From 4c4d684a55fc01dac6bee696efc56b96d0e6c03a Mon Sep 17 00:00:00 2001 From: Ujjal Roy Date: Wed, 4 Dec 2013 17:27:34 +0530 Subject: [PATCH 1/2] cfg80211: fix WARN_ON for re-association to the expired BSS cfg80211 allows re-association in managed mode and if a user wants to re-associate to the same AP network after the time period of IEEE80211_SCAN_RESULT_EXPIRE, cfg80211 warns with the following message on receiving the connect result event. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 13984 at net/wireless/sme.c:658 __cfg80211_connect_result+0x3a6/0x3e0 [cfg80211]() Call Trace: [] dump_stack+0x46/0x58 [] warn_slowpath_common+0x87/0xb0 [] warn_slowpath_null+0x15/0x20 [] __cfg80211_connect_result+0x3a6/0x3e0 [cfg80211] [] ? update_rq_clock+0x2b/0x50 [] ? update_curr+0x1/0x160 [] cfg80211_process_wdev_events+0xb2/0x1c0 [cfg80211] [] ? pick_next_task_fair+0x63/0x170 [] cfg80211_process_rdev_events+0x38/0x90 [cfg80211] [] cfg80211_event_work+0x1d/0x30 [cfg80211] [] process_one_work+0x17f/0x420 [] worker_thread+0x11a/0x370 [] ? rescuer_thread+0x2f0/0x2f0 [] kthread+0xbb/0xc0 [] ? kthread_create_on_node+0x120/0x120 [] ret_from_fork+0x7c/0xb0 [] ? kthread_create_on_node+0x120/0x120 ---[ end trace 61f3bddc9c4981f7 ]--- The reason is that, in connect result event cfg80211 unholds the BSS to which the device is associated (and was held so far). So, for the event with status successful, when cfg80211 wants to get that BSS from the device's BSS list it gets a NULL BSS because the BSS has been expired and unheld already. Fix it by reshuffling the code. Signed-off-by: Ujjal Roy Signed-off-by: Johannes Berg --- net/wireless/sme.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/net/wireless/sme.c b/net/wireless/sme.c index 65f800890d70..d3c5bd7c6b51 100644 --- a/net/wireless/sme.c +++ b/net/wireless/sme.c @@ -632,6 +632,16 @@ void __cfg80211_connect_result(struct net_device *dev, const u8 *bssid, } #endif + if (!bss && (status == WLAN_STATUS_SUCCESS)) { + WARN_ON_ONCE(!wiphy_to_dev(wdev->wiphy)->ops->connect); + bss = cfg80211_get_bss(wdev->wiphy, NULL, bssid, + wdev->ssid, wdev->ssid_len, + WLAN_CAPABILITY_ESS, + WLAN_CAPABILITY_ESS); + if (bss) + cfg80211_hold_bss(bss_from_pub(bss)); + } + if (wdev->current_bss) { cfg80211_unhold_bss(wdev->current_bss); cfg80211_put_bss(wdev->wiphy, &wdev->current_bss->pub); @@ -649,16 +659,8 @@ void __cfg80211_connect_result(struct net_device *dev, const u8 *bssid, return; } - if (!bss) { - WARN_ON_ONCE(!wiphy_to_dev(wdev->wiphy)->ops->connect); - bss = cfg80211_get_bss(wdev->wiphy, NULL, bssid, - wdev->ssid, wdev->ssid_len, - WLAN_CAPABILITY_ESS, - WLAN_CAPABILITY_ESS); - if (WARN_ON(!bss)) - return; - cfg80211_hold_bss(bss_from_pub(bss)); - } + if (WARN_ON(!bss)) + return; wdev->current_bss = bss_from_pub(bss); From bd02cd2549cfcdfc57cb5ce57ffc3feb94f70575 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 16 Dec 2013 12:04:36 +0100 Subject: [PATCH 2/2] radiotap: fix bitmap-end-finding buffer overrun Evan Huus found (by fuzzing in wireshark) that the radiotap iterator code can access beyond the length of the buffer if the first bitmap claims an extension but then there's no data at all. Fix this. Cc: stable@vger.kernel.org Reported-by: Evan Huus Signed-off-by: Johannes Berg --- net/wireless/radiotap.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/wireless/radiotap.c b/net/wireless/radiotap.c index a271c27fac77..722da616438c 100644 --- a/net/wireless/radiotap.c +++ b/net/wireless/radiotap.c @@ -124,6 +124,10 @@ int ieee80211_radiotap_iterator_init( /* find payload start allowing for extended bitmap(s) */ if (iterator->_bitmap_shifter & (1<_arg - + (unsigned long)iterator->_rtheader + sizeof(uint32_t) > + (unsigned long)iterator->_max_length) + return -EINVAL; while (get_unaligned_le32(iterator->_arg) & (1 << IEEE80211_RADIOTAP_EXT)) { iterator->_arg += sizeof(uint32_t);