diff mbox series

[net,3/5] wifi: rtlwifi: wait for firmware loading before releasing memory

Message ID 20241107133322.855112-4-cascardo@igalia.com (mailing list archive)
State New
Delegated to: Ping-Ke Shih
Headers show
Series wifi: rtlwifi: usb probe error path fixes | expand

Commit Message

Thadeu Lima de Souza Cascardo Nov. 7, 2024, 1:33 p.m. UTC
At probe error path, the firmware loading work may have already been
queued. In such a case, it will try to access memory allocated by the probe
function, which is about to be released. In such paths, wait for the
firmware worker to finish before releasing memory.

Fixes: a7f7c15e945a ("rtlwifi: rtl8192cu: Free ieee80211_hw if probing fails")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
---
 drivers/net/wireless/realtek/rtlwifi/usb.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Ping-Ke Shih Nov. 8, 2024, 2:12 a.m. UTC | #1
Thadeu Lima de Souza Cascardo <cascardo@igalia.com> wrote:
> At probe error path, the firmware loading work may have already been
> queued. In such a case, it will try to access memory allocated by the probe
> function, which is about to be released. In such paths, wait for the
> firmware worker to finish before releasing memory.
> 
> Fixes: a7f7c15e945a ("rtlwifi: rtl8192cu: Free ieee80211_hw if probing fails")
> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
> ---
>  drivers/net/wireless/realtek/rtlwifi/usb.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/realtek/rtlwifi/usb.c b/drivers/net/wireless/realtek/rtlwifi/usb.c
> index c3aa0cd9ff21..c27b116ccdff 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/usb.c
> +++ b/drivers/net/wireless/realtek/rtlwifi/usb.c
> @@ -1028,13 +1028,15 @@ int rtl_usb_probe(struct usb_interface *intf,
>         err = ieee80211_register_hw(hw);
>         if (err) {
>                 pr_err("Can't register mac80211 hw.\n");
> -               goto error_out;
> +               goto error_init_vars;
>         }
>         rtlpriv->mac80211.mac80211_registered = 1;
> 
>         set_bit(RTL_STATUS_INTERFACE_START, &rtlpriv->status);
>         return 0;
> 
> +error_init_vars:
> +       wait_for_completion(&rtlpriv->firmware_loading_complete);

The firmware request is trigged by rtlpriv->cfg->ops->init_sw_vars(hw), and
here is wait for filling rtlpriv->rtlhal.pfirmware and
rtlpriv->rtlhal.wowlan_firmware.
 
The rtlpriv->cfg->ops->deinit_sw_vars(hw) is to free firmware. Shouldn't we
call it here? Also shouldn't PCI need this?

>  error_out:
>         rtl_deinit_core(hw);
>  error_out2:
> --
> 2.34.1
Thadeu Lima de Souza Cascardo Nov. 8, 2024, 11:05 a.m. UTC | #2
On Fri, Nov 08, 2024 at 02:12:24AM +0000, Ping-Ke Shih wrote:
> Thadeu Lima de Souza Cascardo <cascardo@igalia.com> wrote:
> > At probe error path, the firmware loading work may have already been
> > queued. In such a case, it will try to access memory allocated by the probe
> > function, which is about to be released. In such paths, wait for the
> > firmware worker to finish before releasing memory.
> > 
> > Fixes: a7f7c15e945a ("rtlwifi: rtl8192cu: Free ieee80211_hw if probing fails")
> > Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
> > ---
> >  drivers/net/wireless/realtek/rtlwifi/usb.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/net/wireless/realtek/rtlwifi/usb.c b/drivers/net/wireless/realtek/rtlwifi/usb.c
> > index c3aa0cd9ff21..c27b116ccdff 100644
> > --- a/drivers/net/wireless/realtek/rtlwifi/usb.c
> > +++ b/drivers/net/wireless/realtek/rtlwifi/usb.c
> > @@ -1028,13 +1028,15 @@ int rtl_usb_probe(struct usb_interface *intf,
> >         err = ieee80211_register_hw(hw);
> >         if (err) {
> >                 pr_err("Can't register mac80211 hw.\n");
> > -               goto error_out;
> > +               goto error_init_vars;
> >         }
> >         rtlpriv->mac80211.mac80211_registered = 1;
> > 
> >         set_bit(RTL_STATUS_INTERFACE_START, &rtlpriv->status);
> >         return 0;
> > 
> > +error_init_vars:
> > +       wait_for_completion(&rtlpriv->firmware_loading_complete);
> 
> The firmware request is trigged by rtlpriv->cfg->ops->init_sw_vars(hw), and
> here is wait for filling rtlpriv->rtlhal.pfirmware and
> rtlpriv->rtlhal.wowlan_firmware.
>  
> The rtlpriv->cfg->ops->deinit_sw_vars(hw) is to free firmware. Shouldn't we
> call it here? Also shouldn't PCI need this?
> 

About PCI, as I was testing with a USB emulator, I couldn't test it, though
I found a few fixes that it would need as well. I can send a patchset for
the PCI fixes, though I won't be able to test them.

As for merging the following patch with this one, it would make sense. But
I found out the memory leak after coming up with this fix. And instead of
explaining two bugs (one UAF and one memory leak) in the same commit, I
thought it more simple to have two commits. Besides, given the Fixes line I
came up with for each one of them, they would apply to different trees.

Cascardo.

> >  error_out:
> >         rtl_deinit_core(hw);
> >  error_out2:
> > --
> > 2.34.1
>
diff mbox series

Patch

diff --git a/drivers/net/wireless/realtek/rtlwifi/usb.c b/drivers/net/wireless/realtek/rtlwifi/usb.c
index c3aa0cd9ff21..c27b116ccdff 100644
--- a/drivers/net/wireless/realtek/rtlwifi/usb.c
+++ b/drivers/net/wireless/realtek/rtlwifi/usb.c
@@ -1028,13 +1028,15 @@  int rtl_usb_probe(struct usb_interface *intf,
 	err = ieee80211_register_hw(hw);
 	if (err) {
 		pr_err("Can't register mac80211 hw.\n");
-		goto error_out;
+		goto error_init_vars;
 	}
 	rtlpriv->mac80211.mac80211_registered = 1;
 
 	set_bit(RTL_STATUS_INTERFACE_START, &rtlpriv->status);
 	return 0;
 
+error_init_vars:
+	wait_for_completion(&rtlpriv->firmware_loading_complete);
 error_out:
 	rtl_deinit_core(hw);
 error_out2: