Re: [PATCH v2] kernel: sysctl: ignore out-of-range taint bits introduced via kernel.tainted

From: Luis Chamberlain
Date: Tue May 12 2020 - 20:40:00 EST


On Tue, May 12, 2020 at 06:39:46PM -0400, Rafael Aquini wrote:
> Users with SYS_ADMIN capability can add arbitrary taint flags
> to the running kernel by writing to /proc/sys/kernel/tainted
> or issuing the command 'sysctl -w kernel.tainted=...'.
> These interface, however, are open for any integer value
> and this might an invalid set of flags being committed to
> the tainted_mask bitset.
>
> This patch introduces a simple way for proc_taint() to ignore
> any eventual invalid bit coming from the user input before
> committing those bits to the kernel tainted_mask.
>
> Signed-off-by: Rafael Aquini <aquini@xxxxxxxxxx>

Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>

Luis