Kmemleak shows the following leak arising from routine in the usb
probe routine:
unreferenced object 0xffff895cb29bba00 (size 512):
comm "(udev-worker)", pid 534, jiffies 4294903932 (age 102751.088s)
hex dump (first 32 bytes):
77 30 30 30 00 00 00 00 02 2f 2d 2b 30 00 00 00 w000...../-+0...
02 00 2a 28 00 00 00 00 ff 55 ff ff ff 00 00 00 ..*(.....U......
backtrace:
[<ffffffff9265fa36>] kmalloc_trace+0x26/0x90
[<ffffffffc17eec41>] rtw_usb_probe+0x2f1/0x680 [rtw_usb]
[<ffffffffc03e19fd>] usb_probe_interface+0xdd/0x2e0 [usbcore]
[<ffffffff92b4f2fe>] really_probe+0x18e/0x3d0
[<ffffffff92b4f5b8>] __driver_probe_device+0x78/0x160
[<ffffffff92b4f6bf>] driver_probe_device+0x1f/0x90
[<ffffffff92b4f8df>] __driver_attach+0xbf/0x1b0
[<ffffffff92b4d350>] bus_for_each_dev+0x70/0xc0
[<ffffffff92b4e51e>] bus_add_driver+0x10e/0x210
[<ffffffff92b50935>] driver_register+0x55/0xf0
[<ffffffffc03e0708>] usb_register_driver+0x88/0x140 [usbcore]
[<ffffffff92401153>] do_one_initcall+0x43/0x210
[<ffffffff9254f42a>] do_init_module+0x4a/0x200
[<ffffffff92551d1c>] __do_sys_finit_module+0xac/0x120
[<ffffffff92ee6626>] do_syscall_64+0x56/0x80
[<ffffffff9300006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
The leak was verified to be real by unloading the driver, which resulted
in a dangling pointer to the allocation.
The allocated memory is freed in rtw_usb_disconnect().
Signed-off-by: Larry Finger <[email protected]>
Cc: Sascha Hauer <[email protected]>
Cc: Ping-Ke Shih <[email protected]>
---
drivers/net/wireless/realtek/rtw88/usb.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/net/wireless/realtek/rtw88/usb.c b/drivers/net/wireless/realtek/rtw88/usb.c
index 68e1b782d199..d28493a8f16c 100644
--- a/drivers/net/wireless/realtek/rtw88/usb.c
+++ b/drivers/net/wireless/realtek/rtw88/usb.c
@@ -882,6 +882,7 @@ void rtw_usb_disconnect(struct usb_interface *intf)
rtw_unregister_hw(rtwdev, hw);
rtw_usb_deinit_tx(rtwdev);
rtw_usb_deinit_rx(rtwdev);
+ kfree(rtwusb->usb_data);
if (rtwusb->udev->state != USB_STATE_NOTATTACHED)
usb_reset_device(rtwusb->udev);
--
2.40.0
> -----Original Message-----
> From: Larry Finger <[email protected]> On Behalf Of Larry Finger
> Sent: Saturday, April 15, 2023 9:14 AM
> To: Kalle Valo <[email protected]>
> Cc: Johannes Berg <[email protected]>; [email protected]; Larry Finger
> <[email protected]>; Sascha Hauer <[email protected]>; Ping-Ke Shih <[email protected]>
> Subject: [PATCH] wifi: rtw88: Fix memory leak in rtw88_usb
>
> Kmemleak shows the following leak arising from routine in the usb
> probe routine:
>
> unreferenced object 0xffff895cb29bba00 (size 512):
> comm "(udev-worker)", pid 534, jiffies 4294903932 (age 102751.088s)
> hex dump (first 32 bytes):
> 77 30 30 30 00 00 00 00 02 2f 2d 2b 30 00 00 00 w000...../-+0...
> 02 00 2a 28 00 00 00 00 ff 55 ff ff ff 00 00 00 ..*(.....U......
> backtrace:
> [<ffffffff9265fa36>] kmalloc_trace+0x26/0x90
> [<ffffffffc17eec41>] rtw_usb_probe+0x2f1/0x680 [rtw_usb]
> [<ffffffffc03e19fd>] usb_probe_interface+0xdd/0x2e0 [usbcore]
> [<ffffffff92b4f2fe>] really_probe+0x18e/0x3d0
> [<ffffffff92b4f5b8>] __driver_probe_device+0x78/0x160
> [<ffffffff92b4f6bf>] driver_probe_device+0x1f/0x90
> [<ffffffff92b4f8df>] __driver_attach+0xbf/0x1b0
> [<ffffffff92b4d350>] bus_for_each_dev+0x70/0xc0
> [<ffffffff92b4e51e>] bus_add_driver+0x10e/0x210
> [<ffffffff92b50935>] driver_register+0x55/0xf0
> [<ffffffffc03e0708>] usb_register_driver+0x88/0x140 [usbcore]
> [<ffffffff92401153>] do_one_initcall+0x43/0x210
> [<ffffffff9254f42a>] do_init_module+0x4a/0x200
> [<ffffffff92551d1c>] __do_sys_finit_module+0xac/0x120
> [<ffffffff92ee6626>] do_syscall_64+0x56/0x80
> [<ffffffff9300006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
>
> The leak was verified to be real by unloading the driver, which resulted
> in a dangling pointer to the allocation.
