net/smc: fix null pointer dereference in smc_listen_decline()

smc_listen_work() calls smc_listen_decline() on label out_decl,
providing the ini pointer variable. But this pointer can still be null
when the label out_decl is reached.
Fix this by checking the ini variable in smc_listen_work() and call
smc_listen_decline() with the result directly.

Fixes: a7c9c5f4af7f ("net/smc: CLC accept / confirm V2")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 82be0bd0f6e8135a5d159e8a1620ef23c3986413..e9f487c8c6d55d3c6b335a5b105f3b382ff1d8ca 100644 (file)
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1317,10 +1317,10 @@ static void smc_listen_out_err(struct smc_sock *new_smc)
 
 /* listen worker: decline and fall back if possible */
 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
-                              struct smc_init_info *ini, u8 version)
+                              int local_first, u8 version)
 {
        /* RDMA setup failed, switch back to TCP */
-       if (ini->first_contact_local)
+       if (local_first)
                smc_lgr_cleanup_early(&new_smc->conn);
        else
                smc_conn_free(&new_smc->conn);
@@ -1768,7 +1768,8 @@ static void smc_listen_work(struct work_struct *work)
 out_unlock:
        mutex_unlock(&smc_server_lgr_pending);
 out_decl:
-       smc_listen_decline(new_smc, rc, ini, version);
+       smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0,
+                          version);
 out_free:
        kfree(ini);
        kfree(buf);