On Mon, Jul 27, 2020 at 04:16:08PM +0300, Dan Carpenter wrote:
> drivers/block/floppy.c:3132 raw_cmd_copyout() warn: check that 'cmd' doesn't
> leak information (struct has a hole after 'flags')
(Removed some Cc: recipients from the list.)
I'm not very sure, but I think this one is also a false positive.
Here Smatch is complaining about a linked list called `my_raw_cmd`
defined in raw_cmd_ioctl():
drivers/block/floppy.c:3249:
ret = raw_cmd_copyin(cmd, param, &my_raw_cmd);
In raw_cmd_copyin(), each element of the linked list is allocated by
kmalloc() then copied from user:
drivers/block/floppy.c:3180:
loop:
ptr = kmalloc(sizeof(struct floppy_raw_cmd), GFP_KERNEL);
^^^^^^^
if (!ptr)
return -ENOMEM;
*rcmd = ptr;
ret = copy_from_user(ptr, param, sizeof(*ptr));
^^^^^^^^^^^^^^
I think copy_from_user() is filling in the paddings inside `struct
floppy_raw_cmd`?
Thank you,
Peilin Ye
