openwrt/package/kernel/mac80211/patches/subsys/351-wifi-cfg80211-fix-u8-overflow-in-cfg80211_update_not.patch
Felix Fietkau f1de43d0a0 mac80211: backport security fixes
This mainly affects scanning and beacon parsing, especially with MBSSID enabled

Fixes: CVE-2022-41674
Fixes: CVE-2022-42719
Fixes: CVE-2022-42720
Fixes: CVE-2022-42721
Fixes: CVE-2022-42722
Signed-off-by: Felix Fietkau <nbd@nbd.name>
(cherry-picked from commit 26f400210d6b3780fcc0deb89b9741837df9c8b8)
2022-10-13 15:10:56 +02:00

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1.3 KiB
Diff

From: Johannes Berg <johannes.berg@intel.com>
Date: Wed, 28 Sep 2022 21:56:15 +0200
Subject: [PATCH] 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 <shuster@seemoo.tu-darmstadt.de>
Tested-by: Soenke Huster <shuster@seemoo.tu-darmstadt.de>
Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -2238,7 +2238,7 @@ cfg80211_update_notlisted_nontrans(struc
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);