_regrmb-error-cause-by-server.patch queue-4.14/net-smc-fix-unexpected-smc_clc_decl_err_regrmb-error-generated-by-client.patch