The driver is not released when ieee80211_register_hw fails in
mac80211_hwsim_create_radio, leading to the access to the unregistered (and
possibly freed) device in platform_driver_unregister:
[ 0.447547] mac80211_hwsim: ieee80211_register_hw failed (-2)
[ 0.448292] ------------[ cut here ]------------
[ 0.448854] WARNING: CPU: 0 PID: 1 at ../include/linux/kref.h:47 kobject_get+0x33/0x50()
[ 0.449839] CPU: 0 PID: 1 Comm: swapper Not tainted 3.17.0-00001-gdd46990-dirty #2
[ 0.450813] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 0.451512] 00000000 00000000 78025e38 7967c6c6 78025e68 7905e09b 7988b480 00000000
[ 0.452579] 00000001 79887d62 0000002f 79170bb3 79170bb3 78397008 79ac9d74 00000001
[ 0.453614] 78025e78 7905e15d 00000009 00000000 78025e84 79170bb3 78397000 78025e8c
[ 0.454632] Call Trace:
[ 0.454921] [<7967c6c6>] dump_stack+0x16/0x18
[ 0.455453] [<7905e09b>] warn_slowpath_common+0x6b/0x90
[ 0.456067] [<79170bb3>] ? kobject_get+0x33/0x50
[ 0.456612] [<79170bb3>] ? kobject_get+0x33/0x50
[ 0.457155] [<7905e15d>] warn_slowpath_null+0x1d/0x20
[ 0.457748] [<79170bb3>] kobject_get+0x33/0x50
[ 0.458274] [<7925824f>] get_device+0xf/0x20
[ 0.458779] [<7925b5cd>] driver_detach+0x3d/0xa0
[ 0.459331] [<7925a3ff>] bus_remove_driver+0x8f/0xb0
[ 0.459927] [<7925bf80>] ? class_unregister+0x40/0x80
[ 0.460660] [<7925bad7>] driver_unregister+0x47/0x50
[ 0.461248] [<7925c033>] ? class_destroy+0x13/0x20
[ 0.461824] [<7925d07b>] platform_driver_unregister+0xb/0x10
[ 0.462507] [<79b51ba0>] init_mac80211_hwsim+0x3e8/0x3f9
[ 0.463161] [<79b30c58>] do_one_initcall+0x106/0x1a9
[ 0.463758] [<79b517b8>] ? if_spi_init_module+0xac/0xac
[ 0.464393] [<79b517b8>] ? if_spi_init_module+0xac/0xac
[ 0.465001] [<79071935>] ? parse_args+0x2f5/0x480
[ 0.465569] [<7906b41e>] ? __usermodehelper_set_disable_depth+0x3e/0x50
[ 0.466345] [<79b30dd9>] kernel_init_freeable+0xde/0x17d
[ 0.466972] [<79b304d6>] ? do_early_param+0x7a/0x7a
[ 0.467546] [<79677b1b>] kernel_init+0xb/0xe0
[ 0.468072] [<79075f42>] ? schedule_tail+0x12/0x40
[ 0.468658] [<79686580>] ret_from_kernel_thread+0x20/0x30
[ 0.469303] [<79677b10>] ? rest_init+0xc0/0xc0
[ 0.469829] ---[ end trace ad8ac403ff8aef5c ]---
[ 0.470509] ------------[ cut here ]------------
[ 0.471047] WARNING: CPU: 0 PID: 1 at ../kernel/locking/lockdep.c:3161 __lock_acquire.isra.22+0x7aa/0xb00()
[ 0.472163] DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS)
[ 0.472774] CPU: 0 PID: 1 Comm: swapper Tainted: G W 3.17.0-00001-gdd46990-dirty #2
[ 0.473815] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 0.474492] 78025de0 78025de0 78025da0 7967c6c6 78025dd0 7905e09b 79888931 78025dfc
[ 0.475515] 00000001 79888a93 00000c59 7907f33a 7907f33a 78028000 fffe9d09 00000000
[ 0.476519] 78025de8 7905e10e 00000009 78025de0 79888931 78025dfc 78025e24 7907f33a
[ 0.477523] Call Trace:
[ 0.477821] [<7967c6c6>] dump_stack+0x16/0x18
[ 0.478352] [<7905e09b>] warn_slowpath_common+0x6b/0x90
[ 0.478976] [<7907f33a>] ? __lock_acquire.isra.22+0x7aa/0xb00
[ 0.479658] [<7907f33a>] ? __lock_acquire.isra.22+0x7aa/0xb00
[ 0.480417] [<7905e10e>] warn_slowpath_fmt+0x2e/0x30
[ 0.480479] [<7907f33a>] __lock_acquire.isra.22+0x7aa/0xb00
[ 0.480479] [<79078aa5>] ? sched_clock_cpu+0xb5/0xf0
[ 0.480479] [<7907fd06>] lock_acquire+0x56/0x70
[ 0.480479] [<7925b5e8>] ? driver_detach+0x58/0xa0
[ 0.480479] [<79682d11>] mutex_lock_nested+0x61/0x2a0
[ 0.480479] [<7925b5e8>] ? driver_detach+0x58/0xa0