>
> The allocated memory is freed in rtw_usb_disconnect().
>
> Signed-off-by: Larry Finger <[email protected]>
> Cc: Sascha Hauer <[email protected]>
> Cc: Ping-Ke Shih <[email protected]>
> ---
> drivers/net/wireless/realtek/rtw88/usb.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/wireless/realtek/rtw88/usb.c b/drivers/net/wireless/realtek/rtw88/usb.c
> index 68e1b782d199..d28493a8f16c 100644
> --- a/drivers/net/wireless/realtek/rtw88/usb.c
> +++ b/drivers/net/wireless/realtek/rtw88/usb.c
> @@ -882,6 +882,7 @@ void rtw_usb_disconnect(struct usb_interface *intf)
> rtw_unregister_hw(rtwdev, hw);
> rtw_usb_deinit_tx(rtwdev);
> rtw_usb_deinit_rx(rtwdev);
> + kfree(rtwusb->usb_data);
I suggest to do this in rtw_usb_intf_deinit() instead, because rtwusb->usb_data is
allocated by rtw_usb_intf_init(). Not only make the code symmetric also can handle
error cases properly of rtw_usb_probe().
Ping-Ke
On 4/17/23 01:08, Ping-Ke Shih wrote:
>
>
>> -----Original Message-----
>> From: Larry Finger <[email protected]> On Behalf Of Larry Finger
>> Sent: Saturday, April 15, 2023 9:14 AM
>> To: Kalle Valo <[email protected]>
>> Cc: Johannes Berg <[email protected]>; [email protected]; Larry Finger
>> <[email protected]>; Sascha Hauer <[email protected]>; Ping-Ke Shih <[email protected]>
>> Subject: [PATCH] wifi: rtw88: Fix memory leak in rtw88_usb
>>
>> Kmemleak shows the following leak arising from routine in the usb
>> probe routine:
>>
>> unreferenced object 0xffff895cb29bba00 (size 512):
>> comm "(udev-worker)", pid 534, jiffies 4294903932 (age 102751.088s)
>> hex dump (first 32 bytes):
>> 77 30 30 30 00 00 00 00 02 2f 2d 2b 30 00 00 00 w000...../-+0...
>> 02 00 2a 28 00 00 00 00 ff 55 ff ff ff 00 00 00 ..*(.....U......
>> backtrace:
>> [<ffffffff9265fa36>] kmalloc_trace+0x26/0x90
>> [<ffffffffc17eec41>] rtw_usb_probe+0x2f1/0x680 [rtw_usb]
>> [<ffffffffc03e19fd>] usb_probe_interface+0xdd/0x2e0 [usbcore]
>> [<ffffffff92b4f2fe>] really_probe+0x18e/0x3d0
>> [<ffffffff92b4f5b8>] __driver_probe_device+0x78/0x160
>> [<ffffffff92b4f6bf>] driver_probe_device+0x1f/0x90
>> [<ffffffff92b4f8df>] __driver_attach+0xbf/0x1b0
>> [<ffffffff92b4d350>] bus_for_each_dev+0x70/0xc0
>> [<ffffffff92b4e51e>] bus_add_driver+0x10e/0x210
>> [<ffffffff92b50935>] driver_register+0x55/0xf0
>> [<ffffffffc03e0708>] usb_register_driver+0x88/0x140 [usbcore]
>> [<ffffffff92401153>] do_one_initcall+0x43/0x210
>> [<ffffffff9254f42a>] do_init_module+0x4a/0x200
>> [<ffffffff92551d1c>] __do_sys_finit_module+0xac/0x120
>> [<ffffffff92ee6626>] do_syscall_64+0x56/0x80
>> [<ffffffff9300006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
>>
>> The leak was verified to be real by unloading the driver, which resulted
>> in a dangling pointer to the allocation.
>>
>> The allocated memory is freed in rtw_usb_disconnect().
>>
>> Signed-off-by: Larry Finger <[email protected]>
>> Cc: Sascha Hauer <[email protected]>
>> Cc: Ping-Ke Shih <[email protected]>
>> ---
>> drivers/net/wireless/realtek/rtw88/usb.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/net/wireless/realtek/rtw88/usb.c b/drivers/net/wireless/realtek/rtw88/usb.c
>> index 68e1b782d199..d28493a8f16c 100644
>> --- a/drivers/net/wireless/realtek/rtw88/usb.c
>> +++ b/drivers/net/wireless/realtek/rtw88/usb.c
>> @@ -882,6 +882,7 @@ void rtw_usb_disconnect(struct usb_interface *intf)
>> rtw_unregister_hw(rtwdev, hw);
>> rtw_usb_deinit_tx(rtwdev);
>> rtw_usb_deinit_rx(rtwdev);
>> + kfree(rtwusb->usb_data);
>
> I suggest to do this in rtw_usb_intf_deinit() instead, because rtwusb->usb_data is
> allocated by rtw_usb_intf_init(). Not only make the code symmetric also can handle
> error cases properly of rtw_usb_probe().
Ping-Ke,
Thanks for the suggestion. I chose my location because the allocation was just
before the call to rtw_usb_init_tx(), thus the free went after
rtw_usb_deinit_tx(), but I see your point. I will submit v2.
Larry