Commit f10b4cff authored by Sowmini Varadhan's avatar Sowmini Varadhan Committed by David S. Miller

rds: tcp: atomically purge entries from rds_tcp_conn_list during netns delete

The rds_tcp_kill_sock() function parses the rds_tcp_conn_list
to find the rds_connection entries marked for deletion as part
of the netns deletion under the protection of the rds_tcp_conn_lock.
Since the rds_tcp_conn_list tracks rds_tcp_connections (which
have a 1:1 mapping with rds_conn_path), multiple tc entries in
the rds_tcp_conn_list will map to a single rds_connection, and will
be deleted as part of the rds_conn_destroy() operation that is
done outside the rds_tcp_conn_lock.

The rds_tcp_conn_list traversal done under the protection of
rds_tcp_conn_lock should not leave any doomed tc entries in
the list after the rds_tcp_conn_lock is released, else another
concurrently executiong netns delete (for a differnt netns) thread
may trip on these entries.
Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
Signed-off-by: default avatarSowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: default avatarSantosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 681648e6
...@@ -306,7 +306,8 @@ static void rds_tcp_conn_free(void *arg) ...@@ -306,7 +306,8 @@ static void rds_tcp_conn_free(void *arg)
rdsdebug("freeing tc %p\n", tc); rdsdebug("freeing tc %p\n", tc);
spin_lock_irqsave(&rds_tcp_conn_lock, flags); spin_lock_irqsave(&rds_tcp_conn_lock, flags);
list_del(&tc->t_tcp_node); if (!tc->t_tcp_node_detached)
list_del(&tc->t_tcp_node);
spin_unlock_irqrestore(&rds_tcp_conn_lock, flags); spin_unlock_irqrestore(&rds_tcp_conn_lock, flags);
kmem_cache_free(rds_tcp_conn_slab, tc); kmem_cache_free(rds_tcp_conn_slab, tc);
...@@ -510,8 +511,12 @@ static void rds_tcp_kill_sock(struct net *net) ...@@ -510,8 +511,12 @@ static void rds_tcp_kill_sock(struct net *net)
if (net != c_net || !tc->t_sock) if (net != c_net || !tc->t_sock)
continue; continue;
if (!list_has_conn(&tmp_list, tc->t_cpath->cp_conn)) if (!list_has_conn(&tmp_list, tc->t_cpath->cp_conn)) {
list_move_tail(&tc->t_tcp_node, &tmp_list); list_move_tail(&tc->t_tcp_node, &tmp_list);
} else {
list_del(&tc->t_tcp_node);
tc->t_tcp_node_detached = true;
}
} }
spin_unlock_irq(&rds_tcp_conn_lock); spin_unlock_irq(&rds_tcp_conn_lock);
list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node)
......
...@@ -12,6 +12,7 @@ struct rds_tcp_incoming { ...@@ -12,6 +12,7 @@ struct rds_tcp_incoming {
struct rds_tcp_connection { struct rds_tcp_connection {
struct list_head t_tcp_node; struct list_head t_tcp_node;
bool t_tcp_node_detached;
struct rds_conn_path *t_cpath; struct rds_conn_path *t_cpath;
/* t_conn_path_lock synchronizes the connection establishment between /* t_conn_path_lock synchronizes the connection establishment between
* rds_tcp_accept_one and rds_tcp_conn_path_connect * rds_tcp_accept_one and rds_tcp_conn_path_connect
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment