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 DACFAEB64DD for ; Sun, 16 Jul 2023 15:14:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230097AbjGPPOa (ORCPT ); Sun, 16 Jul 2023 11:14:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43470 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230116AbjGPPO2 (ORCPT ); Sun, 16 Jul 2023 11:14:28 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF06D10D9 for ; Sun, 16 Jul 2023 08:14:25 -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 5FFDC60D2D for ; Sun, 16 Jul 2023 15:14:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 450D2C433C8; Sun, 16 Jul 2023 15:14:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689520464; bh=7nlg8mWYdGa8lZ06gb2ls3XJf3To/5HIL2kTKpxZC+0=; h=Subject:To:Cc:From:Date:From; b=ck7PBZqFWN1kKgdlGDa5hNiS4rDXtD/bZaw0fmWyJfLIJ5iNjTnls62QblsGvXiE5 43C/pFDIPf02eHfHbWln/JH/OYv0Jt7tAZN5d1U3VR8UkG9sVmeEGRl+nanHjx+zc7 ul5CUJjWbNtRONOJAh1j9xomj1ru4GiPNjlkoeQ8= Subject: FAILED: patch "[PATCH] ovl: fix null pointer dereference in ovl_get_acl_rcu()" failed to apply to 6.1-stable tree To: chengzhihao1@huawei.com, amir73il@gmail.com, brauner@kernel.org, mszeredi@redhat.com, stable@vger.kernel.org Cc: From: Date: Sun, 16 Jul 2023 17:14:21 +0200 Message-ID: <2023071621-charcoal-prewashed-932b@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x f4e19e595cc2e76a8a58413eb19d3d9c51328b53 # git commit -s git send-email --to '' --in-reply-to '2023071621-charcoal-prewashed-932b@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: f4e19e595cc2 ("ovl: fix null pointer dereference in ovl_get_acl_rcu()") 6c0a8bfb84af ("ovl: implement get acl method") cac2f8b8d8b5 ("fs: rename current get acl method") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From f4e19e595cc2e76a8a58413eb19d3d9c51328b53 Mon Sep 17 00:00:00 2001 From: Zhihao Cheng Date: Tue, 16 May 2023 22:16:19 +0800 Subject: [PATCH] ovl: fix null pointer dereference in ovl_get_acl_rcu() Following process: P1 P2 path_openat link_path_walk may_lookup inode_permission(rcu) ovl_permission acl_permission_check check_acl get_cached_acl_rcu ovl_get_inode_acl realinode = ovl_inode_real(ovl_inode) drop_cache __dentry_kill(ovl_dentry) iput(ovl_inode) ovl_destroy_inode(ovl_inode) dput(oi->__upperdentry) dentry_kill(upperdentry) dentry_unlink_inode upperdentry->d_inode = NULL ovl_inode_upper upperdentry = ovl_i_dentry_upper(ovl_inode) d_inode(upperdentry) // returns NULL IS_POSIXACL(realinode) // NULL pointer dereference , will trigger an null pointer dereference at realinode: [ 205.472797] BUG: kernel NULL pointer dereference, address: 0000000000000028 [ 205.476701] CPU: 2 PID: 2713 Comm: ls Not tainted 6.3.0-12064-g2edfa098e750-dirty #1216 [ 205.478754] RIP: 0010:do_ovl_get_acl+0x5d/0x300 [ 205.489584] Call Trace: [ 205.489812] [ 205.490014] ovl_get_inode_acl+0x26/0x30 [ 205.490466] get_cached_acl_rcu+0x61/0xa0 [ 205.490908] generic_permission+0x1bf/0x4e0 [ 205.491447] ovl_permission+0x79/0x1b0 [ 205.491917] inode_permission+0x15e/0x2c0 [ 205.492425] link_path_walk+0x115/0x550 [ 205.493311] path_lookupat.isra.0+0xb2/0x200 [ 205.493803] filename_lookup+0xda/0x240 [ 205.495747] vfs_fstatat+0x7b/0xb0 Fetch a reproducer in [Link]. Use the helper ovl_i_path_realinode() to get realinode and then do non-nullptr checking. Link: https://bugzilla.kernel.org/show_bug.cgi?id=217404 Fixes: 332f606b32b6 ("ovl: enable RCU'd ->get_acl()") Cc: # v5.15 Signed-off-by: Zhihao Cheng Suggested-by: Christian Brauner Suggested-by: Amir Goldstein Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index ca56b1328a2c..e7e888dea634 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -558,20 +558,20 @@ struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, struct inode *inode, int type, bool rcu, bool noperm) { - struct inode *realinode = ovl_inode_real(inode); + struct inode *realinode; struct posix_acl *acl; struct path realpath; - if (!IS_POSIXACL(realinode)) - return NULL; - /* Careful in RCU walk mode */ - ovl_i_path_real(inode, &realpath); - if (!realpath.dentry) { + realinode = ovl_i_path_real(inode, &realpath); + if (!realinode) { WARN_ON(!rcu); return ERR_PTR(-ECHILD); } + if (!IS_POSIXACL(realinode)) + return NULL; + if (rcu) { /* * If the layer is idmapped drop out of RCU path walk