On Thu, 16 Sep 2021, Andrej Shadura wrote:
> Since the actual_length calculation is performed unsigned, packets
> shorter than 7 bytes (e.g. packets without data or otherwise truncated)
> or non-received packets ("zero" bytes) can cause buffer overflow.
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=214437
> Fixes: 42337b9d4d958("HID: add driver for U2F Zero built-in LED and RNG")
> Signed-off-by: Andrej Shadura <andrew.shadura@xxxxxxxxxxxxxxx>
> ---
> drivers/hid/hid-u2fzero.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hid/hid-u2fzero.c b/drivers/hid/hid-u2fzero.c
> index 95e0807878c7..d70cd3d7f583 100644
> --- a/drivers/hid/hid-u2fzero.c
> +++ b/drivers/hid/hid-u2fzero.c
> @@ -198,7 +198,9 @@ static int u2fzero_rng_read(struct hwrng *rng, void *data,
> }
>
> ret = u2fzero_recv(dev, &req, &resp);
> - if (ret < 0)
> +
> + /* ignore errors or packets without data */
> + if (ret < offsetof(struct u2f_hid_msg, init.data))
> return 0;
>
Applied, thanks.
--
Jiri Kosina
SUSE Labs
