From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21525C83F13 for ; Mon, 28 Aug 2023 10:22:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230178AbjH1KWO (ORCPT ); Mon, 28 Aug 2023 06:22:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230518AbjH1KVu (ORCPT ); Mon, 28 Aug 2023 06:21:50 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB98D136 for ; Mon, 28 Aug 2023 03:21:30 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 34D3A638EE for ; Mon, 28 Aug 2023 10:21:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3AA8DC433C8; Mon, 28 Aug 2023 10:21:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693218079; bh=91qeNnNHuDWmx+AxHkIBov4XrfVHp98ZP97pA9wjO/I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DlPV2dtlSwloh+X1CZv+pZxv2M64FOYL32SmV8zHdyWhmlyAiBaY+h0+KavIXXlfu D1fa+tUv3n2ML0MDlXCbd/VsAJ69WGn9+N962vSgtyKTLfPEvDG8BYzWX0M9pfKd99 63f1PC4zu04gYv9a4vkllOez9+HmAAoA1FMGS+eM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ryusuke Konishi , syzbot+0ad741797f4565e7e2d2@syzkaller.appspotmail.com, Andrew Morton Subject: [PATCH 6.4 088/129] nilfs2: fix general protection fault in nilfs_lookup_dirty_data_buffers() Date: Mon, 28 Aug 2023 12:12:47 +0200 Message-ID: <20230828101200.282396340@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101157.383363777@linuxfoundation.org> References: <20230828101157.383363777@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ryusuke Konishi commit f83913f8c5b882a312e72b7669762f8a5c9385e4 upstream. A syzbot stress test reported that create_empty_buffers() called from nilfs_lookup_dirty_data_buffers() can cause a general protection fault. Analysis using its reproducer revealed that the back reference "mapping" from a page/folio has been changed to NULL after dirty page/folio gang lookup in nilfs_lookup_dirty_data_buffers(). Fix this issue by excluding pages/folios from being collected if, after acquiring a lock on each page/folio, its back reference "mapping" differs from the pointer to the address space struct that held the page/folio. Link: https://lkml.kernel.org/r/20230805132038.6435-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Reported-by: syzbot+0ad741797f4565e7e2d2@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/0000000000002930a705fc32b231@google.com Tested-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- fs/nilfs2/segment.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -725,6 +725,11 @@ static size_t nilfs_lookup_dirty_data_bu struct folio *folio = fbatch.folios[i]; folio_lock(folio); + if (unlikely(folio->mapping != mapping)) { + /* Exclude folios removed from the address space */ + folio_unlock(folio); + continue; + } head = folio_buffers(folio); if (!head) { create_empty_buffers(&folio->page, i_blocksize(inode), 0);