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 443FB1170D for ; Wed, 13 Mar 2024 05:25:50 +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=1710307552; cv=none; b=gNhXzj0FTqwlomxFJudzmyc+aerItLWk9LiKmL98REobhqvQHRoDUizUiXKfAxAvk41ERGZXFsRz4JVsampU2qKMeWbhtzP9yh7fsMp9iD1ZKGq5CGIgumFx1ecv8UEx6+JHjM/IWaZh6wyCOr0xgPdW2xbPxsWu0bTe30rmwzQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710307552; c=relaxed/simple; bh=U082R9f8QHQikkj8wyoDNjs8Q6Vy8eSEziBlE2TaBhQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AG8lfJgC9uoGA9Jto0he3JNdBXebbcm+ICrHfPaalgp+4LXahJEFvBVdyctLWUHlRJgAniq4+oDhx7O+Es9tAqzNZTGovU+Zkzc7SiMWfUfPHDTYtLW4vzVwXqp7tUJu+oY3ZIF1t/VxsrZhQv1InPDjyokNVgPUZc4tRKJfR6U= 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=P+S77Cbv; 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="P+S77Cbv" Date: Tue, 12 Mar 2024 22:25:42 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1710307548; 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: in-reply-to:in-reply-to:references:references; bh=NomWHFCSkpM8sEFTgc7adym5XzSbOJbpoSf/LX/csZo=; b=P+S77Cbvb0JhiNYlZXDUJUSYMP3TsgkpGiEpqktrF95FzZmXHWLhLANGdbwC9wncQg736t FM/sbsxwdCfaaDvZj4GqpFf1tbp4nbZOcYBsvErat+rKvrpliwqeLHoEqccyiu94HH0VgU EOrbbdDhO8z4QCMVfnJG8r2iFLwHf2w= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: cheung wall Cc: Marc Zyngier , Catalin Marinas , Will Deacon , James Morse , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: WARNING in kvm_age_gfn Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@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: X-Migadu-Flow: FLOW_OUT Hi, On Wed, Mar 13, 2024 at 01:02:10PM +0800, cheung wall wrote: > Hello, > > when using Syzkaller to fuzz the latest Linux Kernel arm64 version, > the following crash First, thank you. Glad to see folks are fuzzing KVM/arm64 now. > was triggered on: > > HEAD commit: 0dd3ee31125508cd67f7e7172247f05b7fd1753a (tag: v6.7) In order for these sorts of bug reports to be actionable, they really need to be against a close-to-upstream tree. 6.8 is out now, and 6.9-rc1 is right around the corner. Having said that, I think there might be an issue or two with your bot because... > git tree: upstream > > console output: https://pastebin.com/raw/3NCyqPUn > > kernel config: https://pastebin.com/raw/mXEg4abU > > C reproducer: https://pastebin.com/raw/N0gEqk5x This reproducer doesn't work on upstream (tested kvmarm-6.9 tag), and > WARNING: CPU: 0 PID: 711 at arch/arm64/kvm/mmu.c:1592 > kvm_age_gfn+0x64/0xdc > data/embfuzz/emblinux/linux-4a61839152cc3e9e00ac059d73a28d148d622b30/arch/arm64/kvm/mmu.c:1592 The SHA1 in this path is suspiciously the same as 6.1.61. Are you certain the bot is working on the correct tree? Nevertheless, I think the WARN and associated bug were addressed in commit df6556adf27b ("KVM: arm64: Correctly handle page aging notifiers for unaligned memslot"). Last thing -- I'm guessing your syzkaller runs will dredge up quite a bit of low-hanging bugs given how little exposure this code has had. Could you please aggregate the first batch of reports and send as a single series of email? Makes it much easier to keep track of. -- Thanks, Oliver