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authorJohannes Berg <johannes.berg@intel.com>2022-10-01 00:01:44 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-10-15 08:02:58 +0200
commit377cb1ce85878c197904ca8383e6b41886e3994d (patch)
treeedc78a627f35a86d80681a5dc1df3e69da7c5a05
parente97a5d7091e6d2df05f8378a518a9bbf81688b77 (diff)
wifi: cfg80211: avoid nontransmitted BSS list corruption
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>
-rw-r--r--net/wireless/scan.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 56a876b15598..a12c30ad9e5a 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;