From: Johannes Berg johannes.berg@intel.com
stable inclusion from stable-v5.10.148 commit b0e5c5deb7880be5b8a459d584e13e1f9879d307 category: bugfix bugzilla: 187803 CVE: CVE-2022-42721
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit bcca852027e5878aec911a347407ecc88d6fff7f 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: Sönke Huster shuster@seemoo.tu-darmstadt.de Tested-by: Sönke Huster shuster@seemoo.tu-darmstadt.de Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning") Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Baisong Zhong zhongbaisong@huawei.com Reviewed-by: Liu Jian liujian56@huawei.com Reviewed-by: Xiu Jianfeng xiujianfeng@huawei.com Reviewed-by: Yue Haibing yuehaibing@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- net/wireless/scan.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/net/wireless/scan.c b/net/wireless/scan.c index f8bf86898b51..fe65ad969e80 100644 --- a/net/wireless/scan.c +++ b/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;