From nobody Mon Jun 22 14:27:25 2026 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 063DEC433EF for ; Tue, 22 Mar 2022 08:08:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229887AbiCVIKS (ORCPT ); Tue, 22 Mar 2022 04:10:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229819AbiCVIKG (ORCPT ); Tue, 22 Mar 2022 04:10:06 -0400 Received: from out203-205-221-209.mail.qq.com (out203-205-221-209.mail.qq.com [203.205.221.209]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D4352AEB for ; Tue, 22 Mar 2022 01:08:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foxmail.com; s=s201512; t=1647936509; bh=xj3turLHj1+ZCP9WjX9RjyOgZj7/g+f5TXLsbJ08Z6M=; h=From:To:Cc:Subject:Date; b=xqVD+HGcJkCFOyljoIp7AMoNMKPGUu99PpNUIOlf+DvxjAJPPrI4fduHOJFacVYVr GRuaYrjbg2nt5PsivERMq27ia9NEQ3IS16tfouF9eIDXJgAr3fXx+Bvj7l7kCGkCdw kbZMhRo0T1ELx91QaoWHBT8Fl4UppkgV+gR7LG+U= Received: from localhost.localdomain ([43.227.136.188]) by newxmesmtplogicsvrsza7.qq.com (NewEsmtp) with SMTP id 2198E433; Tue, 22 Mar 2022 16:08:25 +0800 X-QQ-mid: xmsmtpt1647936505ts0dqrfgq Message-ID: X-QQ-XMAILINFO: OQhZ3T0tjf0amHFt3Tv8ZnikjPM7gbCsdRyJBbsvvF8MDJx4K0X2JtCTAGGCU0 USVhMFfAWjMjApTDU0aOobRK8pKYK3+RP3AW3nqaJpQDuEo3v+6XHgfjIidbeMx/M4EjU5yn3OBg T1nJpiqqVxcWjX2wgfoZUT4d0K3/3Fn0ijEvxk4UYsL4gjD5JdZq/xB2vVpgTfR7qoaeyyWys8h3 GIxWb0I7I7iL6FCZfpKxoW+td9hHBy9cxxgmgapMa80vA6nSAuSyuoWnO5VwcirEQxNxDzspaFTc Wzu9tf93C7pxlsPW9gYCxOV3rtvgNjp1P/Z1Jp9cktsS/4WE1j0EyR6N3Rw8N9Vq81jRNOqDxyNW QsooJ8v+Ve1uqvfFswT+ZlDrIi/nOA5sfc5npycGs0faGzseuP8x+j8gP3C0uv/aGkcRcQ9NMqpr ONKu3/KSyHZJKOpn5hM2FDv/AHegPeJPxfb0F1BAnIlUm3Uw4Dm9R0144DjFZQ1KrF4mT2qB6+bU V1SsSXP2n6/OTq7FLHWbK2cWqLCMcB0hOxaUfTySxM4ExWp6XWT9DuIiQm8THsHfux+j3TFS/DGQ xyo5dXyXvFCp2cLOTiO9r+v4QcU2zV//beLzq6LxW3hLz5TN1tHe64Or2BTg63qLl8o/vFWw8qKM FtR1ZHdzjowCuoI5QPr/BkDrdodtZhjsET7o2lU2x9coG97wJYM8SrQZfjY6wghWAcRGx0q3IdjA s0wa1nHLCU0GWlrnKN7w1Xp8vP8Ki2+qBF7Fji2KrB91QsrGWps/NIuvvemUGFtW/qTncFAhQi/M 1QmnJlQFv4lP8HuAjJk337DjfCMwrQQw8AFYhHkM3WbbR4R/y6L4ISkyHjUKjbtmyWHKu89AO8pn j8RUABvcj64AYPpaYlnhmxhD/T1XOSZhApA9AxkzHkL9hvz+6Io18NpxRgiXT4EbP9MdGe3vxO From: xkernel.wang@foxmail.com To: xiang@kernel.org, chao@kernel.org Cc: linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org, Xiaoke Wang Subject: [PATCH] erofs: fix a potential NULL dereference of alloc_pages() Date: Tue, 22 Mar 2022 16:08:12 +0800 X-OQ-MSGID: <20220322080812.1574-1-xkernel.wang@foxmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Xiaoke Wang alloc_pages() returns the page on success or NULL if allocation fails, while set_page_private() will dereference `newpage`. So it is better to catch the memory error in case other errors happen. Signed-off-by: Xiaoke Wang --- fs/erofs/zdata.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index 11c7a1a..36a5421 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -735,11 +735,15 @@ static int z_erofs_do_read_page(struct z_erofs_decomp= ress_frontend *fe, struct page *const newpage =3D alloc_page(GFP_NOFS | __GFP_NOFAIL); =20 - set_page_private(newpage, Z_EROFS_SHORTLIVED_PAGE); - err =3D z_erofs_attach_page(clt, newpage, - Z_EROFS_PAGE_TYPE_EXCLUSIVE); - if (!err) - goto retry; + if (!newpage) { + err =3D -ENOMEM; + } else { + set_page_private(newpage, Z_EROFS_SHORTLIVED_PAGE); + err =3D z_erofs_attach_page(clt, newpage, + Z_EROFS_PAGE_TYPE_EXCLUSIVE); + if (!err) + goto retry; + } } =20 if (err) --