HID: u2fzero: ignore incomplete packets without data

stable inclusion
from stable-5.10.71
commit a7f4c633ae120562e91a0891101ed44eaa6c6d1e
bugzilla: 182981 https://gitee.com/openeuler/kernel/issues/I4I3KD

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a7f4c633ae120562e91a0891101ed44eaa6c6d1e

--------------------------------

commit 22d65765 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: 42337b9d("HID: add driver for U2F Zero built-in LED and RNG")
Signed-off-by: NAndrej Shadura <andrew.shadura@collabora.co.uk>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

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 */