From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 61F5443E076 for ; Thu, 20 Aug 2026 12:21:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787228475; cv=none; b=P+0s6czJhNLJOJw52U9RNY7Prj02umWbOZo6nNDcgcwnNCPknuHV5kWLwo3Mz6/5SB8hiRnbSy97BfYBcH9wWz6PEZ6xwB3RfI/gZq5UhEwGjjZdZ5q5P/YHrJZ5TeU0cFoFZAeMcrkujLcV8ppD8MFnuVkf6BSV/n2DobLmhOM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787228475; c=relaxed/simple; bh=KzQpZScLIGIAjmvsBiyPR3hNhm0W/xMBso9h2Z49aC0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ciHxX1DMtgshxwxArd9FPTBu4kITslf4bvZXUysZW0OKGHC5Ahv2ji4bRdHRfSSGIlG8boJyKngU7L4Uuz5rjMY+8xkNWu3+UIRFlvy3PM/MT//dmsFFojGSRPWwMLnX4ZbGVDeIWJnM6Xnwbvl0U+mTCqAb3LPrRVNLMng6+60= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=x0SXNnes; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="x0SXNnes" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E55F1F000E9; Thu, 20 Aug 2026 12:21:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787228474; bh=79UrSvjUu30ipOJbFRGGGpKjoqk+Gh0FUlxAdtpX/s4=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=x0SXNnes0k0iGyKrDKMI1APj8kKtlVPYHKWu41u93KJ/2aFRlotV2S2tLGohIbNax d1snCpFSJNXiTkLTZVY1/tDAA7m4JAaRMcBsySqWLNbGi2if1x1Po5Zd6aHJHJd8HF 7AKTG3PtCfvdTLyYDvFH9GBsrp0eDVKcIi2ucS5w= Date: Thu, 20 Aug 2026 14:18:53 +0200 From: Greg KH To: Matthias Merz Cc: stable@vger.kernel.org, Dong Chenchen , Steffen Klassert Subject: Re: [6.12.y] Please backport 8045c0df98d4 ("xfrm: Fix dev use-after-free in xfrm async resumption") Message-ID: <2026082030-google-authentic-ad63@gregkh> References: Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Aug 07, 2026 at 04:21:55PM +0200, Matthias Merz wrote: > Hello, > > Please apply upstream commit 8045c0df98d4 ("xfrm: Fix dev use-after-free > in xfrm async resumption") also to 6.12.y. Stable 7.1.5 contains this in > 63a300151999. > > It fixes 1c428b038400 ("xfrm: hold dev ref until after transport_finish > NF_HOOK"), which is present in 6.12.y since 6.12.94. On our IPsec > gateways using xfrm interfaces this issue underflows the interface > refcount and hangs unregister_netdevice() on tunnel teardown, rekey or > system shutdown: > > unregister_netdevice: waiting for xfrm- to become free. Usage count = -381 > > This leads to a complete drop of our VPN links after some hours, and > stalls the reboot for a couple of minutes waiting for devices to become > free (I remember waiting 10-15 minutes for the shutdown when remote > rebooting a gateway without physical access) > > known affected: 6.12.96 and 6.12.96, known unaffected 6.12.90 > Fixed in 7.1.5 via 63a300151999. > > Maybe you could also consider having a look at the other longterm > releases, but I have no insight where it might apply. Please provide a working version of the backport for 6.12.y and 6.18.y and we will be glad to apply it as it does not apply cleanly as-is. thanks, greg k-h