From: Florian Westphal <fw@strlen.de>
To: Qingjie Xing <xqjcool@gmail.com>
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
netfilter-devel@vger.kernel.org
Subject: Re: [PATCH] netfilter: conntrack: drop expectations before freeing templates
Date: Wed, 20 Aug 2025 02:17:10 +0200 [thread overview]
Message-ID: <aKUUBsFYBYOu2xu-@strlen.de> (raw)
In-Reply-To: <20250819232417.2337655-1-xqjcool@gmail.com>
Qingjie Xing <xqjcool@gmail.com> wrote:
> With an iptables-configured TFTP helper in place, a UDP packet
> (10.65.41.36:1069 → 10.65.36.2:69, TFTP RRQ) triggered creation of an expectation.
> Later, iptables changes removed the rule’s per-rule template nf_conn.
> When the expectation’s timer expired, nf_ct_unlink_expect_report()
> ran and dereferenced the freed master, causing a crash.
Sorry, I do not see the problem.
A template should never be listed as exp->master.
Can you make a reproducer/selftest for this bug?
I worry we paper over a different bug.
next prev parent reply other threads:[~2025-08-20 0:17 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-19 18:17 [PATCH] netfilter: conntrack: drop expectations before freeing templates Qingjie Xing
2025-08-19 18:27 ` Florian Westphal
2025-08-19 23:24 ` Qingjie Xing
2025-08-20 0:17 ` Florian Westphal [this message]
2025-08-20 0:24 ` Florian Westphal
2025-08-20 18:32 ` Qingjie Xing
2025-08-21 7:18 ` Florian Westphal
2025-08-22 1:17 ` Qingjie Xing
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