Commit 77f838ac authored by Karsten Graul's avatar Karsten Graul Committed by David S. Miller

net/smc: prevent races between smc_lgr_terminate() and smc_conn_free()

To prevent races between smc_lgr_terminate() and smc_conn_free() add an
extra check of the lgr field before accessing it, and cancel a delayed
free_work when a new smc connection is created.
This fixes the problem that free_work cleared the lgr variable but
smc_lgr_terminate() or smc_conn_free() still access it in parallel.
Signed-off-by: default avatarKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: default avatarUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ca8dc133
...@@ -128,6 +128,8 @@ static void smc_lgr_unregister_conn(struct smc_connection *conn) ...@@ -128,6 +128,8 @@ static void smc_lgr_unregister_conn(struct smc_connection *conn)
{ {
struct smc_link_group *lgr = conn->lgr; struct smc_link_group *lgr = conn->lgr;
if (!lgr)
return;
write_lock_bh(&lgr->conns_lock); write_lock_bh(&lgr->conns_lock);
if (conn->alert_token_local) { if (conn->alert_token_local) {
__smc_lgr_unregister_conn(conn); __smc_lgr_unregister_conn(conn);
...@@ -628,6 +630,8 @@ int smc_conn_create(struct smc_sock *smc, bool is_smcd, int srv_first_contact, ...@@ -628,6 +630,8 @@ int smc_conn_create(struct smc_sock *smc, bool is_smcd, int srv_first_contact,
local_contact = SMC_REUSE_CONTACT; local_contact = SMC_REUSE_CONTACT;
conn->lgr = lgr; conn->lgr = lgr;
smc_lgr_register_conn(conn); /* add smc conn to lgr */ smc_lgr_register_conn(conn); /* add smc conn to lgr */
if (delayed_work_pending(&lgr->free_work))
cancel_delayed_work(&lgr->free_work);
write_unlock_bh(&lgr->conns_lock); write_unlock_bh(&lgr->conns_lock);
break; break;
} }
......
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