Re: [PATCH] autofs: use flexible array in ioctl structure

From: Kees Cook
Date: Tue May 23 2023 - 13:06:23 EST


On Tue, 23 May 2023 10:19:35 +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> Commit df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3") introduced a warning
> for the autofs_dev_ioctl structure:
>
> In function 'check_name',
> inlined from 'validate_dev_ioctl' at fs/autofs/dev-ioctl.c:131:9,
> inlined from '_autofs_dev_ioctl' at fs/autofs/dev-ioctl.c:624:8:
> fs/autofs/dev-ioctl.c:33:14: error: 'strchr' reading 1 or more bytes from a region of size 0 [-Werror=stringop-overread]
> 33 | if (!strchr(name, '/'))
> | ^~~~~~~~~~~~~~~~~
> In file included from include/linux/auto_dev-ioctl.h:10,
> from fs/autofs/autofs_i.h:10,
> from fs/autofs/dev-ioctl.c:14:
> include/uapi/linux/auto_dev-ioctl.h: In function '_autofs_dev_ioctl':
> include/uapi/linux/auto_dev-ioctl.h:112:14: note: source object 'path' of size 0
> 112 | char path[0];
> | ^~~~
>
> [...]

Applied to for-next/hardening, thanks!

[1/1] autofs: use flexible array in ioctl structure
https://git.kernel.org/kees/c/e6d6886d469f

--
Kees Cook