linux-kernel - [PATCH v2] tracefs: Have new files inherit the ownership of their parent

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Date:   Wed, 8 Dec 2021 07:57:20 -0500
From:   Steven Rostedt <rostedt@...dmis.org>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     Kalesh Singh <kaleshsingh@...gle.com>,
        Kees Cook <keescook@...omium.org>,
        Ingo Molnar <mingo@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        linux-fsdevel@...r.kernel.org, Al Viro <viro@...iv.linux.org.uk>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Yabin Cui <yabinc@...gle.com>,
        Christian Brauner <christian.brauner@...ntu.com>
Subject: [PATCH v2] tracefs: Have new files inherit the ownership of their
 parent

From: "Steven Rostedt (VMware)" <rostedt@...dmis.org>

If directories in tracefs have their ownership changed, then any new files
and directories that are created under those directories should inherit
the ownership of the director they are created in.

Cc: Kees Cook <keescook@...omium.org>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Al Viro <viro@...iv.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Yabin Cui <yabinc@...gle.com>
Cc: Christian Brauner <christian.brauner@...ntu.com>
Cc: stable@...r.kernel.org
Fixes: 4282d60689d4f ("tracefs: Add new tracefs file system")
Reported-by: Kalesh Singh <kaleshsingh@...gle.com>
Reported: https://lore.kernel.org/all/CAC_TJve8MMAv+H_NdLSJXZUSoxOEq2zB_pVaJ9p=7H6Bu3X76g@mail.gmail.com/
Signed-off-by: Steven Rostedt (VMware) <rostedt@...dmis.org>
---
Changes since v1: https://lkml.kernel.org/r/20211207144828.3d356e26@gandalf.local.home
  - Use d_inode() helper function as suggested by Christian.

 fs/tracefs/inode.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index 925a621b432e..06cf0534cc60 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -414,6 +414,8 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode,
 	inode->i_mode = mode;
 	inode->i_fop = fops ? fops : &tracefs_file_operations;
 	inode->i_private = data;
+	inode->i_uid = d_inode(dentry->d_parent)->i_uid;
+	inode->i_gid = d_inode(dentry->d_parent)->i_gid;
 	d_instantiate(dentry, inode);
 	fsnotify_create(dentry->d_parent->d_inode, dentry);
 	return end_creating(dentry);
@@ -436,6 +438,8 @@ static struct dentry *__create_dir(const char *name, struct dentry *parent,
 	inode->i_mode = S_IFDIR | S_IRWXU | S_IRUSR| S_IRGRP | S_IXUSR | S_IXGRP;
 	inode->i_op = ops;
 	inode->i_fop = &simple_dir_operations;
+	inode->i_uid = d_inode(dentry->d_parent)->i_uid;
+	inode->i_gid = d_inode(dentry->d_parent)->i_gid;
 
 	/* directory inodes start off with i_nlink == 2 (for "." entry) */
 	inc_nlink(inode);
-- 
2.31.1