• Luis R. Rodriguez's avatar
    cfg80211: fix bug while trying to process beacon hints on init · b1ed8ddd
    Luis R. Rodriguez authored
    During initialization we would not have received any beacons
    so skip processing reg beacon hints, also adds a check to
    reg_is_world_roaming() for last_request before accessing its
    fields.
    
    This should fix this:
    
    BUG: unable to handle kernel NULL pointer dereference at
    
    IP: [<e0171332>] wiphy_update_regulatory+0x20f/0x295
    
    *pdpt = 0000000008bf1001 *pde = 0000000000000000
    Oops: 0000 [#1]
    last sysfs file: /sys/class/backlight/eeepc/brightness
    Modules linked in: ath5k(+) mac80211 led_class cfg80211
    go_bit cfbcopyarea cfbimgblt cfbfillrect ipv6
    ydev usual_tables(P) snd_hda_codec_realtek snd_hda_intel
    nd_hwdep uhci_hcd snd_pcm_oss snd_mixer_oss i2c_i801
    e serio_raw i2c_core pcspkr atl2 snd_pcm intel_agp
    re agpgart eeepc_laptop snd_page_alloc ac video backlight
    rfkill button processor evdev thermal fan ata_generic
    
    Pid: 2909, comm: modprobe Tainted: Pc #112) 701
    EIP: 0060:[<e0171332>] EFLAGS: 00010246 CPU: 0
    EIP is at wiphy_update_regulatory+0x20f/0x295 [cfg80211]
    EAX: 00000000 EBX: c5da0000 ECX: 00000000 EDX: c5da0060
    ESI: 0000001a EDI: c5da0060 EBP: df3bdd70 ESP: df3bdd40
     DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
    Process modprobe (pid: 2909, ti=df3bc000 task=c5d030000)
    Stack:
     df3bdd90 c5da0060 c04277e0 00000001 00000044 c04277e402
     00000002 c5da0000 0000001a c5da0060 df3bdda8 e01706a2 02
     00000282 000080d0 00000068 c5d53500 00000080 0000028240
    Call Trace:
     [<e01706a2>] ? wiphy_register+0x122/0x1b7 [cfg80211]
     [<e0328e02>] ? ieee80211_register_hw+0xd8/0x346
     [<e06a7c9f>] ? ath5k_hw_set_bssid_mask+0x71/0x78 [ath5k]
     [<e06b0c52>] ? ath5k_pci_probe+0xa5c/0xd0a [ath5k]
     [<c01a6037>] ? sysfs_find_dirent+0x16/0x27
     [<c01fec95>] ? local_pci_probe+0xe/0x10
     [<c01ff526>] ? pci_device_probe+0x48/0x66
     [<c024c9fd>] ? driver_probe_device+0x7f/0xf2
     [<c024cab3>] ? __driver_attach+0x43/0x5f
     [<c024c0af>] ? bus_for_each_dev+0x39/0x5a
     [<c024c8d0>] ? driver_attach+0x14/0x16
     [<c024ca70>] ? __driver_attach+0x0/0x5f
     [<c024c5b3>] ? bus_add_driver+0xd7/0x1e7
     [<c024ccb9>] ? driver_register+0x7b/0xd7
     [<c01ff827>] ? __pci_register_driver+0x32/0x85
     [<e00a8018>] ? init_ath5k_pci+0x18/0x30 [ath5k]
     [<c0101131>] ? _stext+0x49/0x10b
     [<e00a8000>] ? init_ath5k_pci+0x0/0x30 [ath5k]
     [<c012f452>] ? __blocking_notifier_call_chain+0x40/0x4c
     [<c013a714>] ? sys_init_module+0x87/0x18b
     [<c0102804>] ? sysenter_do_call+0x12/0x22
    Code: b8 da 17 e0 83 c0 04 e8 92 f9 ff ff 84 c0 75 2a 8b
    85 c0 74 0c 83 c0 04 e8 7c f9 ff ff 84 c0 75 14 a1 bc da
    4 03 74 66 8b 4d d4 80 79 08 00 74 5d a1 e0 d2 17 e0 48
    EIP: [<e0171332>] wiphy_update_regulatory+0x20f/0x295
    SP 0068:df3bdd40
    CR2: 0000000000000004
    ---[ end trace 830f2dd2a95fd1a8 ]---
    
    This issue is hard to reproduce, but it was noticed and discussed on
    this thread:
    
    http://marc.info/?t=123938022700005&r=1&w=2
    
    Cc: stable@kernel.org
    Reported-by: default avatarAlan Jenkins <alan-jenkins@tuffmail.co.uk>
    Signed-off-by: default avatarLuis R. Rodriguez <lrodriguez@atheros.com>
    Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
    b1ed8ddd
reg.c 58.2 KB