[net-next PATCH 3/9] bpf: sockmap add missing rcu_read_(un)lock in smap_data_ready
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STALE3343d
From: John Fastabend <john.fastabend@gmail.com>
Date: 2017-08-28 14:10:59
Subsystem:
bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
References to psock must be done inside RCU critical section.
Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
kernel/bpf/sockmap.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index a6882e5..266011c8 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c@@ -227,11 +227,14 @@ static void smap_data_ready(struct sock *sk) { struct smap_psock *psock; - write_lock_bh(&sk->sk_callback_lock); + rcu_read_lock(); psock = smap_psock_sk(sk); - if (likely(psock)) + if (likely(psock)) { + write_lock_bh(&sk->sk_callback_lock); strp_data_ready(&psock->strp); - write_unlock_bh(&sk->sk_callback_lock); + write_unlock_bh(&sk->sk_callback_lock); + } + rcu_read_unlock(); } static void smap_tx_work(struct work_struct *w)