[PATCH AUTOSEL 5.15 10/69] bpf, sockmap: Fix sk->sk_forward_alloc warn_on in sk_stream_kill_queues
From: Sasha Levin <sashal@kernel.org>
Date: 2022-08-11 16:13:32
Also in:
bpf, lkml, stable
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), bpf [l7 framework] (sockmap), networking [general], networking [sockets], networking [tcp], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, John Fastabend, Jakub Sitnicki, Jiayuan Chen, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Neal Cardwell, Linus Torvalds
From: Wang Yufen <redacted> [ Upstream commit d8616ee2affcff37c5d315310da557a694a3303d ] During TCP sockmap redirect pressure test, the following warning is triggered: WARNING: CPU: 3 PID: 2145 at net/core/stream.c:205 sk_stream_kill_queues+0xbc/0xd0 CPU: 3 PID: 2145 Comm: iperf Kdump: loaded Tainted: G W 5.10.0+ #9 Call Trace: inet_csk_destroy_sock+0x55/0x110 inet_csk_listen_stop+0xbb/0x380 tcp_close+0x41b/0x480 inet_release+0x42/0x80 __sock_release+0x3d/0xa0 sock_close+0x11/0x20 __fput+0x9d/0x240 task_work_run+0x62/0x90 exit_to_user_mode_prepare+0x110/0x120 syscall_exit_to_user_mode+0x27/0x190 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The reason we observed is that: When the listener is closing, a connection may have completed the three-way handshake but not accepted, and the client has sent some packets. The child sks in accept queue release by inet_child_forget()->inet_csk_destroy_sock(), but psocks of child sks have not released. To fix, add sock_map_destroy to release psocks. Signed-off-by: Wang Yufen <redacted> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jakub Sitnicki <jakub@cloudflare.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20220524075311.649153-1-wangyufen@huawei.com (local) Signed-off-by: Sasha Levin <sashal@kernel.org> --- include/linux/bpf.h | 1 + include/linux/skmsg.h | 1 + net/core/skmsg.c | 1 + net/core/sock_map.c | 23 +++++++++++++++++++++++ net/ipv4/tcp_bpf.c | 1 + 5 files changed, 27 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 818cd594e922..84efd8dd139d 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h@@ -2022,6 +2022,7 @@ int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog); int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype); int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value, u64 flags); void sock_map_unhash(struct sock *sk); +void sock_map_destroy(struct sock *sk); void sock_map_close(struct sock *sk, long timeout); #else static inline int bpf_prog_offload_init(struct bpf_prog *prog,
diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
index 73bedd128d52..ad3b798d9944 100644
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h@@ -96,6 +96,7 @@ struct sk_psock { spinlock_t link_lock; refcount_t refcnt; void (*saved_unhash)(struct sock *sk); + void (*saved_destroy)(struct sock *sk); void (*saved_close)(struct sock *sk, long timeout); void (*saved_write_space)(struct sock *sk); void (*saved_data_ready)(struct sock *sk);
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index ede0af308f40..2742d8e4dd82 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c@@ -716,6 +716,7 @@ struct sk_psock *sk_psock_init(struct sock *sk, int node) psock->eval = __SK_NONE; psock->sk_proto = prot; psock->saved_unhash = prot->unhash; + psock->saved_destroy = prot->destroy; psock->saved_close = prot->close; psock->saved_write_space = sk->sk_write_space;
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index 6351b6af7aca..d846ed9c5855 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c@@ -1506,6 +1506,29 @@ void sock_map_unhash(struct sock *sk) } EXPORT_SYMBOL_GPL(sock_map_unhash); +void sock_map_destroy(struct sock *sk) +{ + void (*saved_destroy)(struct sock *sk); + struct sk_psock *psock; + + rcu_read_lock(); + psock = sk_psock_get(sk); + if (unlikely(!psock)) { + rcu_read_unlock(); + if (sk->sk_prot->destroy) + sk->sk_prot->destroy(sk); + return; + } + + saved_destroy = psock->saved_destroy; + sock_map_remove_links(sk, psock); + rcu_read_unlock(); + sk_psock_stop(psock, true); + sk_psock_put(sk, psock); + saved_destroy(sk); +} +EXPORT_SYMBOL_GPL(sock_map_destroy); + void sock_map_close(struct sock *sk, long timeout) { void (*saved_close)(struct sock *sk, long timeout);
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index 2c597a4e429a..25e83d35138b 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c@@ -541,6 +541,7 @@ static void tcp_bpf_rebuild_protos(struct proto prot[TCP_BPF_NUM_CFGS], struct proto *base) { prot[TCP_BPF_BASE] = *base; + prot[TCP_BPF_BASE].destroy = sock_map_destroy; prot[TCP_BPF_BASE].close = sock_map_close; prot[TCP_BPF_BASE].recvmsg = tcp_bpf_recvmsg; prot[TCP_BPF_BASE].sock_is_readable = sk_msg_is_readable;
--
2.35.1