[ 0.480479] [<7925b5e8>] ? driver_detach+0x58/0xa0
[ 0.480479] [<7925b5e8>] driver_detach+0x58/0xa0
[ 0.480479] [<7925a3ff>] bus_remove_driver+0x8f/0xb0
[ 0.480479] [<7925bf80>] ? class_unregister+0x40/0x80
[ 0.480479] [<7925bad7>] driver_unregister+0x47/0x50
[ 0.480479] [<7925c033>] ? class_destroy+0x13/0x20
[ 0.480479] [<7925d07b>] platform_driver_unregister+0xb/0x10
[ 0.480479] [<79b51ba0>] init_mac80211_hwsim+0x3e8/0x3f9
[ 0.480479] [<79b30c58>] do_one_initcall+0x106/0x1a9
[ 0.480479] [<79b517b8>] ? if_spi_init_module+0xac/0xac
[ 0.480479] [<79b517b8>] ? if_spi_init_module+0xac/0xac
[ 0.480479] [<79071935>] ? parse_args+0x2f5/0x480
[ 0.480479] [<7906b41e>] ? __usermodehelper_set_disable_depth+0x3e/0x50
[ 0.480479] [<79b30dd9>] kernel_init_freeable+0xde/0x17d
[ 0.480479] [<79b304d6>] ? do_early_param+0x7a/0x7a
[ 0.480479] [<79677b1b>] kernel_init+0xb/0xe0
[ 0.480479] [<79075f42>] ? schedule_tail+0x12/0x40
[ 0.480479] [<79686580>] ret_from_kernel_thread+0x20/0x30
[ 0.480479] [<79677b10>] ? rest_init+0xc0/0xc0
[ 0.480479] ---[ end trace ad8ac403ff8aef5d ]---
[ 0.495478] BUG: unable to handle kernel paging request at 00200200
[ 0.496257] IP: [<79682de5>] mutex_lock_nested+0x135/0x2a0
[ 0.496923] *pde = 00000000
[ 0.497290] Oops: 0002 [#1]
[ 0.497653] CPU: 0 PID: 1 Comm: swapper Tainted: G W 3.17.0-00001-gdd46990-dirty #2
[ 0.498659] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 0.499321] task: 78028000 ti: 78024000 task.ti: 78024000
[ 0.499955] EIP: 0060:[<79682de5>] EFLAGS: 00010097 CPU: 0
[ 0.500620] EIP is at mutex_lock_nested+0x135/0x2a0
[ 0.501145] EAX: 00200200 EBX: 78397434 ECX: 78397460 EDX: 78025e70
[ 0.501816] ESI: 00000246 EDI: 78028000 EBP: 78025e8c ESP: 78025e54
[ 0.502497] DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
[ 0.503076] CR0: 8005003b CR2: 00200200 CR3: 01b9d000 CR4: 00000690
[ 0.503773] Stack:
[ 0.503998] 00000000 00000001 00000000 7925b5e8 78397460 7925b5e8 78397474 78397460
[ 0.504944] 00200200 11111111 78025e70 78397000 79ac9d74 00000001 78025ea0 7925b5e8
[ 0.505451] 79ac9d74 fffffffe 00000001 78025ebc 7925a3ff 7a251398 78025ec8 7925bf80
[ 0.505451] Call Trace:
[ 0.505451] [<7925b5e8>] ? driver_detach+0x58/0xa0
[ 0.505451] [<7925b5e8>] ? driver_detach+0x58/0xa0
[ 0.505451] [<7925b5e8>] driver_detach+0x58/0xa0
[ 0.505451] [<7925a3ff>] bus_remove_driver+0x8f/0xb0
[ 0.505451] [<7925bf80>] ? class_unregister+0x40/0x80
[ 0.505451] [<7925bad7>] driver_unregister+0x47/0x50
[ 0.505451] [<7925c033>] ? class_destroy+0x13/0x20
[ 0.505451] [<7925d07b>] platform_driver_unregister+0xb/0x10
[ 0.505451] [<79b51ba0>] init_mac80211_hwsim+0x3e8/0x3f9
[ 0.505451] [<79b30c58>] do_one_initcall+0x106/0x1a9
[ 0.505451] [<79b517b8>] ? if_spi_init_module+0xac/0xac
[ 0.505451] [<79b517b8>] ? if_spi_init_module+0xac/0xac
[ 0.505451] [<79071935>] ? parse_args+0x2f5/0x480
[ 0.505451] [<7906b41e>] ? __usermodehelper_set_disable_depth+0x3e/0x50
[ 0.505451] [<79b30dd9>] kernel_init_freeable+0xde/0x17d
[ 0.505451] [<79b304d6>] ? do_early_param+0x7a/0x7a
[ 0.505451] [<79677b1b>] kernel_init+0xb/0xe0
[ 0.505451] [<79075f42>] ? schedule_tail+0x12/0x40
[ 0.505451] [<79686580>] ret_from_kernel_thread+0x20/0x30
[ 0.505451] [<79677b10>] ? rest_init+0xc0/0xc0
[ 0.505451] Code: 89 d8 e8 cf 9b 9f ff 8b 4f 04 8d 55 e4 89 d8 e8 72 9d 9f ff 8d 43 2c 89 c1 89 45 d8 8b 43 30 8d 55 e4 89 53 30 89 4d e4 89 45 e8 <89> 10 8b 55 dc 8b 45 e0 89 7d ec e8 db af 9f ff eb 11 90 31 c0
