lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Sun, 26 Oct 2014 17:47:06 -0700
From:	Eric Dumazet <>
To:	Nikolay Aleksandrov <>
Cc:	Florian Westphal <>,
	Stephen Hemminger <>,
Subject: Re: Fw: [Bug 86851] New: Reproducible panic on heavy UDP traffic

On Mon, 2014-10-27 at 00:28 +0100, Nikolay Aleksandrov wrote:

> Thanks for CCing me.
> I'll dig in the code tomorrow but my first thought when I saw this was
> could it be possible that we have a race condition between
> ip_frag_queue() and inet_frag_evict(), more precisely between the
> ipq_kill() calls from ip_frag_queue and inet_frag_evict since the frag
> could be found before we have entered the evictor which then can add it to
> its expire list but the ipq_kill() from ip_frag_queue() can do a list_del
> after we release the chain lock in the evictor so we may end up like this ?

Yes, either we use hlist_del_init() but loose poison aid, or test if
frag was evicted :

Not sure about refcount.

diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index 9eb89f3f0ee4..894ec30c5896 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -285,7 +285,8 @@ static inline void fq_unlink(struct inet_frag_queue *fq, struct inet_frags *f)
 	struct inet_frag_bucket *hb;
 	hb = get_frag_bucket_locked(fq, f);
-	hlist_del(&fq->list);
+	if (!(fq->flags & INET_FRAG_EVICTED))
+		hlist_del(&fq->list);

To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists