wifi: cfg80211: fix u8 overflow in cfg80211_update_notlisted_nontrans()

stable inclusion
from stable-v5.10.148
commit a6408e0b694c1bdd8ae7dd0464a86b98518145ec
category: bugfix
bugzilla: 187813, https://gitee.com/src-openeuler/kernel/issues/I5VM7L
CVE: CVE-2022-41674

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a6408e0b694c1bdd8ae7dd0464a86b98518145ec

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

In the copy code of the elements, we do the following calculation
to reach the end of the MBSSID element:

	/* copy the IEs after MBSSID */
	cpy_len = mbssid[1] + 2;

This looks fine, however, cpy_len is a u8, the same as mbssid[1],
so the addition of two can overflow. In this case the subsequent
memcpy() will overflow the allocated buffer, since it copies 256
bytes too much due to the way the allocation and memcpy() sizes
are calculated.

Fix this by using size_t for the cpy_len variable.

This fixes CVE-2022-41674.
Reported-by: NSoenke Huster <shuster@seemoo.tu-darmstadt.de>
Tested-by: NSoenke Huster <shuster@seemoo.tu-darmstadt.de>
Fixes: 0b8fb823 ("cfg80211: Parsing of Multiple BSSID information in scanning")
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDong Chenchen <dongchenchen2@huawei.com>
Reviewed-by: NLiu Jian <liujian56@huawei.com>
Reviewed-by: NYue Haibing <yuehaibing@huawei.com>
Reviewed-by: NXiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

net/wireless/scan.c

@@ -2238,7 +2238,7 @@ cfg80211_update_notlisted_nontrans(struct wiphy *wiphy,
 	size_t new_ie_len;
 	struct cfg80211_bss_ies *new_ies;
 	const struct cfg80211_bss_ies *old;
-	u8 cpy_len;
+	size_t cpy_len;
 
 	lockdep_assert_held(&wiphy_to_rdev(wiphy)->bss_lock);