* [PATCH v2] usb: gadget: u_serial: check Null pointer in EP callback
@ 2024-08-20 9:29 胡连勤
2024-08-20 10:15 ` Prashanth K
2024-08-20 11:51 ` gregkh
0 siblings, 2 replies; 4+ messages in thread
From: 胡连勤 @ 2024-08-20 9:29 UTC (permalink / raw)
To: gregkh@linuxfoundation.org
Cc: quic_prashk@quicinc.com, quic_jjohnson@quicinc.com,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
opensource.kernel, akpm@linux-foundation.org,
Michael Nazzareno Trimarchi
From: Lianqin Hu <hulianqin@vivo.com>
Added null pointer check to avoid system crash.
Unable to handle kernel NULL pointer dereference at
virtual address 00000000000001a8
pc : gs_read_complete+0x58/0x240
lr : usb_gadget_giveback_request+0x40/0x160
sp : ffffffc00f1539c0
x29: ffffffc00f1539c0 x28: ffffff8002a30000 x27: 0000000000000000
x26: ffffff8002a30000 x25: 0000000000000000 x24: ffffff8002a30000
x23: ffffff8002ff9a70 x22: ffffff898e7a7b00 x21: ffffff803c9af9d8
x20: ffffff898e7a7b00 x19: 00000000000001a8 x18: ffffffc0099fd098
x17: 0000000000001000 x16: 0000000080000000 x15: 0000000ac1200000
x14: 0000000000000003 x13: 000000000000d5e8 x12: 0000000355c314ac
x11: 0000000000000015 x10: 0000000000000012 x9 : 0000000000000008
x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffffff887cd12000
x5 : 0000000000000002 x4 : ffffffc00f9b07f0 x3 : ffffffc00f1538d0
x2 : 0000000000000001 x1 : 0000000000000000 x0 : 00000000000001a8
Call trace:
gs_read_complete+0x58/0x240
usb_gadget_giveback_request+0x40/0x160
dwc3_remove_requests+0x170/0x484
dwc3_ep0_out_start+0xb0/0x1d4
__dwc3_gadget_start+0x25c/0x720
kretprobe_trampoline.cfi_jt+0x0/0x8
kretprobe_trampoline.cfi_jt+0x0/0x8
udc_bind_to_driver+0x1d8/0x300
usb_gadget_probe_driver+0xa8/0x1dc
gadget_dev_desc_UDC_store+0x13c/0x188
configfs_write_iter+0x160/0x1f4
vfs_write+0x2d0/0x40c
ksys_write+0x7c/0xf0
__arm64_sys_write+0x20/0x30
invoke_syscall+0x60/0x150
el0_svc_common+0x8c/0xf8
do_el0_svc+0x28/0xa0
el0_svc+0x24/0x84
el0t_64_sync_handler+0x88/0xec
el0t_64_sync+0x1b4/0x1b8
Code: aa1f03e1 aa1303e0 52800022 2a0103e8 (88e87e62)
---[ end trace 938847327a739172 ]---
Kernel panic - not syncing: Oops: Fatal exception
Signed-off-by: Lianqin Hu <hulianqin@vivo.com>
---
v2:
- Optimize code comments
- Delete log printing
---
drivers/usb/gadget/function/u_serial.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
index b394105e55d6..65637d53bf02
--- a/drivers/usb/gadget/function/u_serial.c
+++ b/drivers/usb/gadget/function/u_serial.c
@@ -454,6 +454,14 @@ static void gs_read_complete(struct usb_ep *ep, struct usb_request *req)
{
struct gs_port *port = ep->driver_data;
+ /* When port is NULL, return to avoid panic. */
+ if (!port)
+ return;
+
/* Queue all received data until the tty layer is ready for it. */
spin_lock(&port->port_lock);
list_add_tail(&req->list, &port->read_queue);
@@ -465,6 +473,14 @@ static void gs_write_complete(struct usb_ep *ep, struct usb_request *req)
{
struct gs_port *port = ep->driver_data;
+ /* When port is NULL, return to avoid panic. */
+ if (!port)
+ return;
+
spin_lock(&port->port_lock);
list_add(&req->list, &port->write_pool);
port->write_started--;
--
2.39.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] usb: gadget: u_serial: check Null pointer in EP callback
2024-08-20 9:29 [PATCH v2] usb: gadget: u_serial: check Null pointer in EP callback 胡连勤
@ 2024-08-20 10:15 ` Prashanth K
2024-08-20 10:52 ` 答复: " 胡连勤
2024-08-20 11:51 ` gregkh
1 sibling, 1 reply; 4+ messages in thread
From: Prashanth K @ 2024-08-20 10:15 UTC (permalink / raw)
To: 胡连勤, gregkh@linuxfoundation.org
Cc: quic_jjohnson@quicinc.com, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org, opensource.kernel,
akpm@linux-foundation.org, Michael Nazzareno Trimarchi
On 20-08-24 02:59 pm, 胡连勤 wrote:
> From: Lianqin Hu <hulianqin@vivo.com>
>
> Added null pointer check to avoid system crash.
