From 976d28bfd1f62a3f8e5370c5e7127ff5b3499359 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Thu, 17 Aug 2017 17:22:36 +0200 Subject: [PATCH] bpf: don't enable preemption twice in smap_do_verdict In smap_do_verdict(), the fall-through branch leads to call preempt_enable() twice for the SK_REDIRECT, which creates an imbalance. Only enable it for all remaining cases again. Fixes: 174a79ff9515 ("bpf: sockmap with sk redirect support") Reported-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- kernel/bpf/sockmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c index f7e5e6cf124a..39de541fbcdc 100644 --- a/kernel/bpf/sockmap.c +++ b/kernel/bpf/sockmap.c @@ -135,7 +135,8 @@ static void smap_do_verdict(struct smap_psock *psock, struct sk_buff *skb) /* Fall through and free skb otherwise */ case SK_DROP: default: - preempt_enable(); + if (rc != SK_REDIRECT) + preempt_enable(); kfree_skb(skb); } } -- 2.30.2