wifi: cfg80211: avoid nontransmitted BSS list corruption

stable inclusion
from stable-v5.10.148
commit b0e5c5deb7880be5b8a459d584e13e1f9879d307
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5VM77
CVE: CVE-2022-42721

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b0e5c5deb7880be5b8a459d584e13e1f9879d307

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

commit bcca8520 upstream.

If a non-transmitted BSS shares enough information (both
SSID and BSSID!) with another non-transmitted BSS of a
different AP, then we can find and update it, and then
try to add it to the non-transmitted BSS list. We do a
search for it on the transmitted BSS, but if it's not
there (but belongs to another transmitted BSS), the list
gets corrupted.

Since this is an erroneous situation, simply fail the
list insertion in this case and free the non-transmitted
BSS.

This fixes CVE-2022-42721.
Reported-by: NSönke Huster <shuster@seemoo.tu-darmstadt.de>
Tested-by: NSönke Huster <shuster@seemoo.tu-darmstadt.de>
Fixes: 0b8fb823 ("cfg80211: Parsing of Multiple BSSID information in scanning")
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NBaisong Zhong <zhongbaisong@huawei.com>
Reviewed-by: NLiu Jian <liujian56@huawei.com>
Reviewed-by: NXiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: NYue Haibing <yuehaibing@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

net/wireless/scan.c

@@ -423,6 +423,15 @@ cfg80211_add_nontrans_list(struct cfg80211_bss *trans_bss,
 
 	rcu_read_unlock();
 
+	/*
+	 * This is a bit weird - it's not on the list, but already on another
+	 * one! The only way that could happen is if there's some BSSID/SSID
+	 * shared by multiple APs in their multi-BSSID profiles, potentially
+	 * with hidden SSID mixed in ... ignore it.
+	 */
+	if (!list_empty(&nontrans_bss->nontrans_list))
+		return -EINVAL;
+
 	/* add to the list */
 	list_add_tail(&nontrans_bss->nontrans_list, &trans_bss->nontrans_list);
 	return 0;