On 8/17/17 9:03 AM, John Fastabend wrote:
On 08/17/2017 08:22 AM, Daniel Borkmann wrote:
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 <a...@kernel.org>
Signed-off-by: Daniel Borkmann <dan...@iogearbox.net>
---
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 f7e5e6c..39de541 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);
}
}
Yep looks good, nice catch Alexei. Thanks! I'll add a selftests entry
in test_maps to catch this fall through case. Looks like we don't hit
this case during selftests at the moment.
Acked-by: John Fastabend <john.fastab...@gmail.com>
Acked-by: Alexei Starovoitov <a...@kernel.org>
