From 53d0e83f9329aa51dcc205b514dbee05cb4df309 Mon Sep 17 00:00:00 2001 From: Sowmini Varadhan Date: Thu, 15 Mar 2018 03:54:26 -0700 Subject: [PATCH] rds: tcp: must use spin_lock_irq* and not spin_lock_bh with rds_tcp_conn_lock rds_tcp_connection allocation/free management has the potential to be called from __rds_conn_create after IRQs have been disabled, so spin_[un]lock_bh cannot be used with rds_tcp_conn_lock. Bottom-halves that need to synchronize for critical sections protected by rds_tcp_conn_lock should instead use rds_destroy_pending() correctly. Reported-by: syzbot+c68e51bb5e699d3f8d91@syzkaller.appspotmail.com Fixes: ebeeb1ad9b8a ("rds: tcp: use rds_destroy_pending() to synchronize netns/module teardown and rds connection/workq management") Signed-off-by: Sowmini Varadhan Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller --- net/rds/tcp.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/net/rds/tcp.c b/net/rds/tcp.c index eb04e7fa2467..08ea9cd5c2f6 100644 --- a/net/rds/tcp.c +++ b/net/rds/tcp.c @@ -272,13 +272,14 @@ static int rds_tcp_laddr_check(struct net *net, __be32 addr) static void rds_tcp_conn_free(void *arg) { struct rds_tcp_connection *tc = arg; + unsigned long flags; rdsdebug("freeing tc %p\n", tc); - spin_lock_bh(&rds_tcp_conn_lock); + spin_lock_irqsave(&rds_tcp_conn_lock, flags); if (!tc->t_tcp_node_detached) list_del(&tc->t_tcp_node); - spin_unlock_bh(&rds_tcp_conn_lock); + spin_unlock_irqrestore(&rds_tcp_conn_lock, flags); kmem_cache_free(rds_tcp_conn_slab, tc); } @@ -308,13 +309,13 @@ static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp) rdsdebug("rds_conn_path [%d] tc %p\n", i, conn->c_path[i].cp_transport_data); } - spin_lock_bh(&rds_tcp_conn_lock); + spin_lock_irq(&rds_tcp_conn_lock); for (i = 0; i < RDS_MPATH_WORKERS; i++) { tc = conn->c_path[i].cp_transport_data; tc->t_tcp_node_detached = false; list_add_tail(&tc->t_tcp_node, &rds_tcp_conn_list); } - spin_unlock_bh(&rds_tcp_conn_lock); + spin_unlock_irq(&rds_tcp_conn_lock); fail: if (ret) { for (j = 0; j < i; j++) @@ -527,7 +528,7 @@ static void rds_tcp_kill_sock(struct net *net) rtn->rds_tcp_listen_sock = NULL; rds_tcp_listen_stop(lsock, &rtn->rds_tcp_accept_w); - spin_lock_bh(&rds_tcp_conn_lock); + spin_lock_irq(&rds_tcp_conn_lock); list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) { struct net *c_net = read_pnet(&tc->t_cpath->cp_conn->c_net); @@ -540,7 +541,7 @@ static void rds_tcp_kill_sock(struct net *net) tc->t_tcp_node_detached = true; } } - spin_unlock_bh(&rds_tcp_conn_lock); + spin_unlock_irq(&rds_tcp_conn_lock); list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) rds_conn_destroy(tc->t_cpath->cp_conn); } @@ -588,7 +589,7 @@ static void rds_tcp_sysctl_reset(struct net *net) { struct rds_tcp_connection *tc, *_tc; - spin_lock_bh(&rds_tcp_conn_lock); + spin_lock_irq(&rds_tcp_conn_lock); list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) { struct net *c_net = read_pnet(&tc->t_cpath->cp_conn->c_net); @@ -598,7 +599,7 @@ static void rds_tcp_sysctl_reset(struct net *net) /* reconnect with new parameters */ rds_conn_path_drop(tc->t_cpath, false); } - spin_unlock_bh(&rds_tcp_conn_lock); + spin_unlock_irq(&rds_tcp_conn_lock); } static int rds_tcp_skbuf_handler(struct ctl_table *ctl, int write, -- 2.20.1