[ 0.505451] EIP: [<79682de5>] mutex_lock_nested+0x135/0x2a0 SS:ESP 0068:78025e54
[ 0.505451] CR2: 0000000000200200
[ 0.505451] ---[ end trace ad8ac403ff8aef5e ]---
[ 0.505451] Kernel panic - not syncing: Fatal exception
Fixes: 9ea927748ced ("mac80211_hwsim: Register and bind to driver")
Reported-by: Fengguang Wu <[email protected]>
Signed-off-by: Junjie Mao <[email protected]>
---
drivers/net/wireless/mac80211_hwsim.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index babbdc1ce741..c9ad4cf1adfb 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -1987,7 +1987,7 @@ static int mac80211_hwsim_create_radio(int channels, const char *reg_alpha2,
if (err != 0) {
printk(KERN_DEBUG "mac80211_hwsim: device_bind_driver failed (%d)\n",
err);
- goto failed_hw;
+ goto failed_bind;
}
skb_queue_head_init(&data->pending);
@@ -2183,6 +2183,8 @@ static int mac80211_hwsim_create_radio(int channels, const char *reg_alpha2,
return idx;
failed_hw:
+ device_release_driver(data->dev);
+failed_bind:
device_unregister(data->dev);
failed_drvdata:
ieee80211_free_hw(hw);
--
1.9.3
Acked-By: Martin Pitt <[email protected]>
Hello Junjie,
Junjie Mao [2014-10-28 9:31 +0800]:
> The driver is not released when ieee80211_register_hw fails in
> mac80211_hwsim_create_radio, leading to the access to the unregistered (and
> possibly freed) device in platform_driver_unregister:
Many thanks for fixing this! Sorry about that, I don't know these bits
very well.
Martin
--
Martin Pitt | http://www.piware.de
Ubuntu Developer (http://www.ubuntu.com) | Debian Developer (http://www.debian.org)
I was not familiar with the acquiring/releasing API either, until I met
with this bug...
Perhaps we can use static checkers to avoid these issues as early as
possible. Any suggestions?
Best Regards
Junjie Mao
Martin Pitt <[email protected]> writes:
> Acked-By: Martin Pitt <[email protected]>
>
> Hello Junjie,
>
> Junjie Mao [2014-10-28 9:31 +0800]:
>> The driver is not released when ieee80211_register_hw fails in
>> mac80211_hwsim_create_radio, leading to the access to the unregistered (and
>> possibly freed) device in platform_driver_unregister:
>
> Many thanks for fixing this! Sorry about that, I don't know these bits
> very well.
>
> Martin
On Wed, Oct 29, 2014 at 06:23:02PM +0800, Junjie Mao wrote:
> I was not familiar with the acquiring/releasing API either, until I met
> with this bug...
>
> Perhaps we can use static checkers to avoid these issues as early as
> possible. Any suggestions?
CC Dan. His smatch checker might be able (or could be enabled) to
handle the verification of missing device_release_driver() call.
Thanks,
Fengguang
> Martin Pitt <[email protected]> writes:
>
> > Acked-By: Martin Pitt <[email protected]>
> >
> > Hello Junjie,
> >
> > Junjie Mao [2014-10-28 9:31 +0800]:
> >> The driver is not released when ieee80211_register_hw fails in
> >> mac80211_hwsim_create_radio, leading to the access to the unregistered (and
> >> possibly freed) device in platform_driver_unregister:
> >
> > Many thanks for fixing this! Sorry about that, I don't know these bits
> > very well.
> >
> > Martin
On Tue, 2014-10-28 at 09:31 +0800, Junjie Mao wrote:
> The driver is not released when ieee80211_register_hw fails in
> mac80211_hwsim_create_radio, leading to the access to the unregistered (and
> possibly freed) device in platform_driver_unregister:
Applied.
johannes