From: Andrej Shadura Date: Thu, 16 Sep 2021 16:33:11 +0000 (+0100) Subject: HID: u2fzero: ignore incomplete packets without data X-Git-Tag: accepted/tizen/unified/20230118.172025~6270^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=22d65765f211cc83186fd8b87521159f354c0da9;p=platform%2Fkernel%2Flinux-rpi.git HID: u2fzero: ignore incomplete packets without data 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 Signed-off-by: Jiri Kosina --- diff --git a/drivers/hid/hid-u2fzero.c b/drivers/hid/hid-u2fzero.c index 95e0807..d70cd3d 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; /* only take the minimum amount of data it is safe to take */