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authorDavid Howells <dhowells@redhat.com>2021-01-29 23:53:50 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-02-10 09:21:06 +0100
commitd154251980f49177abdca20230116d120ef0b215 (patch)
tree06ae37a01e078dfb7e4e8b6f65a2167fb13fa569 /net
parente923e82dfaeb304d061923698522b982d7c297ed (diff)
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rxrpc: Fix deadlock around release of dst cached on udp tunnel
[ 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@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
-rw-r--r--net/rxrpc/af_rxrpc.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index 57f835d2442e..fb7e3fffcb5e 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 @@ error_key_type:
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);