Only root must be able to create a new zram device, therefore hot_add attribute must have S_IRUSR mode, not S_IRUGO. Otherwise, anyone can create a new zram device (device initialization with the disksize attr requires root permission).
Fixes: 6566d1a32bf72 ("zram: add dynamic device add/remove functionality") Reported-by: Steven Allen <ste...@stebalien.com> Cc: <sta...@vger.kernel.org> [4.2+] Signed-off-by: Sergey Senozhatsky <sergey.senozhat...@gmail.com> --- drivers/block/zram/zram_drv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 5163c8f..ee03464 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1414,8 +1414,8 @@ static ssize_t hot_remove_store(struct class *class, } static struct class_attribute zram_control_class_attrs[] = { - __ATTR_RO(hot_add), - __ATTR_WO(hot_remove), + __ATTR(hot_add, 0400, hot_add_show, NULL), + __ATTR(hot_remove, 0200, NULL, hot_remove_store), __ATTR_NULL, }; -- 2.10.2