mac80211: bail out if cipher schemes are invalid

If any of the cipher schemes specified by the driver are invalid, bail
out and fail the registration rather than just warning.  Otherwise, we
might later crash when we try to use the invalid cipher scheme, e.g.
if the hdr_len is (significantly) less than the pn_offs + pn_len, we'd
have an out-of-bounds access in RX validation.

Fixes: 2475b1cc ("mac80211: add generic cipher scheme support")
Link: https://lore.kernel.org/r/20210408143149.38a3a13a1b19.I6b7f5790fa0958ed8049cf02ac2a535c61e9bc96@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/main.c

@@ -1141,8 +1141,11 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 	if (local->hw.wiphy->max_scan_ie_len)
 		local->hw.wiphy->max_scan_ie_len -= local->scan_ies_len;
 
-	WARN_ON(!ieee80211_cs_list_valid(local->hw.cipher_schemes,
-					 local->hw.n_cipher_schemes));
+	if (WARN_ON(!ieee80211_cs_list_valid(local->hw.cipher_schemes,
+					     local->hw.n_cipher_schemes))) {
+		result = -EINVAL;
+		goto fail_workqueue;
+	}
 
 	result = ieee80211_init_cipher_suites(local);
 	if (result < 0)