The drvdata is not available in release. Let's just use container_of()
to get the vector_device instance. Otherwise, removing a vector device
will result in a crash:

RIP: 0033:vector_device_release+0xf/0x50
RSP: 00000000e187bc40  EFLAGS: 00010202
RAX: 0000000060028f61 RBX: 00000000600f1baf RCX: 00000000620074e0
RDX: 000000006220b9c0 RSI: 0000000060551c80 RDI: 0000000000000000
RBP: 00000000e187bc50 R08: 00000000603ad594 R09: 00000000e187bb70
R10: 000000000000135a R11: 00000000603ad422 R12: 00000000623ae028
R13: 000000006287a200 R14: 0000000062006d30 R15: 00000000623700b6
Kernel panic - not syncing: Segfault with no mm
CPU: 0 UID: 0 PID: 16 Comm: kworker/0:1 Not tainted 6.12.0-rc6-g59b723cd2adb #1
Workqueue: events mc_work_proc
Stack:
 60028f61 623ae028 e187bc80 60276fcd
 6220b9c0 603f5820 623ae028 00000000
 e187bcb0 603a2bcd 623ae000 62370010
Call Trace:
 [<60028f61>] ? vector_device_release+0x0/0x50
 [<60276fcd>] device_release+0x70/0xba
 [<603a2bcd>] kobject_put+0xba/0xe7
 [<60277265>] put_device+0x19/0x1c
 [<60281266>] platform_device_put+0x26/0x29
 [<60281e5f>] platform_device_unregister+0x2c/0x2e
 [<60029422>] vector_remove+0x52/0x58
 [<60031316>] ? mconsole_reply+0x0/0x50
 [<600310c8>] mconsole_remove+0x160/0x1cc
 [<603b19f4>] ? strlen+0x0/0x15
 [<60066611>] ? __dequeue_entity+0x1a9/0x206
 [<600666a7>] ? set_next_entity+0x39/0x63
 [<6006666e>] ? set_next_entity+0x0/0x63
 [<60038fa6>] ? um_set_signals+0x0/0x43
 [<6003070c>] mc_work_proc+0x77/0x91
 [<60057664>] process_scheduled_works+0x1b3/0x2dd
 [<60055f32>] ? assign_work+0x0/0x58
 [<60057f0a>] worker_thread+0x1e9/0x293
 [<6005406f>] ? set_pf_worker+0x0/0x64
 [<6005d65d>] ? arch_local_irq_save+0x0/0x2d
 [<6005d748>] ? kthread_exit+0x0/0x3a
 [<60057d21>] ? worker_thread+0x0/0x293
 [<6005dbf1>] kthread+0x126/0x12b
 [<600219c5>] new_thread_handler+0x85/0xb6

Cc: stable@vger.kernel.org
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
---
 arch/um/drivers/vector_kern.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/um/drivers/vector_kern.c b/arch/um/drivers/vector_kern.c
index c992da83268d..64c09db392c1 100644
--- a/arch/um/drivers/vector_kern.c
+++ b/arch/um/drivers/vector_kern.c
@@ -815,7 +815,8 @@ static struct platform_driver uml_net_driver = {
 
 static void vector_device_release(struct device *dev)
 {
-	struct vector_device *device = dev_get_drvdata(dev);
+	struct vector_device *device =
+		container_of(dev, struct vector_device, pdev.dev);
 	struct net_device *netdev = device->dev;
 
 	list_del(&device->list);
-- 
2.34.1

On 04/11/2024 16:32, Tiwei Bie wrote:
> The drvdata is not available in release. Let's just use container_of()
> to get the vector_device instance. Otherwise, removing a vector device
> will result in a crash:
> 
> RIP: 0033:vector_device_release+0xf/0x50
> RSP: 00000000e187bc40  EFLAGS: 00010202
> RAX: 0000000060028f61 RBX: 00000000600f1baf RCX: 00000000620074e0
> RDX: 000000006220b9c0 RSI: 0000000060551c80 RDI: 0000000000000000
> RBP: 00000000e187bc50 R08: 00000000603ad594 R09: 00000000e187bb70
> R10: 000000000000135a R11: 00000000603ad422 R12: 00000000623ae028
> R13: 000000006287a200 R14: 0000000062006d30 R15: 00000000623700b6
> Kernel panic - not syncing: Segfault with no mm
> CPU: 0 UID: 0 PID: 16 Comm: kworker/0:1 Not tainted 6.12.0-rc6-g59b723cd2adb #1
> Workqueue: events mc_work_proc
> Stack:
>   60028f61 623ae028 e187bc80 60276fcd
>   6220b9c0 603f5820 623ae028 00000000
>   e187bcb0 603a2bcd 623ae000 62370010
> Call Trace:
>   [<60028f61>] ? vector_device_release+0x0/0x50
>   [<60276fcd>] device_release+0x70/0xba
>   [<603a2bcd>] kobject_put+0xba/0xe7
>   [<60277265>] put_device+0x19/0x1c
>   [<60281266>] platform_device_put+0x26/0x29
>   [<60281e5f>] platform_device_unregister+0x2c/0x2e
>   [<60029422>] vector_remove+0x52/0x58
>   [<60031316>] ? mconsole_reply+0x0/0x50
>   [<600310c8>] mconsole_remove+0x160/0x1cc
>   [<603b19f4>] ? strlen+0x0/0x15
>   [<60066611>] ? __dequeue_entity+0x1a9/0x206
>   [<600666a7>] ? set_next_entity+0x39/0x63
>   [<6006666e>] ? set_next_entity+0x0/0x63
>   [<60038fa6>] ? um_set_signals+0x0/0x43
>   [<6003070c>] mc_work_proc+0x77/0x91
>   [<60057664>] process_scheduled_works+0x1b3/0x2dd
>   [<60055f32>] ? assign_work+0x0/0x58
>   [<60057f0a>] worker_thread+0x1e9/0x293
>   [<6005406f>] ? set_pf_worker+0x0/0x64
>   [<6005d65d>] ? arch_local_irq_save+0x0/0x2d
>   [<6005d748>] ? kthread_exit+0x0/0x3a
>   [<60057d21>] ? worker_thread+0x0/0x293
>   [<6005dbf1>] kthread+0x126/0x12b
>   [<600219c5>] new_thread_handler+0x85/0xb6
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
> ---
>   arch/um/drivers/vector_kern.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/um/drivers/vector_kern.c b/arch/um/drivers/vector_kern.c
> index c992da83268d..64c09db392c1 100644
> --- a/arch/um/drivers/vector_kern.c
> +++ b/arch/um/drivers/vector_kern.c
> @@ -815,7 +815,8 @@ static struct platform_driver uml_net_driver = {
>   
>   static void vector_device_release(struct device *dev)
>   {
> -	struct vector_device *device = dev_get_drvdata(dev);
> +	struct vector_device *device =
> +		container_of(dev, struct vector_device, pdev.dev);
>   	struct net_device *netdev = device->dev;
>   
>   	list_del(&device->list);

Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>

-- 
Anton R. Ivanov
Cambridgegreys Limited. Registered in England. Company Number 10273661
https://www.cambridgegreys.com/