Re: [PATCH][next] staging: gpib: fix unset padding field copy back to userspace

[Dan Carpenter]

On Mon, Jun 23, 2025 at 11:09:58PM +0100, Colin Ian King wrote:
> The introduction of a padding field in the gpib_board_info_ioctl is
> showing up as initialized data on the stack frame being copyied back
> to userspace in function board_info_ioctl. The simplest fix is to
> initialize the entire struct to zero to ensure all unassigned padding
> fields are zero'd before being copied back to userspace.
> 
> Fixes: b8394732ff0c ("staging: gpib: Add bit and byte padding to ioctl structs")
> Signed-off-by: Colin Ian King <colin.i.king@xxxxxxxxx>
> ---

The fix is good, but the bug has been there since the driver was
introduced, it's only just now that the static checkers have started
catching it.  Oddly/sadly Smatch doesn't catch this one.  I'll have to
investigate.

Fixes: 9dde4559e939 ("staging: gpib: Add GPIB common core driver")

regards,
dan carpenter