From: David Howells dhowells@redhat.com
[ Upstream commit 5399d52233c47905bbf97dcbaa2d7a9cc31670ba ]
AF_RXRPC sockets use UDP ports in encap mode. This causes socket and dst from an incoming packet to get stolen and attached to the UDP socket from whence it is leaked when that socket is closed.
When a network namespace is removed, the wait for dst records to be cleaned up happens before the cleanup of the rxrpc and UDP socket, meaning that the wait never finishes.
Fix this by moving the rxrpc (and, by dependence, the afs) private per-network namespace registrations to the device group rather than subsys group. This allows cached rxrpc local endpoints to be cleared and their UDP sockets closed before we try waiting for the dst records.
The symptom is that lines looking like the following:
unregister_netdevice: waiting for lo to become free
get emitted at regular intervals after running something like the referenced syzbot test.
Thanks to Vadim for tracking this down and work out the fix.
Reported-by: syzbot+df400f2f24a1677cd7e0@syzkaller.appspotmail.com Reported-by: Vadim Fedorenko vfedorenko@novek.ru Fixes: 5271953cad31 ("rxrpc: Use the UDP encap_rcv hook") Signed-off-by: David Howells dhowells@redhat.com Acked-by: Vadim Fedorenko vfedorenko@novek.ru Link: https://lore.kernel.org/r/161196443016.3868642.5577440140646403533.stgit@war... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/afs/main.c | 6 +++--- net/rxrpc/af_rxrpc.c | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/fs/afs/main.c b/fs/afs/main.c index 107427688eddd..8ecb127be63f9 100644 --- a/fs/afs/main.c +++ b/fs/afs/main.c @@ -190,7 +190,7 @@ static int __init afs_init(void) goto error_cache; #endif
- ret = register_pernet_subsys(&afs_net_ops); + ret = register_pernet_device(&afs_net_ops); if (ret < 0) goto error_net;
@@ -210,7 +210,7 @@ static int __init afs_init(void) error_proc: afs_fs_exit(); error_fs: - unregister_pernet_subsys(&afs_net_ops); + unregister_pernet_device(&afs_net_ops); error_net: #ifdef CONFIG_AFS_FSCACHE fscache_unregister_netfs(&afs_cache_netfs); @@ -241,7 +241,7 @@ static void __exit afs_exit(void)
proc_remove(afs_proc_symlink); afs_fs_exit(); - unregister_pernet_subsys(&afs_net_ops); + unregister_pernet_device(&afs_net_ops); #ifdef CONFIG_AFS_FSCACHE fscache_unregister_netfs(&afs_cache_netfs); #endif diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c index 57f835d2442ec..fb7e3fffcb5ef 100644 --- a/net/rxrpc/af_rxrpc.c +++ b/net/rxrpc/af_rxrpc.c @@ -1010,7 +1010,7 @@ static int __init af_rxrpc_init(void) goto error_security; }
- ret = register_pernet_subsys(&rxrpc_net_ops); + ret = register_pernet_device(&rxrpc_net_ops); if (ret) goto error_pernet;
@@ -1055,7 +1055,7 @@ static int __init af_rxrpc_init(void) error_sock: proto_unregister(&rxrpc_proto); error_proto: - unregister_pernet_subsys(&rxrpc_net_ops); + unregister_pernet_device(&rxrpc_net_ops); error_pernet: rxrpc_exit_security(); error_security: @@ -1077,7 +1077,7 @@ static void __exit af_rxrpc_exit(void) unregister_key_type(&key_type_rxrpc); sock_unregister(PF_RXRPC); proto_unregister(&rxrpc_proto); - unregister_pernet_subsys(&rxrpc_net_ops); + unregister_pernet_device(&rxrpc_net_ops); ASSERTCMP(atomic_read(&rxrpc_n_tx_skbs), ==, 0); ASSERTCMP(atomic_read(&rxrpc_n_rx_skbs), ==, 0);