Address whats becoming Null and why its happening
>
> Unable to handle kernel NULL pointer dereference at
> virtual address 00000000000001a8
> pc : gs_read_complete+0x58/0x240
> lr : usb_gadget_giveback_request+0x40/0x160
> sp : ffffffc00f1539c0
> x29: ffffffc00f1539c0 x28: ffffff8002a30000 x27: 0000000000000000
> x26: ffffff8002a30000 x25: 0000000000000000 x24: ffffff8002a30000
> x23: ffffff8002ff9a70 x22: ffffff898e7a7b00 x21: ffffff803c9af9d8
> x20: ffffff898e7a7b00 x19: 00000000000001a8 x18: ffffffc0099fd098
> x17: 0000000000001000 x16: 0000000080000000 x15: 0000000ac1200000
> x14: 0000000000000003 x13: 000000000000d5e8 x12: 0000000355c314ac
> x11: 0000000000000015 x10: 0000000000000012 x9 : 0000000000000008
> x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffffff887cd12000
> x5 : 0000000000000002 x4 : ffffffc00f9b07f0 x3 : ffffffc00f1538d0
> x2 : 0000000000000001 x1 : 0000000000000000 x0 : 00000000000001a8
> Call trace:
> gs_read_complete+0x58/0x240
> usb_gadget_giveback_request+0x40/0x160
> dwc3_remove_requests+0x170/0x484
> dwc3_ep0_out_start+0xb0/0x1d4
> __dwc3_gadget_start+0x25c/0x720
> kretprobe_trampoline.cfi_jt+0x0/0x8
> kretprobe_trampoline.cfi_jt+0x0/0x8
> udc_bind_to_driver+0x1d8/0x300
> usb_gadget_probe_driver+0xa8/0x1dc
> gadget_dev_desc_UDC_store+0x13c/0x188
> configfs_write_iter+0x160/0x1f4
> vfs_write+0x2d0/0x40c
> ksys_write+0x7c/0xf0
> __arm64_sys_write+0x20/0x30
> invoke_syscall+0x60/0x150
> el0_svc_common+0x8c/0xf8
> do_el0_svc+0x28/0xa0
> el0_svc+0x24/0x84
> el0t_64_sync_handler+0x88/0xec
> el0t_64_sync+0x1b4/0x1b8
> Code: aa1f03e1 aa1303e0 52800022 2a0103e8 (88e87e62)
> ---[ end trace 938847327a739172 ]---
> Kernel panic - not syncing: Oops: Fatal exception
>
> Signed-off-by: Lianqin Hu <hulianqin@vivo.com>
> ---
> v2:
> - Optimize code comments
> - Delete log printing
> ---
> drivers/usb/gadget/function/u_serial.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
> index b394105e55d6..65637d53bf02
> --- a/drivers/usb/gadget/function/u_serial.c
> +++ b/drivers/usb/gadget/function/u_serial.c
> @@ -454,6 +454,14 @@ static void gs_read_complete(struct usb_ep *ep, struct usb_request *req)
> {
> struct gs_port *port = ep->driver_data;
>
> + /* When port is NULL, return to avoid panic. */
> + if (!port)
> + return;
> +
This doesn't protect the port from going to NULL right after the above
the check. Since you mentioned gser_disconnect is making port to NULL,
add the serial_port_lock to protect port (just like its done on
gser_disconnect/suspend/resume). Something like this would do.
