Commit ee7f3666 authored Dec 08, 2021 by Steven Rostedt (VMware)

tracefs: Have new files inherit the ownership of their parent

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.

Link: https://lkml.kernel.org/r/20211208075720.4855d180@gandalf.local.home



Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Yabin Cui <yabinc@google.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: stable@vger.kernel.org
Fixes: 4282d606 ("tracefs: Add new tracefs file system")
Reported-by: Kalesh Singh <kaleshsingh@google.com>
Reported: https://lore.kernel.org/all/CAC_TJve8MMAv+H_NdLSJXZUSoxOEq2zB_pVaJ9p=7H6Bu3X76g@mail.gmail.com/


Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

parent 0fcfb00b

fs/tracefs/inode.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -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);