[ Upstream commit 5fa2ca7c4a3fc176f31b495e1a704862d8188b53 ]
The tcp_bpf_wait_data() routine needs to check timeo != 0 before calling sk_wait_event() otherwise we may see unexpected stalls on receiver.
Arika did all the leg work here I just formatted, posted and ran a few tests.
Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Reported-by: Arika Chen eaglesora@gmail.com Suggested-by: Arika Chen eaglesora@gmail.com Signed-off-by: John Fastabend john.fastabend@gmail.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/tcp_bpf.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 4a619c85daed..3d1e15401384 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -27,7 +27,10 @@ static int tcp_bpf_wait_data(struct sock *sk, struct sk_psock *psock, int flags, long timeo, int *err) { DEFINE_WAIT_FUNC(wait, woken_wake_function); - int ret; + int ret = 0; + + if (!timeo) + return ret;
add_wait_queue(sk_sleep(sk), &wait); sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);