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 X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39D70C433E9 for ; Mon, 1 Mar 2021 18:39:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C0F560233 for ; Mon, 1 Mar 2021 18:39:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240244AbhCASiU (ORCPT ); Mon, 1 Mar 2021 13:38:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:43176 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235375AbhCAS3I (ORCPT ); Mon, 1 Mar 2021 13:29:08 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 719386535B; Mon, 1 Mar 2021 17:45:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614620752; bh=EnBmsuJYKSpZiuhUD6hO6qDSM8ZcOC22+RqBoIHyr/w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Yz6RS4ONceO/Agy3vzq+c/n0NuNsqCCV6ud2uKc01RSHBWHs3iHPrYdVgWsrccKVR Me6xKGgNYM6gcWvRy5iGUea0APKIcwbArIADPR6/4RkFmp6XdHSuiNg/A89oOAgBZ/ euhp4ImCrbFh8gczXsT2i3Vo/e5WG/ECLCPQ3WtQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daeho Jeong , Colin Ian King , Chao Yu , Jaegeuk Kim , Sasha Levin Subject: [PATCH 5.11 236/775] f2fs: fix null page reference in redirty_blocks Date: Mon, 1 Mar 2021 17:06:44 +0100 Message-Id: <20210301161213.291220418@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161201.679371205@linuxfoundation.org> References: <20210301161201.679371205@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Daeho Jeong [ Upstream commit df0736d70c4fa6ed711ba103b61880fe72bb4777 ] By Colin's static analysis, we found out there is a null page reference under low memory situation in redirty_blocks. I've made the page finding loop stop immediately and return an error not to cause further memory pressure when we run into a failure to find a page under low memory condition. Signed-off-by: Daeho Jeong Reported-by: Colin Ian King Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE") Reviewed-by: Colin Ian King Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/file.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index f585545277d77..cd62b0d3369ab 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -4043,8 +4043,10 @@ static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len) for (i = 0; i < page_len; i++, redirty_idx++) { page = find_lock_page(mapping, redirty_idx); - if (!page) - ret = -ENOENT; + if (!page) { + ret = -ENOMEM; + break; + } set_page_dirty(page); f2fs_put_page(page, 1); f2fs_put_page(page, 0); -- 2.27.0