diff --git a/drivers/usb/gadget/function/u_serial.c
b/drivers/usb/gadget/function/u_serial.c
index f975dc03a190..a33f8cd871ac 100644
--- a/drivers/usb/gadget/function/u_serial.c
+++ b/drivers/usb/gadget/function/u_serial.c
@@ -451,10 +451,21 @@ static void gs_rx_push(struct work_struct *work)
static void gs_read_complete(struct usb_ep *ep, struct usb_request *req)
{
- struct gs_port *port = ep->driver_data;
+ struct gs_port *port;
+ unsigned long flags;
+
+ spin_lock_irqsave(&serial_port_lock, flags);
+ port = ep->driver_data;
+
+ if (!port) {
+ spin_unlock_irqrestore(&serial_port_lock, flags);
+ return;
+ }
- /* Queue all received data until the tty layer is ready for it. */
spin_lock(&port->port_lock);
+ spin_unlock(&serial_port_lock);
+
+ /* Queue all received data until the tty layer is ready for it. */
list_add_tail(&req->list, &port->read_queue);
schedule_delayed_work(&port->push, 0);
spin_unlock(&port->port_lock);
> /* Queue all received data until the tty layer is ready for it. */
> spin_lock(&port->port_lock);
> list_add_tail(&req->list, &port->read_queue);
> @@ -465,6 +473,14 @@ static void gs_write_complete(struct usb_ep *ep, struct usb_request *req)
> {
> struct gs_port *port = ep->driver_data;
>
> + /* When port is NULL, return to avoid panic. */
> + if (!port)
> + return;
> +
> spin_lock(&port->port_lock);
> list_add(&req->list, &port->write_pool);
> port->write_started--;
Same here also
Best Regards,
Prashanth K
^ permalink raw reply related [flat|nested] 4+ messages in thread
* 答复: [PATCH v2] usb: gadget: u_serial: check Null pointer in EP callback
2024-08-20 10:15 ` Prashanth K
@ 2024-08-20 10:52 ` 胡连勤
0 siblings, 0 replies; 4+ messages in thread
From: 胡连勤 @ 2024-08-20 10:52 UTC (permalink / raw)
To: Prashanth K, gregkh@linuxfoundation.org
Cc: quic_jjohnson@quicinc.com, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org, opensource.kernel,
akpm@linux-foundation.org, Michael Nazzareno Trimarchi
Hello linux community expert:
>> diff --git a/drivers/usb/gadget/function/u_serial.c
>> b/drivers/usb/gadget/function/u_serial.c
>> index b394105e55d6..65637d53bf02
>> --- a/drivers/usb/gadget/function/u_serial.c
>> +++ b/drivers/usb/gadget/function/u_serial.c
>> @@ -454,6 +454,14 @@ static void gs_read_complete(struct usb_ep *ep,
>> struct usb_request *req) {
>> struct gs_port *port = ep->driver_data;
>>
>> + /* When port is NULL, return to avoid panic. */
>> + if (!port)
>> + return;
>> +
>This doesn't protect the port from going to NULL right after the above the check. Since you mentioned gser_disconnect is making port to NULL, add the serial_port_lock to protect port (just like its done on gser_disconnect/suspend/resume). Something like this would do.
OK, it is more reasonable to modify it as follows, I will modify it again.
>diff --git a/drivers/usb/gadget/function/u_serial.c
>b/drivers/usb/gadget/function/u_serial.c
>index f975dc03a190..a33f8cd871ac 100644
>--- a/drivers/usb/gadget/function/u_serial.c
>+++ b/drivers/usb/gadget/function/u_serial.c
>@@ -451,10 +451,21 @@ static void gs_rx_push(struct work_struct *work)
>static void gs_read_complete(struct usb_ep *ep, struct usb_request *req) {
>- struct gs_port *port = ep->driver_data;
>+ struct gs_port *port;
>+ unsigned long flags;
>+
>+ spin_lock_irqsave(&serial_port_lock, flags);
>+ port = ep->driver_data;
>+
>+ if (!port) {
>+ spin_unlock_irqrestore(&serial_port_lock, flags);
>+ return;
>+ }
>- /* Queue all received data until the tty layer is ready for it. */
> spin_lock(&port->port_lock);
>+ spin_unlock(&serial_port_lock);
>+
>+ /* Queue all received data until the tty layer is ready for it.
