From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-182.mta1.migadu.com (out-182.mta1.migadu.com [95.215.58.182]) (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 57C3317A303 for ; Sat, 30 May 2026 05:00:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780117227; cv=none; b=hWDP4805tRMkF3GsqYHIXspFaVgA0JFxS4NhIDh3SmhlW6rfyg4Y2EPm1F5kiYyNwo7nzygU01b+szchNMLQwk48YonALeUgb2Ug1REbAe3margULWqXyVeyshOJA1zm/G29BWnr2usgUQMtJkd9APwOD2lp5g1YeZP2AyLVXBg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780117227; c=relaxed/simple; bh=bs36QcS8fMJrTk5szSTZJ3tc+6ZBIoy+8y5ivAc9eQ4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=iEt1AXV0Slb52Wx0IDJHTS/msYoasz0M2O/oq5pShD/kH++i3QiyGd6Wo4h6pRcSTbt/LtsgV9WepnuFy2BRs1C8Xo6AJQ5Qg6PxtoJ1c9zyeMZXJkTFeHkGU0AymrWpnakE71YafuyhOl2H6oXxyETy0BtUn3JteuuenGitFXI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=OvVKDCBf; arc=none smtp.client-ip=95.215.58.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="OvVKDCBf" Message-ID: <63b950ee-a137-4c65-bace-915f813d5459@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1780117224; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9NUUjgvmzZYYcCbigWCzkHqVs/Edq5TVDYxrE/lSUPM=; b=OvVKDCBfL7CPUMEaeSBePNWMWxskvQmhm3K0xBfI0cKDMUgB6uuGzEVdWsym6+HQW8EhK+ caP9tqBKwZEZxmS+HZeFURu/e9jadd0hpfxuKUNTFtk5e2qcVNYh0udplMt3zn5ePhed5v 9pZXYQrw+rmqxPQhVy44CEBQj/MGxXc= Date: Sat, 30 May 2026 13:00:13 +0800 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH net v2] ipv6: anycast: insert aca into global hash under idev->lock To: Jakub Kicinski Cc: netdev@vger.kernel.org, syzbot+819eb928d120d2bdad0e@syzkaller.appspotmail.com, Kuniyuki Iwashima , David Ahern , Ido Schimmel , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , linux-kernel@vger.kernel.org References: <20260529152219.235475-1-jiayuan.chen@linux.dev> <20260529135116.183e083e@kernel.org> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Jiayuan Chen In-Reply-To: <20260529135116.183e083e@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 5/30/26 4:51 AM, Jakub Kicinski wrote: > On Fri, 29 May 2026 23:22:18 +0800 Jiayuan Chen wrote: >> syzbot reported a splat [1]: a slab-use-after-free in >> ipv6_chk_acast_addr(), which walks the global inet6_acaddr_lst[] hash >> under RCU and dereferences a struct ifacaddr6 that has already been >> freed while still linked in the hash, so a later reader walks into a >> dangling node. > Please do not violate the 24h repost grace period on netdev. > We are tracking the violations now, if you keep doing this > there will be consequences.. Oops, sorry about that. I slept on it and somehow got confused about the timing. I will make sure to wait for the full 24 hours next time.