From 312ca38ddda64bac6513ec68e0ac3789b4eb44dc Mon Sep 17 00:00:00 2001 From: Jouni Malinen Date: Wed, 5 Dec 2018 12:55:54 +0200 Subject: [PATCH] cfg80211: Fix busy loop regression in ieee80211_ie_split_ric() This function was modified to support the information element extension case (WLAN_EID_EXTENSION) in a manner that would result in an infinite loop when going through set of IEs that include WLAN_EID_RIC_DATA and contain an IE that is in the after_ric array. The only place where this can currently happen is in mac80211 ieee80211_send_assoc() where ieee80211_ie_split_ric() is called with after_ric[]. This can be triggered by valid data from user space nl80211 association/connect request (i.e., requiring GENL_UNS_ADMIN_PERM). The only known application having an option to include WLAN_EID_RIC_DATA in these requests is wpa_supplicant and it had a bug that prevented this specific contents from being used (and because of that, not triggering this kernel bug in an automated test case ap_ft_ric) and now that this bug is fixed, it has a workaround to avoid this kernel issue. WLAN_EID_RIC_DATA is currently used only for testing purposes, so this does not cause significant harm for production use cases. Fixes: 2512b1b18d07 ("mac80211: extend ieee80211_ie_split to support EXTENSION") Cc: stable@vger.kernel.org Signed-off-by: Jouni Malinen Signed-off-by: Johannes Berg --- net/wireless/util.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/wireless/util.c b/net/wireless/util.c index ef14d80ca03e..d473bd135da8 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -1421,6 +1421,8 @@ size_t ieee80211_ie_split_ric(const u8 *ies, size_t ielen, ies[pos + ext], ext == 2)) pos = skip_ie(ies, ielen, pos); + else + break; } } else { pos = skip_ie(ies, ielen, pos);