• Ujjal Roy's avatar
    cfg80211: fix WARN_ON for re-association to the expired BSS · 4c4d684a
    Ujjal Roy authored
    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:
     [<ffffffff81747a41>] dump_stack+0x46/0x58
     [<ffffffff81045847>] warn_slowpath_common+0x87/0xb0
     [<ffffffff81045885>] warn_slowpath_null+0x15/0x20
     [<ffffffffa05345f6>] __cfg80211_connect_result+0x3a6/0x3e0 [cfg80211]
     [<ffffffff8107168b>] ? update_rq_clock+0x2b/0x50
     [<ffffffff81078c01>] ? update_curr+0x1/0x160
     [<ffffffffa05133d2>] cfg80211_process_wdev_events+0xb2/0x1c0 [cfg80211]
     [<ffffffff81079303>] ? pick_next_task_fair+0x63/0x170
     [<ffffffffa0513518>] cfg80211_process_rdev_events+0x38/0x90 [cfg80211]
     [<ffffffffa050f03d>] cfg80211_event_work+0x1d/0x30 [cfg80211]
     [<ffffffff8105f21f>] process_one_work+0x17f/0x420
     [<ffffffff8105f90a>] worker_thread+0x11a/0x370
     [<ffffffff8105f7f0>] ? rescuer_thread+0x2f0/0x2f0
     [<ffffffff8106638b>] kthread+0xbb/0xc0
     [<ffffffff810662d0>] ? kthread_create_on_node+0x120/0x120
     [<ffffffff817574bc>] ret_from_fork+0x7c/0xb0
     [<ffffffff810662d0>] ? 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: default avatarUjjal Roy <royujjal@gmail.com>
    Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
    4c4d684a
sme.c 25.4 KB