4.17-stable review patch. If anyone has any objections, please let me know.
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From: Sowmini Varadhan sowmini.varadhan@oracle.com
[ Upstream commit c809195f5523dd4d09403bbb1c9732d548aa0d1e ]
The RDS core module creates rds_connections based on callbacks from rds_loop_transport when sending/receiving packets to local addresses.
These connections will need to be cleaned up when they are created from a netns that is not init_net, and that netns is deleted.
Add the changes aligned with the changes from commit ebeeb1ad9b8a ("rds: tcp: use rds_destroy_pending() to synchronize netns/module teardown and rds connection/workq management") for rds_loop_transport
Reported-and-tested-by: syzbot+4c20b3866171ce8441d2@syzkaller.appspotmail.com Acked-by: Santosh Shilimkar santosh.shilimkar@oracle.com Signed-off-by: Sowmini Varadhan sowmini.varadhan@oracle.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/rds/connection.c | 11 +++++++++- net/rds/loop.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++ net/rds/loop.h | 2 + 3 files changed, 68 insertions(+), 1 deletion(-)
--- a/net/rds/connection.c +++ b/net/rds/connection.c @@ -659,11 +659,19 @@ static void rds_conn_info(struct socket
int rds_conn_init(void) { + int ret; + + ret = rds_loop_net_init(); /* register pernet callback */ + if (ret) + return ret; + rds_conn_slab = kmem_cache_create("rds_connection", sizeof(struct rds_connection), 0, 0, NULL); - if (!rds_conn_slab) + if (!rds_conn_slab) { + rds_loop_net_exit(); return -ENOMEM; + }
rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info); rds_info_register_func(RDS_INFO_SEND_MESSAGES, @@ -676,6 +684,7 @@ int rds_conn_init(void)
void rds_conn_exit(void) { + rds_loop_net_exit(); /* unregister pernet callback */ rds_loop_exit();
WARN_ON(!hlist_empty(rds_conn_hash)); --- a/net/rds/loop.c +++ b/net/rds/loop.c @@ -33,6 +33,8 @@ #include <linux/kernel.h> #include <linux/slab.h> #include <linux/in.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h>
#include "rds_single_path.h" #include "rds.h" @@ -40,6 +42,17 @@
static DEFINE_SPINLOCK(loop_conns_lock); static LIST_HEAD(loop_conns); +static atomic_t rds_loop_unloading = ATOMIC_INIT(0); + +static void rds_loop_set_unloading(void) +{ + atomic_set(&rds_loop_unloading, 1); +} + +static bool rds_loop_is_unloading(struct rds_connection *conn) +{ + return atomic_read(&rds_loop_unloading) != 0; +}
/* * This 'loopback' transport is a special case for flows that originate @@ -165,6 +178,8 @@ void rds_loop_exit(void) struct rds_loop_connection *lc, *_lc; LIST_HEAD(tmp_list);
+ rds_loop_set_unloading(); + synchronize_rcu(); /* avoid calling conn_destroy with irqs off */ spin_lock_irq(&loop_conns_lock); list_splice(&loop_conns, &tmp_list); @@ -177,6 +192,46 @@ void rds_loop_exit(void) } }
+static void rds_loop_kill_conns(struct net *net) +{ + struct rds_loop_connection *lc, *_lc; + LIST_HEAD(tmp_list); + + spin_lock_irq(&loop_conns_lock); + list_for_each_entry_safe(lc, _lc, &loop_conns, loop_node) { + struct net *c_net = read_pnet(&lc->conn->c_net); + + if (net != c_net) + continue; + list_move_tail(&lc->loop_node, &tmp_list); + } + spin_unlock_irq(&loop_conns_lock); + + list_for_each_entry_safe(lc, _lc, &tmp_list, loop_node) { + WARN_ON(lc->conn->c_passive); + rds_conn_destroy(lc->conn); + } +} + +static void __net_exit rds_loop_exit_net(struct net *net) +{ + rds_loop_kill_conns(net); +} + +static struct pernet_operations rds_loop_net_ops = { + .exit = rds_loop_exit_net, +}; + +int rds_loop_net_init(void) +{ + return register_pernet_device(&rds_loop_net_ops); +} + +void rds_loop_net_exit(void) +{ + unregister_pernet_device(&rds_loop_net_ops); +} + /* * This is missing .xmit_* because loop doesn't go through generic * rds_send_xmit() and doesn't call rds_recv_incoming(). .listen_stop and @@ -194,4 +249,5 @@ struct rds_transport rds_loop_transport .inc_free = rds_loop_inc_free, .t_name = "loopback", .t_type = RDS_TRANS_LOOP, + .t_unloading = rds_loop_is_unloading, }; --- a/net/rds/loop.h +++ b/net/rds/loop.h @@ -5,6 +5,8 @@ /* loop.c */ extern struct rds_transport rds_loop_transport;
+int rds_loop_net_init(void); +void rds_loop_net_exit(void); void rds_loop_exit(void);
#endif