From 2784fe915cd25adf23ea28534019308d8a144721 Mon Sep 17 00:00:00 2001 From: "Luis R. Rodriguez" Date: Wed, 15 Dec 2010 19:24:11 -0800 Subject: [PATCH] cfg80211: fix null pointer dereference with a custom regulatory request Once we moved the core regulatory request to the queue and let the scheduler process it last_request will have been left NULL until the schedular decides to process the first request. When this happens and we are loading a driver with a custom regulatory request like all Atheros drivers we end up with a NULL pointer dereference. We fix this by checking if the request was a custom one. BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 IP: [] freq_reg_info_regd.clone.2+0x27/0x130 [cfg80211] PGD 71f91067 PUD 712b2067 PMD 0 Oops: 0000 [#1] PREEMPT SMP last sysfs file: /sys/devices/pci0000:00/0000:00:1d.7/usb2/2-1/firmware/2-1/loading CPU 0 Modules linked in: ath9k_htc(+) ath9k_common ath9k_hw ath Pid: 3094, comm: insmod Tainted: G W 2.6.37-rc5-wl #16 INVALID/28427ZQ RIP: 0010:[] [] freq_reg_info_regd.clone.2+0x27/0x130 [cfg80211] RSP: 0018:ffff88007045db78 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffffffffa047d9a0 RCX: ffff88007045dbd0 RDX: 0000000000004e20 RSI: 000000000024cde0 RDI: ffff8800700483e0 RBP: ffff88007045db98 R08: ffffffffa02f5b40 R09: 0000000000000001 R10: 000000000000000e R11: 0000000000000001 R12: 0000000000000000 R13: ffff88007004e3b0 R14: 0000000000000000 R15: ffff880070048340 FS: 00007f635a707700(0000) GS:ffff880077400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000004 CR3: 00000000708a9000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process insmod (pid: 3094, threadinfo ffff88007045c000, task ffff8800713e3ec0) Stack: ffffffffa047d9a0 0000000000000000 ffff88007004e3b0 0000000000000000 ffff88007045dc08 ffffffffa016e147 000000007045dc08 0000000000000002 ffff8800700483e0 ffffffffa02f5b40 ffff88007045dbd8 0000000000000000 Call Trace: [] wiphy_apply_custom_regulatory+0x137/0x1d0 [cfg80211] [] ? ath9k_reg_notifier+0x0/0x50 [ath9k_htc] [] ath_regd_init+0x347/0x430 [ath] [] ath9k_htc_probe_device+0x6c5/0x960 [ath9k_htc] [] ath9k_htc_hw_init+0xc/0x30 [ath9k_htc] [] ath9k_hif_usb_probe+0x216/0x3b0 [ath9k_htc] [] usb_probe_interface+0x10c/0x210 [usbcore] [] driver_probe_device+0x96/0x1c0 [] __driver_attach+0xa3/0xb0 [] ? __driver_attach+0x0/0xb0 [] bus_for_each_dev+0x5e/0x90 [] driver_attach+0x19/0x20 [] bus_add_driver+0x168/0x320 [] driver_register+0x71/0x140 [] ? __raw_spin_lock_init+0x38/0x70 [] usb_register_driver+0xdc/0x190 [usbcore] [] ? ath9k_htc_init+0x0/0x4f [ath9k_htc] [] ath9k_hif_usb_init+0x1e/0x20 [ath9k_htc] [] ath9k_htc_init+0x2b/0x4f [ath9k_htc] [] do_one_initcall+0x3f/0x180 [] sys_init_module+0xbb/0x200 [] system_call_fastpath+0x16/0x1b Code: RIP [] freq_reg_info_regd.clone.2+0x27/0x130 [cfg80211] RSP CR2: 0000000000000004 ---[ end trace 79e4193601c8b713 ]--- Reported-by: Sujith Manoharan Signed-off-by: Luis R. Rodriguez Signed-off-by: John W. Linville --- include/net/cfg80211.h | 4 +++- net/wireless/reg.c | 3 ++- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 3d1c09b777e8..6dc665a727c2 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -1419,7 +1419,9 @@ struct ieee80211_txrx_stypes { /** * struct wiphy - wireless hardware description - * @reg_notifier: the driver's regulatory notification callback + * @reg_notifier: the driver's regulatory notification callback, + * note that if your driver uses wiphy_apply_custom_regulatory() + * the reg_notifier's request can be passed as NULL * @regd: the driver's regulatory domain, if one was requested via * the regulatory_hint() API. This can be used by the driver * on the reg_notifier() if it chooses to ignore future diff --git a/net/wireless/reg.c b/net/wireless/reg.c index 5ed615f94e0c..99d41831d76e 100644 --- a/net/wireless/reg.c +++ b/net/wireless/reg.c @@ -661,7 +661,8 @@ static int freq_reg_info_regd(struct wiphy *wiphy, * Follow the driver's regulatory domain, if present, unless a country * IE has been processed or a user wants to help complaince further */ - if (last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE && + if (!custom_regd && + last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE && last_request->initiator != NL80211_REGDOM_SET_BY_USER && wiphy->regd) regd = wiphy->regd; -- 2.20.1