| From 58ebacc66bd11be2327edcefc79de94bd6f5bb4a Mon Sep 17 00:00:00 2001 |
| From: "Luis R. Rodriguez" <mcgrof@qca.qualcomm.com> |
| Date: Tue, 8 Nov 2011 14:28:06 -0800 |
| Subject: cfg80211: fix bug on regulatory core exit on access to last_request |
| |
| From: "Luis R. Rodriguez" <mcgrof@qca.qualcomm.com> |
| |
| commit 58ebacc66bd11be2327edcefc79de94bd6f5bb4a upstream. |
| |
| Commit 4d9d88d1 by Scott James Remnant <keybuk@google.com> added |
| the .uevent() callback for the regulatory device used during |
| the platform device registration. The change was done to account |
| for queuing up udev change requests through udevadm triggers. |
| The change also meant that upon regulatory core exit we will now |
| send a uevent() but the uevent() callback, reg_device_uevent(), |
| also accessed last_request. Right before commiting device suicide |
| we free'd last_request but never set it to NULL so |
| platform_device_unregister() would lead to bogus kernel paging |
| request. Fix this and also simply supress uevents right before |
| we commit suicide as they are pointless. |
| |
| This fix is required for kernels >= v2.6.39 |
| |
| $ git describe --contains 4d9d88d1 |
| v2.6.39-rc1~468^2~25^2^2~21 |
| |
| The impact of not having this present is that a bogus paging |
| access may occur (only read) upon cfg80211 unload time. You |
| may also get this BUG complaint below. Although Johannes |
| could not reproduce the issue this fix is theoretically correct. |
| |
| mac80211_hwsim: unregister radios |
| mac80211_hwsim: closing netlink |
| BUG: unable to handle kernel paging request at ffff88001a06b5ab |
| IP: [<ffffffffa030df9a>] reg_device_uevent+0x1a/0x50 [cfg80211] |
| PGD 1836063 PUD 183a063 PMD 1ffcb067 PTE 1a06b160 |
| Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC |
| CPU 0 |
| Modules linked in: cfg80211(-) [last unloaded: mac80211] |
| |
| Pid: 2279, comm: rmmod Tainted: G W 3.1.0-wl+ #663 Bochs Bochs |
| RIP: 0010:[<ffffffffa030df9a>] [<ffffffffa030df9a>] reg_device_uevent+0x1a/0x50 [cfg80211] |
| RSP: 0000:ffff88001c5f9d58 EFLAGS: 00010286 |
| RAX: 0000000000000000 RBX: ffff88001d2eda88 RCX: ffff88001c7468fc |
| RDX: ffff88001a06b5a0 RSI: ffff88001c7467b0 RDI: ffff88001c7467b0 |
| RBP: ffff88001c5f9d58 R08: 000000000000ffff R09: 000000000000ffff |
| R10: 0000000000000000 R11: 0000000000000001 R12: ffff88001c7467b0 |
| R13: ffff88001d2eda78 R14: ffffffff8164a840 R15: 0000000000000001 |
| FS: 00007f8a91d8a6e0(0000) GS:ffff88001fc00000(0000) knlGS:0000000000000000 |
| CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b |
| CR2: ffff88001a06b5ab CR3: 000000001c62e000 CR4: 00000000000006f0 |
| DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 |
| DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 |
| Process rmmod (pid: 2279, threadinfo ffff88001c5f8000, task ffff88000023c780) |
| Stack: |
| ffff88001c5f9d98 ffffffff812ff7e5 ffffffff8176ab3d ffff88001c7468c2 |
| 000000000000ffff ffff88001d2eda88 ffff88001c7467b0 ffff880000114820 |
| ffff88001c5f9e38 ffffffff81241dc7 ffff88001c5f9db8 ffffffff81040189 |
| Call Trace: |
| [<ffffffff812ff7e5>] dev_uevent+0xc5/0x170 |
| [<ffffffff81241dc7>] kobject_uevent_env+0x1f7/0x490 |
| [<ffffffff81040189>] ? sub_preempt_count+0x29/0x60 |
| [<ffffffff814cab1a>] ? _raw_spin_unlock_irqrestore+0x4a/0x90 |
| [<ffffffff81305307>] ? devres_release_all+0x27/0x60 |
| [<ffffffff8124206b>] kobject_uevent+0xb/0x10 |
| [<ffffffff812fee27>] device_del+0x157/0x1b0 |
| [<ffffffff8130377d>] platform_device_del+0x1d/0x90 |
| [<ffffffff81303b76>] platform_device_unregister+0x16/0x30 |
| [<ffffffffa030fffd>] regulatory_exit+0x5d/0x180 [cfg80211] |
| [<ffffffffa032bec3>] cfg80211_exit+0x2b/0x45 [cfg80211] |
| [<ffffffff8109a84c>] sys_delete_module+0x16c/0x220 |
| [<ffffffff8108a23e>] ? trace_hardirqs_on_caller+0x7e/0x120 |
| [<ffffffff814cba02>] system_call_fastpath+0x16/0x1b |
| Code: <all your base are belong to me> |
| RIP [<ffffffffa030df9a>] reg_device_uevent+0x1a/0x50 [cfg80211] |
| RSP <ffff88001c5f9d58> |
| CR2: ffff88001a06b5ab |
| ---[ end trace 147c5099a411e8c0 ]--- |
| |
| Reported-by: Johannes Berg <johannes@sipsolutions.net> |
| Cc: Scott James Remnant <keybuk@google.com> |
| Signed-off-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com> |
| Signed-off-by: John W. Linville <linville@tuxdriver.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| net/wireless/reg.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| --- a/net/wireless/reg.c |
| +++ b/net/wireless/reg.c |
| @@ -2254,6 +2254,9 @@ void /* __init_or_exit */ regulatory_exi |
| |
| kfree(last_request); |
| |
| + last_request = NULL; |
| + dev_set_uevent_suppress(®_pdev->dev, true); |
| + |
| platform_device_unregister(reg_pdev); |
| |
| spin_lock_bh(®_pending_beacons_lock); |