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authorLuis R. Rodriguez <lrodriguez@atheros.com>2009-05-02 00:34:15 -0400
committerJohn W. Linville <linville@tuxdriver.com>2009-05-04 16:22:13 -0400
commitb1ed8ddd21a2d7acf8efbb60a112ea5c9f914159 (patch)
tree3e39b43a2b4a8454e8e718153fd51fabff4a9da1 /net
parentac46d48e00349c63650b3cc6f9460fcc183da6a6 (diff)
downloadlinux-b1ed8ddd21a2d7acf8efbb60a112ea5c9f914159.tar.bz2
cfg80211: fix bug while trying to process beacon hints on init
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: Alan Jenkins <alan-jenkins@tuffmail.co.uk> Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net')
-rw-r--r--net/wireless/reg.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 3a734949769d..974b127aea66 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -1134,7 +1134,8 @@ static bool reg_is_world_roaming(struct wiphy *wiphy)
if (is_world_regdom(cfg80211_regdomain->alpha2) ||
(wiphy->regd && is_world_regdom(wiphy->regd->alpha2)))
return true;
- if (last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
+ if (last_request &&
+ last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
wiphy->custom_regulatory)
return true;
return false;
@@ -1143,6 +1144,12 @@ static bool reg_is_world_roaming(struct wiphy *wiphy)
/* Reap the advantages of previously found beacons */
static void reg_process_beacons(struct wiphy *wiphy)
{
+ /*
+ * Means we are just firing up cfg80211, so no beacons would
+ * have been processed yet.
+ */
+ if (!last_request)
+ return;
if (!reg_is_world_roaming(wiphy))
return;
wiphy_update_beacon_reg(wiphy);