Commit d8bf8c92 authored Mar 12, 2015 by Vivien Didelot Committed by Greg Kroah-Hartman Mar 25, 2015

sysfs: Only accept read/write permissions for file attributes

For sysfs file attributes, only read and write permissions make sense.
Mask provided attribute permissions accordingly and send a warning
to the console if invalid permission bits are set.

This patch is originally from Guenter [1] and includes the fixup
explained in the thread, that is printing permissions in octal format
and limiting the scope of attributes to SYSFS_PREALLOC | 0664.

[1] https://lkml.org/lkml/2015/1/19/599



Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent da4759c7

fs/sysfs/group.c

+6 −0

Original line number	Original line	Diff line number	Diff line
	@@ -55,6 +55,12 @@ static int create_files(struct kernfs_node parent, struct kobject kobj,
	if (!mode)		if (!mode)
	continue;		continue;
	}		}

			WARN(mode & ~(SYSFS_PREALLOC \| 0664),
			"Attribute %s: Invalid permissions 0%o\n",
			(*attr)->name, mode);

			mode &= SYSFS_PREALLOC \| 0664;
	error = sysfs_add_file_mode_ns(parent, *attr, false,		error = sysfs_add_file_mode_ns(parent, *attr, false,
	mode, NULL);		mode, NULL);
	if (unlikely(error))		if (unlikely(error))