[PATCH] platform/x86: asus-wireless: Fix NULL pointer dereference
From: JoÃo Paulo Rechi Vita
Date: Sat Apr 07 2018 - 01:41:07 EST
When the module is removed the led workqueue is destroyed in the remove
callback, before the led device is unregistered from the led subsystem.
This leads to a NULL pointer derefence when the led device is
unregistered automatically later as part of the module removal cleanup.
Bellow is the backtrace showing the problem.
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: __queue_work+0x8c/0x410
PGD 0 P4D 0
Oops: 0000 [#1] SMP NOPTI
Modules linked in: ccm edac_mce_amd kvm_amd kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel aes_x86_64 joydev crypto_simd asus_nb_wmi glue_helper uvcvideo snd_hda_codec_conexant snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_intel asus_wmi snd_hda_codec cryptd snd_hda_core sparse_keymap videobuf2_vmalloc arc4 videobuf2_memops snd_hwdep input_leds videobuf2_v4l2 ath9k psmouse videobuf2_core videodev ath9k_common snd_pcm ath9k_hw media fam15h_power ath k10temp snd_timer mac80211 i2c_piix4 r8169 mii mac_hid cfg80211 asus_wireless(-) snd soundcore wmi shpchp 8250_dw ip_tables x_tables amdkfd amd_iommu_v2 amdgpu radeon chash i2c_algo_bit drm_kms_helper syscopyarea serio_raw sysfillrect sysimgblt fb_sys_fops ahci ttm libahci drm video
CPU: 3 PID: 2177 Comm: rmmod Not tainted 4.15.0-5-generic #6+dev94.b4287e5bem1-Endless
Hardware name: ASUSTeK COMPUTER INC. X555DG/X555DG, BIOS 5.011 05/05/2015
RIP: 0010:__queue_work+0x8c/0x410
RSP: 0018:ffffbe8cc249fcd8 EFLAGS: 00010086
RAX: ffff992ac6810800 RBX: 0000000000000000 RCX: 0000000000000008
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff992ac6400e18
RBP: ffffbe8cc249fd18 R08: ffff992ac6400db0 R09: 0000000000000000
R10: 0000000000000040 R11: ffff992ac6400dd8 R12: 0000000000002000
R13: ffff992abd762e00 R14: ffff992abd763e38 R15: 000000000001ebe0
FS: 00007f318203e700(0000) GS:ffff992aced80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001c720e000 CR4: 00000000001406e0
Call Trace:
queue_work_on+0x38/0x40
led_state_set+0x2c/0x40 [asus_wireless]
led_set_brightness_nopm+0x14/0x40
led_set_brightness+0x37/0x60
led_trigger_set+0xfc/0x1d0
led_classdev_unregister+0x32/0xd0
devm_led_classdev_release+0x11/0x20
release_nodes+0x109/0x1f0
devres_release_all+0x3c/0x50
device_release_driver_internal+0x16d/0x220
driver_detach+0x3f/0x80
bus_remove_driver+0x55/0xd0
driver_unregister+0x2c/0x40
acpi_bus_unregister_driver+0x15/0x20
asus_wireless_driver_exit+0x10/0xb7c [asus_wireless]
SyS_delete_module+0x1da/0x2b0
entry_SYSCALL_64_fastpath+0x24/0x87
RIP: 0033:0x7f3181b65fd7
RSP: 002b:00007ffe74bcbe18 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3181b65fd7
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000555ea2559258
RBP: 0000555ea25591f0 R08: 00007ffe74bcad91 R09: 000000000000000a
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000003
R13: 00007ffe74bcae00 R14: 0000000000000000 R15: 0000555ea25591f0
Code: 01 00 00 02 0f 85 7d 01 00 00 48 63 45 d4 48 c7 c6 00 f4 fa 87 49 8b 9d 08 01 00 00 48 03 1c c6 4c 89 f7 e8 87 fb ff ff 48 85 c0 <48> 8b 3b 0f 84 c5 01 00 00 48 39 f8 0f 84 bc 01 00 00 48 89 c7
RIP: __queue_work+0x8c/0x410 RSP: ffffbe8cc249fcd8
CR2: 0000000000000000
---[ end trace 7aa4f4a232e9c39c ]---
Unregistering the led device on the remove callback before destroying the
workqueue avoids this problem.
https://bugzilla.kernel.org/show_bug.cgi?id=196097
Reported-by: Dun Hum <bitter.taste@xxxxxxx>
Signed-off-by: JoÃo Paulo Rechi Vita <jprvita@xxxxxxxxxxxx>
---
drivers/platform/x86/asus-wireless.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/platform/x86/asus-wireless.c b/drivers/platform/x86/asus-wireless.c
index 343e12547660..ecd715c82de5 100644
--- a/drivers/platform/x86/asus-wireless.c
+++ b/drivers/platform/x86/asus-wireless.c
@@ -181,6 +181,7 @@ static int asus_wireless_remove(struct acpi_device *adev)
{
struct asus_wireless_data *data = acpi_driver_data(adev);
+ devm_led_classdev_unregister(&adev->dev, &data->led);
if (data->wq)
destroy_workqueue(data->wq);
return 0;
--
2.16.3