From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 E586D8F40; Mon, 9 Jun 2025 20:48:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749502135; cv=none; b=hQBJHvjXNl1HY/zaSlz7vNO7BfZHdTdKfdrKeg7y99lWAMw63zKxfb8y1fb1E8tlPHh6A85i/U+KJmx5zMLvJsiMesjLBQQhtYccoxKUaJoDLCwxv3pIiLB5y73e1WPqz2onZyRC4WzCz7Nx7Qxt9WZc4QmIVXwfdLEc0YbiISM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749502135; c=relaxed/simple; bh=BbylnXMDljaBHyc9rSMVIJONPpTA1nJHbzOSVi4nMPA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=s/whtjzVCBokQVNgpiq2IUYZfeK12EyPy4I706leU57oqbj6aS+w32bgDAlEKHAyQ2+S8+0Dl1BQpMTWdqSRHQnsEzgCEEZD/ID4yzgzhYOBX8QLOut1rb6pd4i9Uo8Wf4+Z5AOw4yZuMYW0yPtrtfDD5Dyf14SiFVwau6Mi3P0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=T5Pt7E/v; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="T5Pt7E/v" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=oJ0XlIsk5G25C5qCHOroSyNzywC12UcQLttP2Js+zCc=; b=T5Pt7E/vG5+N3/LLA/JnM8K4EY mp5tZW7D4q0WBssO3i5R3PIK/qRbn5zKfmumaSPz85IicFCYA7f+XiL40CE/ovVbwBzOj/ALf8TFh MG7IoZz5AZRNNPkq2KtwncNmAKsD/Ky79gwagUlRS/BP1mOrmupg6xzNaYih6u77fhdM/o0fFr/AZ 9a/IOg5p3e/TJl7E2uhGpphrxapCUhb01Kd8SP8ScyuQjyB1LhMDAwDf+z+1nikwhxVpMsUckepAV dky8rUzl6P8TNz8qPzgQSqho3fniszDxP/y5pX5bZk/iFgCDRn3uOODfuKBxihWFgM/tcM5dxkuyy +xVpkzsA==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1uOjQH-00000008doG-3sQP; Mon, 09 Jun 2025 20:48:49 +0000 Date: Mon, 9 Jun 2025 21:48:49 +0100 From: Matthew Wilcox To: Jan Kara Cc: Xianying Wang , viro@zeniv.linux.org.uk, brauner@kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [BUG] WARNING in bdev_getblk Message-ID: References: Precedence: bulk X-Mailing-List: linux-fsdevel@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 Mon, Jun 09, 2025 at 03:54:01PM +0200, Jan Kara wrote: > Hi! > > On Mon 09-06-25 16:39:15, Xianying Wang wrote: > > I encountered a kernel WARNING in the function bdev_getblk() when > > fuzzing the Linux 6.12 kernel using Syzkaller. The crash occurs during > > a block buffer allocation path, where __alloc_pages_noprof() fails > > under memory pressure, and triggers a WARNING due to an internal > > allocation failure. > > Ah, this is a warning about GFP_NOFAIL allocation from direct reclaim: It's the same discussion we had at LSFMM. It seems like we have a lot of "modified syzkaller" people trying this kind of thing.