netdev - [PATCH net-next 1/1] net/smc: fix double kfree in smc_listen

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Date:   Thu, 17 Sep 2020 22:46:02 +0200
From:   Karsten Graul <kgraul@...ux.ibm.com>
To:     davem@...emloft.net
Cc:     netdev@...r.kernel.org, linux-s390@...r.kernel.org,
        heiko.carstens@...ibm.com, raspl@...ux.ibm.com,
        ubraun@...ux.ibm.com
Subject: [PATCH net-next 1/1] net/smc: fix double kfree in smc_listen_work()

From: Ursula Braun <ubraun@...ux.ibm.com>

If smc_listen_rmda_finish() returns with an error, the storage
addressed by 'buf' is freed a second time.
Consolidate freeing under a common label and jump to that label.

Fixes: 6bb14e48ee8d ("net/smc: dynamic allocation of CLC proposal buffer")
Reported-by: Dan Carpenter <dan.carpenter@...cle.com>
Signed-off-by: Ursula Braun <ubraun@...ux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@...ux.ibm.com>
---
 net/smc/af_smc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index f5bececfedaa..ed8f97166be9 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1371,7 +1371,6 @@ static void smc_listen_work(struct work_struct *work)
 	}
 
 	/* finish worker */
-	kfree(buf);
 	if (!ism_supported) {
 		rc = smc_listen_rdma_finish(new_smc, &cclc,
 					    ini.first_contact_local);
@@ -1381,12 +1380,13 @@ static void smc_listen_work(struct work_struct *work)
 	}
 	smc_conn_save_peer_info(new_smc, &cclc);
 	smc_listen_out_connected(new_smc);
-	return;
+	goto out_free;
 
 out_unlock:
 	mutex_unlock(&smc_server_lgr_pending);
 out_decl:
 	smc_listen_decline(new_smc, rc, ini.first_contact_local);
+out_free:
 	kfree(buf);
 }
 
-- 
2.17.1