| From 22d65765f211cc83186fd8b87521159f354c0da9 Mon Sep 17 00:00:00 2001 |
| From: Andrej Shadura <andrew.shadura@collabora.co.uk> |
| Date: Thu, 16 Sep 2021 17:33:11 +0100 |
| Subject: HID: u2fzero: ignore incomplete packets without data |
| |
| From: Andrej Shadura <andrew.shadura@collabora.co.uk> |
| |
| commit 22d65765f211cc83186fd8b87521159f354c0da9 upstream. |
| |
| 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@collabora.co.uk> |
| Signed-off-by: Jiri Kosina <jkosina@suse.cz> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/hid/hid-u2fzero.c | 4 +++- |
| 1 file changed, 3 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/hid/hid-u2fzero.c |
| +++ b/drivers/hid/hid-u2fzero.c |
| @@ -198,7 +198,9 @@ static int u2fzero_rng_read(struct hwrng |
| } |
| |
| 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 */ |
