[PATCH] ASoC: dapm: delete dapm_kcontrol_data paths entry before freeing
From: Srinivas Kandagatla
Date: Fri Jun 01 2018 - 18:56:04 EST
dapm_kcontrol_data is freed as part of dapm_kcontrol_free(), leaving the
paths list pointer dangling in the list.
This leads to system crash when we try to unload and reload sound card.
I hit this bug during ADSP crash/reboot test case on Dragon board DB410c.
Below is the kernel BUG with SLAB Poisoning
=============================================================================
BUG kmalloc-128 (Tainted: G W ): Poison overwritten
-----------------------------------------------------------------------------
Disabling lock debugging due to kernel taint
INFO: 0xffff80003cf1c310-0xffff80003cf1c31f. First byte 0x10 instead of 0x6b
INFO: Allocated in dapm_kcontrol_data_alloc.isra.37+0x34/0x2a8 age=6929 cpu=0 pid=50
__slab_alloc.isra.24+0x24/0x38
kmem_cache_alloc+0x190/0x1d8
dapm_kcontrol_data_alloc.isra.37+0x34/0x2a8
dapm_create_or_share_kcontrol+0x1d4/0x290
snd_soc_dapm_new_widgets+0x410/0x568
snd_soc_register_card+0xa58/0xcd0
apq8016_sbc_bind+0x31c/0x458
try_to_bring_up_master+0x204/0x2e8
component_add+0x94/0x178
q6pcm_routing_probe+0x38/0x48
platform_drv_probe+0x58/0xb8
driver_probe_device+0x324/0x478
__device_attach_driver+0xa8/0x160
bus_for_each_drv+0x48/0x98
__device_attach+0xc0/0x158
device_initial_probe+0x10/0x18
INFO: Freed in dapm_kcontrol_free+0x40/0x50 age=3135 cpu=1 pid=1792
kfree+0x1bc/0x1d0
dapm_kcontrol_free+0x40/0x50
snd_ctl_free_one+0x20/0x38
snd_ctl_remove+0xf0/0x108
snd_ctl_dev_free+0x3c/0x70
__snd_device_free+0x50/0x88
snd_device_free_all+0x2c/0x50
release_card_device+0x1c/0x78
device_release+0x34/0x98
kobject_put+0x90/0x1f0
put_device+0x14/0x20
snd_card_free+0x54/0x70
snd_soc_unregister_card+0x84/0x138
snd_soc_unregister_component+0xa4/0xd0
q6routing_dai_unbind+0x44/0x78
component_unbind.isra.4+0x28/0x50
INFO: Slab 0xffff7e0000f3c700 objects=25 used=0 fp=0xffff80003cf1fc80 flags=0xfffc00000008100
INFO: Object 0x (ptrval) @offset=768 fp=0x (ptrval)
Redzone (ptrval): bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................
Redzone (ptrval): bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................
Redzone (ptrval): bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................
Redzone (ptrval): bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................
Redzone (ptrval): bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................
Redzone (ptrval): bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................
Redzone (ptrval): bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................
Redzone (ptrval): bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................
Object (ptrval): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object (ptrval): 10 c3 f1 3c 00 80 ff ff 10 c3 f1 3c 00 80 ff ff ...<.......<....
Object (ptrval): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object (ptrval): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object (ptrval): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object (ptrval): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object (ptrval): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object (ptrval): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk.
Redzone (ptrval): bb bb bb bb bb bb bb bb ........
Padding (ptrval): 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
Padding (ptrval): 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
Padding (ptrval): 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
Padding (ptrval): 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
CPU: 1 PID: 1792 Comm: sh Tainted: G B W 4.17.0-rc7-02229-gb429ee402d16-dirty #202
Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
Call trace:
dump_backtrace+0x0/0x1b0
show_stack+0x14/0x20
dump_stack+0x9c/0xbc
print_trailer+0x124/0x1d8
check_bytes_and_report+0xe8/0x120
check_object+0x24c/0x288
__free_slab+0x9c/0x2f0
discard_slab+0x60/0x88
__slab_free+0x35c/0x3e8
kfree+0x1bc/0x1d0
snd_soc_dapm_free_widget+0xac/0xd0
snd_soc_dapm_free+0x64/0xb8
soc_remove_component+0x50/0x80
soc_remove_dai_links+0x110/0x208
snd_soc_unregister_card+0x9c/0x138
snd_soc_unregister_component+0xa4/0xd0
q6routing_dai_unbind+0x44/0x78
component_unbind.isra.4+0x28/0x50
component_unbind_all+0xc0/0xe8
apq8016_sbc_unbind+0x50/0xa0
take_down_master+0x24/0x48
component_del+0x90/0x130
q6afe_dai_dev_remove+0x40/0x68
platform_drv_remove+0x24/0x50
device_release_driver_internal+0x170/0x208
device_release_driver+0x14/0x20
bus_remove_device+0xcc/0x150
device_del+0x10c/0x310
platform_device_del.part.3+0x24/0x90
platform_device_unregister+0x18/0x30
of_platform_device_destroy+0x94/0x98
q6afe_remove+0x20/0x38
apr_device_remove+0x30/0x70
device_release_driver_internal+0x170/0x208
device_release_driver+0x14/0x20
bus_remove_device+0xcc/0x150
device_del+0x10c/0x310
device_unregister+0x1c/0x70
apr_remove_device+0xc/0x18
device_for_each_child+0x50/0x80
apr_remove+0x18/0x20
rpmsg_dev_remove+0x38/0x68
device_release_driver_internal+0x170/0x208
device_release_driver+0x14/0x20
bus_remove_device+0xcc/0x150
device_del+0x10c/0x310
device_unregister+0x1c/0x70
qcom_smd_remove_device+0xc/0x18
device_for_each_child+0x50/0x80
qcom_smd_unregister_edge+0x3c/0x70
smd_subdev_remove+0x18/0x28
rproc_stop+0x48/0xd8
rproc_shutdown+0x60/0xe8
state_store+0xbc/0xf8
dev_attr_store+0x18/0x28
sysfs_kf_write+0x3c/0x50
kernfs_fop_write+0x118/0x1e0
__vfs_write+0x18/0x110
vfs_write+0xa4/0x1a8
ksys_write+0x48/0xb0
sys_write+0xc/0x18
el0_svc_naked+0x30/0x34
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
sound/soc/soc-dapm.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index 1e9a36389667..36a39ba30226 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -433,6 +433,8 @@ static int dapm_kcontrol_data_alloc(struct snd_soc_dapm_widget *widget,
static void dapm_kcontrol_free(struct snd_kcontrol *kctl)
{
struct dapm_kcontrol_data *data = snd_kcontrol_chip(kctl);
+
+ list_del(&data->paths);
kfree(data->wlist);
kfree(data);
}
--
2.16.2