>+ */
> list_add_tail(&req->list, &port->read_queue);
> schedule_delayed_work(&port->push, 0);
> spin_unlock(&port->port_lock);
>
>> /* Queue all received data until the tty layer is ready for it. */
>> spin_lock(&port->port_lock);
>> list_add_tail(&req->list, &port->read_queue); @@ -465,6 +473,14 @@
>> static void gs_write_complete(struct usb_ep *ep, struct usb_request
>> *req) {
>> struct gs_port *port = ep->driver_data;
>>
>> + /* When port is NULL, return to avoid panic. */
>> + if (!port)
>> + return;
>> +
>> spin_lock(&port->port_lock);
>> list_add(&req->list, &port->write_pool);
>> port->write_started--;
>Same here also
Thanks
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] usb: gadget: u_serial: check Null pointer in EP callback
2024-08-20 9:29 [PATCH v2] usb: gadget: u_serial: check Null pointer in EP callback 胡连勤
2024-08-20 10:15 ` Prashanth K
@ 2024-08-20 11:51 ` gregkh
1 sibling, 0 replies; 4+ messages in thread
From: gregkh @ 2024-08-20 11:51 UTC (permalink / raw)
To: 胡连勤
Cc: quic_prashk@quicinc.com, quic_jjohnson@quicinc.com,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
opensource.kernel, akpm@linux-foundation.org,
Michael Nazzareno Trimarchi
On Tue, Aug 20, 2024 at 09:29:05AM +0000, 胡连勤 wrote:
> From: Lianqin Hu <hulianqin@vivo.com>
>
> Added null pointer check to avoid system crash.
>
> Unable to handle kernel NULL pointer dereference at
> virtual address 00000000000001a8
> pc : gs_read_complete+0x58/0x240
> lr : usb_gadget_giveback_request+0x40/0x160
> sp : ffffffc00f1539c0
> x29: ffffffc00f1539c0 x28: ffffff8002a30000 x27: 0000000000000000
> x26: ffffff8002a30000 x25: 0000000000000000 x24: ffffff8002a30000
> x23: ffffff8002ff9a70 x22: ffffff898e7a7b00 x21: ffffff803c9af9d8
> x20: ffffff898e7a7b00 x19: 00000000000001a8 x18: ffffffc0099fd098
> x17: 0000000000001000 x16: 0000000080000000 x15: 0000000ac1200000
> x14: 0000000000000003 x13: 000000000000d5e8 x12: 0000000355c314ac
> x11: 0000000000000015 x10: 0000000000000012 x9 : 0000000000000008
> x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffffff887cd12000
> x5 : 0000000000000002 x4 : ffffffc00f9b07f0 x3 : ffffffc00f1538d0
> x2 : 0000000000000001 x1 : 0000000000000000 x0 : 00000000000001a8
> Call trace:
> gs_read_complete+0x58/0x240
> usb_gadget_giveback_request+0x40/0x160
> dwc3_remove_requests+0x170/0x484
> dwc3_ep0_out_start+0xb0/0x1d4
> __dwc3_gadget_start+0x25c/0x720
> kretprobe_trampoline.cfi_jt+0x0/0x8
> kretprobe_trampoline.cfi_jt+0x0/0x8
> udc_bind_to_driver+0x1d8/0x300
> usb_gadget_probe_driver+0xa8/0x1dc
> gadget_dev_desc_UDC_store+0x13c/0x188
> configfs_write_iter+0x160/0x1f4
> vfs_write+0x2d0/0x40c
> ksys_write+0x7c/0xf0
> __arm64_sys_write+0x20/0x30
> invoke_syscall+0x60/0x150
> el0_svc_common+0x8c/0xf8
> do_el0_svc+0x28/0xa0
> el0_svc+0x24/0x84
> el0t_64_sync_handler+0x88/0xec
> el0t_64_sync+0x1b4/0x1b8
> Code: aa1f03e1 aa1303e0 52800022 2a0103e8 (88e87e62)
> ---[ end trace 938847327a739172 ]---
> Kernel panic - not syncing: Oops: Fatal exception
>
> Signed-off-by: Lianqin Hu <hulianqin@vivo.com>
> ---
> v2:
> - Optimize code comments
> - Delete log printing
> ---
> drivers/usb/gadget/function/u_serial.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
Any specific reason you ignored my previous review comments?
^ permalink raw reply [flat|nested] 4+ messages in thread
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2024-08-20 9:29 [PATCH v2] usb: gadget: u_serial: check Null pointer in EP callback 胡连勤
2024-08-20 10:15 ` Prashanth K
2024-08-20 10:52 ` 答复: " 胡连勤
2024-08-20 11:51 ` gregkh
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