* [PATCH][next] staging: rtl8188eu: Fix null pointer dereference on free_netdev call
@ 2021-03-24 15:21 Colin King
2021-03-24 16:11 ` Martin Kaiser
0 siblings, 1 reply; 3+ messages in thread
From: Colin King @ 2021-03-24 15:21 UTC (permalink / raw)
To: Larry Finger, Greg Kroah-Hartman, Martin Kaiser, linux-staging
Cc: kernel-janitors, linux-kernel
From: Colin Ian King <colin.king@canonical.com>
An unregister_netdev call checks if pnetdev is null, hence a later
call to free_netdev can potentially be passing a null pointer, causing
a null pointer dereference. Avoid this by adding a null pointer check
on pnetdev before calling free_netdev.
Fixes: 1665c8fdffbb ("staging: rtl8188eu: use netdev routines for private data")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
drivers/staging/rtl8188eu/os_dep/usb_intf.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/rtl8188eu/os_dep/usb_intf.c b/drivers/staging/rtl8188eu/os_dep/usb_intf.c
index 518e9feb3f46..91a3d34a1050 100644
--- a/drivers/staging/rtl8188eu/os_dep/usb_intf.c
+++ b/drivers/staging/rtl8188eu/os_dep/usb_intf.c
@@ -446,7 +446,8 @@ static void rtw_usb_if1_deinit(struct adapter *if1)
pr_debug("+r871xu_dev_remove, hw_init_completed=%d\n",
if1->hw_init_completed);
rtw_free_drv_sw(if1);
- free_netdev(pnetdev);
+ if (pnetdev)
+ free_netdev(pnetdev);
}
static int rtw_drv_init(struct usb_interface *pusb_intf, const struct usb_device_id *pdid)
--
2.30.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH][next] staging: rtl8188eu: Fix null pointer dereference on free_netdev call
2021-03-24 15:21 [PATCH][next] staging: rtl8188eu: Fix null pointer dereference on free_netdev call Colin King
@ 2021-03-24 16:11 ` Martin Kaiser
2021-03-24 16:12 ` Colin Ian King
0 siblings, 1 reply; 3+ messages in thread
From: Martin Kaiser @ 2021-03-24 16:11 UTC (permalink / raw)
To: Colin King
Cc: Larry Finger, Greg Kroah-Hartman, linux-staging, kernel-janitors,
linux-kernel
Hello Colin,
Thus wrote Colin King (colin.king@canonical.com):
> From: Colin Ian King <colin.king@canonical.com>
> An unregister_netdev call checks if pnetdev is null, hence a later
> call to free_netdev can potentially be passing a null pointer, causing
> a null pointer dereference. Avoid this by adding a null pointer check
> on pnetdev before calling free_netdev.
> Fixes: 1665c8fdffbb ("staging: rtl8188eu: use netdev routines for private data")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
> drivers/staging/rtl8188eu/os_dep/usb_intf.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
> diff --git a/drivers/staging/rtl8188eu/os_dep/usb_intf.c b/drivers/staging/rtl8188eu/os_dep/usb_intf.c
> index 518e9feb3f46..91a3d34a1050 100644
> --- a/drivers/staging/rtl8188eu/os_dep/usb_intf.c
> +++ b/drivers/staging/rtl8188eu/os_dep/usb_intf.c
> @@ -446,7 +446,8 @@ static void rtw_usb_if1_deinit(struct adapter *if1)
> pr_debug("+r871xu_dev_remove, hw_init_completed=%d\n",
> if1->hw_init_completed);
> rtw_free_drv_sw(if1);
> - free_netdev(pnetdev);
> + if (pnetdev)
> + free_netdev(pnetdev);
> }
> static int rtw_drv_init(struct usb_interface *pusb_intf, const struct usb_device_id *pdid)
> --
> 2.30.2
you're right. I removed the NULL check that was part of rtw_free_netdev.
Sorry for the mistake and thanks for your fix.
Reviewed-by: Martin Kaiser <martin@kaiser.cx>
Best regards,
Martin
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH][next] staging: rtl8188eu: Fix null pointer dereference on free_netdev call
2021-03-24 16:11 ` Martin Kaiser
@ 2021-03-24 16:12 ` Colin Ian King
0 siblings, 0 replies; 3+ messages in thread
From: Colin Ian King @ 2021-03-24 16:12 UTC (permalink / raw)
To: Martin Kaiser
Cc: Larry Finger, Greg Kroah-Hartman, linux-staging, kernel-janitors,
linux-kernel
On 24/03/2021 16:11, Martin Kaiser wrote:
> Hello Colin,
>
> Thus wrote Colin King (colin.king@canonical.com):
>
>> From: Colin Ian King <colin.king@canonical.com>
>
>> An unregister_netdev call checks if pnetdev is null, hence a later
>> call to free_netdev can potentially be passing a null pointer, causing
>> a null pointer dereference. Avoid this by adding a null pointer check
>> on pnetdev before calling free_netdev.
>
>> Fixes: 1665c8fdffbb ("staging: rtl8188eu: use netdev routines for private data")
>> Signed-off-by: Colin Ian King <colin.king@canonical.com>
>> ---
>> drivers/staging/rtl8188eu/os_dep/usb_intf.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>
>> diff --git a/drivers/staging/rtl8188eu/os_dep/usb_intf.c b/drivers/staging/rtl8188eu/os_dep/usb_intf.c
>> index 518e9feb3f46..91a3d34a1050 100644
>> --- a/drivers/staging/rtl8188eu/os_dep/usb_intf.c
>> +++ b/drivers/staging/rtl8188eu/os_dep/usb_intf.c
>> @@ -446,7 +446,8 @@ static void rtw_usb_if1_deinit(struct adapter *if1)
>> pr_debug("+r871xu_dev_remove, hw_init_completed=%d\n",
>> if1->hw_init_completed);
>> rtw_free_drv_sw(if1);
>> - free_netdev(pnetdev);
>> + if (pnetdev)
>> + free_netdev(pnetdev);
>> }
>
>> static int rtw_drv_init(struct usb_interface *pusb_intf, const struct usb_device_id *pdid)
>> --
>> 2.30.2
>
> you're right. I removed the NULL check that was part of rtw_free_netdev.
> Sorry for the mistake and thanks for your fix.
Thank static analysis :-)
>
> Reviewed-by: Martin Kaiser <martin@kaiser.cx>
>
> Best regards,
> Martin
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-03-24 15:21 [PATCH][next] staging: rtl8188eu: Fix null pointer dereference on free_netdev call Colin King
2021-03-24 16:11 ` Martin Kaiser
2021-03-24 16:12 ` Colin Ian King
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