OpenE2K/linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

rds: tcp: must use spin_lock_irq* and not spin_lock_bh with rds_tcp_conn_lock

Browse Source 
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: ebeeb1ad9b ("rds: tcp: use rds_destroy_pending() to synchronize
       netns/module teardown and rds connection/workq management")
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Sowmini Varadhan 2018-03-15 03:54:26 -07:00 committed by David S. Miller
parent 3008ba5faa
commit 53d0e83f93
1 changed files with 9 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
net/rds/tcp.c
View File

@ -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,