From: Cong Wang cong.wang@bytedance.com
[ Upstream commit 1581a6c1c3291a8320b080f4411345f60229976d ]
Currently sk_psock_verdict_apply() is void, but it handles some error conditions too. Its caller is impossible to learn whether it succeeds or fails, especially sk_psock_verdict_recv().
Make it return int to indicate error cases and propagate errors to callers properly.
Fixes: ef5659280eb1 ("bpf, sockmap: Allow skipping sk_skb parser program") Signed-off-by: Cong Wang cong.wang@bytedance.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: John Fastabend john.fastabend@gmail.com Acked-by: Jakub Sitnicki jakub@cloudflare.com Link: https://lore.kernel.org/bpf/20210615021342.7416-7-xiyou.wangcong@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/skmsg.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/net/core/skmsg.c b/net/core/skmsg.c index dd22ca838754..539c83a45665 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -847,7 +847,7 @@ out: } EXPORT_SYMBOL_GPL(sk_psock_msg_verdict);
-static void sk_psock_skb_redirect(struct sk_buff *skb) +static int sk_psock_skb_redirect(struct sk_buff *skb) { struct sk_psock *psock_other; struct sock *sk_other; @@ -858,7 +858,7 @@ static void sk_psock_skb_redirect(struct sk_buff *skb) */ if (unlikely(!sk_other)) { kfree_skb(skb); - return; + return -EIO; } psock_other = sk_psock(sk_other); /* This error indicates the socket is being torn down or had another @@ -868,19 +868,20 @@ static void sk_psock_skb_redirect(struct sk_buff *skb) if (!psock_other || sock_flag(sk_other, SOCK_DEAD)) { skb_bpf_redirect_clear(skb); kfree_skb(skb); - return; + return -EIO; } spin_lock_bh(&psock_other->ingress_lock); if (!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED)) { spin_unlock_bh(&psock_other->ingress_lock); skb_bpf_redirect_clear(skb); kfree_skb(skb); - return; + return -EIO; }
skb_queue_tail(&psock_other->ingress_skb, skb); schedule_work(&psock_other->work); spin_unlock_bh(&psock_other->ingress_lock); + return 0; }
static void sk_psock_tls_verdict_apply(struct sk_buff *skb, struct sock *sk, int verdict) @@ -917,14 +918,15 @@ int sk_psock_tls_strp_read(struct sk_psock *psock, struct sk_buff *skb) } EXPORT_SYMBOL_GPL(sk_psock_tls_strp_read);
-static void sk_psock_verdict_apply(struct sk_psock *psock, - struct sk_buff *skb, int verdict) +static int sk_psock_verdict_apply(struct sk_psock *psock, struct sk_buff *skb, + int verdict) { struct sock *sk_other; - int err = -EIO; + int err = 0;
switch (verdict) { case __SK_PASS: + err = -EIO; sk_other = psock->sk; if (sock_flag(sk_other, SOCK_DEAD) || !sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) { @@ -957,13 +959,15 @@ static void sk_psock_verdict_apply(struct sk_psock *psock, } break; case __SK_REDIRECT: - sk_psock_skb_redirect(skb); + err = sk_psock_skb_redirect(skb); break; case __SK_DROP: default: out_free: kfree_skb(skb); } + + return err; }
static void sk_psock_write_space(struct sock *sk) @@ -1130,7 +1134,8 @@ static int sk_psock_verdict_recv(read_descriptor_t *desc, struct sk_buff *skb, ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb)); skb->sk = NULL; } - sk_psock_verdict_apply(psock, skb, ret); + if (sk_psock_verdict_apply(psock, skb, ret) < 0) + len = 0; out: rcu_read_unlock(); return len;