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 271CB23099F; Mon, 10 Mar 2025 17:11:29 +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=1741626692; cv=none; b=bnA5PAwQKVhj41N8WfeFGZRCy17gcfcQxhH0lkMHuJyXW3mNlIvilI5mqdK28jRZh7PIZBIVIYZCv3qQjdH+LSf5/y/t4WODu8SzND9iwZlesqndIJ/s4TMBBOzFpQDkjuTgBwnr2SuG/avogS/i9oKq2VeEAOEc0SqRtlb2YNc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741626692; c=relaxed/simple; bh=9TTnEQPkzr4juZjjYYfiu3LYq+87EM8AwhJ+6HfQ3ds=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FjJlN8lQmMUeQgP5i5jtIlQW9TlmRwLE3zKpw/xNJW2obNBBvdJ4zTfHvzTYcrPYO6yz77l5+XocJLtqVM8TPvmw7iXOTLWF9MY+DMSWS+plcOihXjToyY2awjc4Hs27Fzfdrr6G81tOSIS8LFzzQR7PkQDNiGJtdYA3wbpqCM0= 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=q3r5zqLZ; 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="q3r5zqLZ" 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=Lv1yCpSVQyMIiwfaIWG832e3Gp7/oH0tazXadlyAtc4=; b=q3r5zqLZDaREtVev5Q07XWpqcB OpggNXiz3GYKrz5rChcUe9tUlfgoLE2i97b4mU3bFSlFyhueW2gY9HVz9ui0LlikwLtptQn6AEtHH SX6Xlj7bE0VezkkhqkIOse6wq+Ii4jji1AOsdRpPJcQxiA5X37P9KMuKpj0l32Aje0I/iCaTvJ16d zfTb3wQ6gH687orqT6cum5wShFpBZa3CjsW4lGc6aMTzjedIYfma+32/c3PNvAKd+qvU75wOIvp51 2Ig9ZqrPgcwc7SvZFbyVxIlMS4lO0zclz/Y2Kl7m/rVVIEy5kHJJ61I4xtZ2xNjxuc0mQPJYo10k9 oSmRdV6Q==; Received: from willy by casper.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1trgew-00000008LUs-428i; Mon, 10 Mar 2025 17:11:24 +0000 Date: Mon, 10 Mar 2025 17:11:22 +0000 From: Matthew Wilcox To: Yuan Tan Cc: axboe@kernel.dk, syzbot+f2aaf773187f5cae54f3@syzkaller.appspotmail.com, linux-block@vger.kernel.org, akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, falcon@tinylab.org Subject: Re: [PATCH] block: add lock for safe nrpages access in invalidate_bdev() Message-ID: References: <67ceb38a.050a0220.e1a89.04b1.GAE@google.com> <20250310165400.3166618-1-tanyuan@tinylab.org> 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: <20250310165400.3166618-1-tanyuan@tinylab.org> On Mon, Mar 10, 2025 at 09:54:00AM -0700, Yuan Tan wrote: > Syzbot reported a data-race in __filemap_add_folio / invalidate_bdev[1] > due to concurrent access to mapping->nrpages. > Adds a lock around the access to nrpages. Did you even read my analysis? This is a grossly inappropriate fix. NAK.