From 42ea11a81ac853c3e870c70d61ab435d0b09b851 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 28 Sep 2022 21:56:15 +0200 Subject: wifi: cfg80211: fix u8 overflow in cfg80211_update_notlisted_nontrans() commit aebe9f4639b13a1f4e9a6b42cdd2e38c617b442d upstream. 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: Soenke Huster Tested-by: Soenke Huster Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning") Reviewed-by: Kees Cook Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/wireless/scan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 0134e5d5c81a4..f59bfc09ca60f 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -2279,7 +2279,7 @@ 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); -- cgit