[PATCH AUTOSEL 5.11 25/67] drm/hisilicon: Fix use-after-free

From: Sasha Levin
Date: Wed Feb 24 2021 - 08:10:21 EST


From: Tian Tao <tiantao6@xxxxxxxxxxxxx>

[ Upstream commit c855af2f9c5c60760fd1bed7889a81bc37d2591d ]

Fix the problem of dev being released twice.
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 75 PID: 15700 at lib/refcount.c:28 refcount_warn_saturate+0xd4/0x150
CPU: 75 PID: 15700 Comm: rmmod Tainted: G E 5.10.0-rc3+ #3
Hardware name: Huawei TaiShan 200 (Model 2280)/BC82AMDDA, BIOS 0.88 07/24/2019
pstate: 40400009 (nZcv daif +PAN -UAO -TCO BTYPE=--)
pc : refcount_warn_saturate+0xd4/0x150
lr : refcount_warn_saturate+0xd4/0x150
sp : ffff2028150cbc00
x29: ffff2028150cbc00 x28: ffff2028150121c0
x27: 0000000000000000 x26: 0000000000000000
x25: 0000000000000000 x24: 0000000000000003
x23: 0000000000000000 x22: ffff2028150cbc90
x21: ffff2020038a30a8 x20: ffff2028150cbc90
x19: ffff0020cd938020 x18: 0000000000000010
x17: 0000000000000000 x16: 0000000000000000
x15: ffffffffffffffff x14: ffff2028950cb88f
x13: ffff2028150cb89d x12: 0000000000000000
x11: 0000000005f5e0ff x10: ffff2028150cb800
x9 : 00000000ffffffd0 x8 : 75203b776f6c6672
x7 : ffff800011a6f7c8 x6 : 0000000000000001
x5 : 0000000000000000 x4 : 0000000000000000
x3 : 0000000000000000 x2 : ffff202ffe2f9dc0
x1 : ffffa02fecf40000 x0 : 0000000000000026
Call trace:
refcount_warn_saturate+0xd4/0x150
devm_drm_dev_init_release+0x50/0x70
devm_action_release+0x20/0x30
release_nodes+0x13c/0x218
devres_release_all+0x80/0x170
device_release_driver_internal+0x128/0x1f0
driver_detach+0x6c/0xe0
bus_remove_driver+0x74/0x100
driver_unregister+0x34/0x60
pci_unregister_driver+0x24/0xd8
hibmc_pci_driver_exit+0x14/0xe858 [hibmc_drm]
__arm64_sys_delete_module+0x1fc/0x2d0
el0_svc_common.constprop.3+0xa8/0x188
do_el0_svc+0x80/0xa0
el0_sync_handler+0x8c/0xb0
el0_sync+0x15c/0x180
CPU: 75 PID: 15700 Comm: rmmod Tainted: G E 5.10.0-rc3+ #3
Hardware name: Huawei TaiShan 200 (Model 2280)/BC82AMDDA, BIOS 0.88 07/24/2019
Call trace:
dump_backtrace+0x0/0x208
show_stack+0x2c/0x40
dump_stack+0xd8/0x10c
__warn+0xac/0x128
report_bug+0xcc/0x180
bug_handler+0x24/0x78
call_break_hook+0x80/0xa0
brk_handler+0x28/0x68
do_debug_exception+0x9c/0x148
el1_sync_handler+0x7c/0x128
el1_sync+0x80/0x100
refcount_warn_saturate+0xd4/0x150
devm_drm_dev_init_release+0x50/0x70
devm_action_release+0x20/0x30
release_nodes+0x13c/0x218
devres_release_all+0x80/0x170
device_release_driver_internal+0x128/0x1f0
driver_detach+0x6c/0xe0
bus_remove_driver+0x74/0x100
driver_unregister+0x34/0x60
pci_unregister_driver+0x24/0xd8
hibmc_pci_driver_exit+0x14/0xe858 [hibmc_drm]
__arm64_sys_delete_module+0x1fc/0x2d0
el0_svc_common.constprop.3+0xa8/0x188
do_el0_svc+0x80/0xa0
el0_sync_handler+0x8c/0xb0
el0_sync+0x15c/0x180
---[ end trace 00718630d6e5ff18 ]---

Signed-off-by: Tian Tao <tiantao6@xxxxxxxxxxxxx>
Acked-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/1607941973-32287-1-git-send-email-tiantao6@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
index d845657fd99cc..426f5fb20fadc 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
@@ -366,7 +366,6 @@ static void hibmc_pci_remove(struct pci_dev *pdev)

drm_dev_unregister(dev);
hibmc_unload(dev);
- drm_dev_put(dev);
}

static const struct pci_device_id hibmc_pci_table[] = {
--
2.27.0