[PATCH 5.10 0/1] ath9k: fix use-after-free in ath9k_hif_usb_rx_cb

[PATCH 5.10 0/1] ath9k: fix use-after-free in ath9k_hif_usb_rx_cb

[Dragos-Marian Panait]

The following commit is needed to fix CVE-2022-1679:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0ac4827f78c7ffe8eef074bc010e7e34bc22f533

Pavel Skripkin (1):
  ath9k: fix use-after-free in ath9k_hif_usb_rx_cb

 drivers/net/wireless/ath/ath9k/htc.h          | 10 +++++-----
 drivers/net/wireless/ath/ath9k/htc_drv_init.c |  3 ++-
 2 files changed, 7 insertions(+), 6 deletions(-)


base-commit: 6eae1503ddf94b4c3581092d566b17ed12d80f20
-- 
2.37.1

[PATCH 5.10 1/1] ath9k: fix use-after-free in ath9k_hif_usb_rx_cb

[Dragos-Marian Panait]

From: Pavel Skripkin <paskripkin@gmail.com>

commit 0ac4827f78c7ffe8eef074bc010e7e34bc22f533 upstream.

Syzbot reported use-after-free Read in ath9k_hif_usb_rx_cb() [0]. The
problem was in incorrect htc_handle->drv_priv initialization.

Probable call trace which can trigger use-after-free:

ath9k_htc_probe_device()
  /* htc_handle->drv_priv = priv; */
  ath9k_htc_wait_for_target()      <--- Failed
  ieee80211_free_hw()		   <--- priv pointer is freed

<IRQ>
...
ath9k_hif_usb_rx_cb()
  ath9k_hif_usb_rx_stream()
   RX_STAT_INC()		<--- htc_handle->drv_priv access

In order to not add fancy protection for drv_priv we can move
htc_handle->drv_priv initialization at the end of the
ath9k_htc_probe_device() and add helper macro to make
all *_STAT_* macros NULL safe, since syzbot has reported related NULL
deref in that macros [1]

Link: https://syzkaller.appspot.com/bug?id=6ead44e37afb6866ac0c7dd121b4ce07cb665f60 [0]
Link: https://syzkaller.appspot.com/bug?id=b8101ffcec107c0567a0cd8acbbacec91e9ee8de [1]
Fixes: fb9987d0f748 ("ath9k_htc: Support for AR9271 chipset.")
Reported-and-tested-by: syzbot+03110230a11411024147@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+c6dde1f690b60e0b9fbe@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/d57bbedc857950659bfacac0ab48790c1eda00c8.1655145743.git.paskripkin@gmail.com
Signed-off-by: Dragos-Marian Panait <dragos.panait@windriver.com>
---
 drivers/net/wireless/ath/ath9k/htc.h          | 10 +++++-----
 drivers/net/wireless/ath/ath9k/htc_drv_init.c |  3 ++-
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/htc.h b/drivers/net/wireless/ath/ath9k/htc.h
index 6b45e63fae4b..e3d546ef71dd 100644
--- a/drivers/net/wireless/ath/ath9k/htc.h
+++ b/drivers/net/wireless/ath/ath9k/htc.h
@@ -327,11 +327,11 @@ static inline struct ath9k_htc_tx_ctl *HTC_SKB_CB(struct sk_buff *skb)
 }
 
 #ifdef CONFIG_ATH9K_HTC_DEBUGFS
-
-#define TX_STAT_INC(c) (hif_dev->htc_handle->drv_priv->debug.tx_stats.c++)
-#define TX_STAT_ADD(c, a) (hif_dev->htc_handle->drv_priv->debug.tx_stats.c += a)
-#define RX_STAT_INC(c) (hif_dev->htc_handle->drv_priv->debug.skbrx_stats.c++)
-#define RX_STAT_ADD(c, a) (hif_dev->htc_handle->drv_priv->debug.skbrx_stats.c += a)
+#define __STAT_SAFE(expr) (hif_dev->htc_handle->drv_priv ? (expr) : 0)
+#define TX_STAT_INC(c) __STAT_SAFE(hif_dev->htc_handle->drv_priv->debug.tx_stats.c++)
+#define TX_STAT_ADD(c, a) __STAT_SAFE(hif_dev->htc_handle->drv_priv->debug.tx_stats.c += a)
+#define RX_STAT_INC(c) __STAT_SAFE(hif_dev->htc_handle->drv_priv->debug.skbrx_stats.c++)
+#define RX_STAT_ADD(c, a) __STAT_SAFE(hif_dev->htc_handle->drv_priv->debug.skbrx_stats.c += a)
 #define CAB_STAT_INC   priv->debug.tx_stats.cab_queued++
 
 #define TX_QSTAT_INC(q) (priv->debug.tx_stats.queue_stats[q]++)
diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_init.c b/drivers/net/wireless/ath/ath9k/htc_drv_init.c
index ff61ae34ecdf..07ac88fb1c57 100644
--- a/drivers/net/wireless/ath/ath9k/htc_drv_init.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_init.c
@@ -944,7 +944,6 @@ int ath9k_htc_probe_device(struct htc_target *htc_handle, struct device *dev,
 	priv->hw = hw;
 	priv->htc = htc_handle;
 	priv->dev = dev;
-	htc_handle->drv_priv = priv;
 	SET_IEEE80211_DEV(hw, priv->dev);
 
 	ret = ath9k_htc_wait_for_target(priv);
@@ -965,6 +964,8 @@ int ath9k_htc_probe_device(struct htc_target *htc_handle, struct device *dev,
 	if (ret)
 		goto err_init;
 
+	htc_handle->drv_priv = priv;
+
 	return 0;
 
 err_init:
-- 
2.37.1

Re: [PATCH 5.10 0/1] ath9k: fix use-after-free in ath9k_hif_usb_rx_cb

[Greg KH]

On Fri, Aug 19, 2022 at 01:38:51PM +0300, Dragos-Marian Panait wrote:
> The following commit is needed to fix CVE-2022-1679:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0ac4827f78c7ffe8eef074bc010e7e34bc22f533
> 
> Pavel Skripkin (1):
>   ath9k: fix use-after-free in ath9k_hif_usb_rx_cb
> 
>  drivers/net/wireless/ath/ath9k/htc.h          | 10 +++++-----
>  drivers/net/wireless/ath/ath9k/htc_drv_init.c |  3 ++-
>  2 files changed, 7 insertions(+), 6 deletions(-)
> 
> 
> base-commit: 6eae1503ddf94b4c3581092d566b17ed12d80f20
> -- 
> 2.37.1
> 

This is already queued up for 5.10.  You forgot the backports to older
kernels, which is also already queued up.

thanks,

greg k-h

Re: [PATCH 5.10 0/1] ath9k: fix use-after-free in ath9k_hif_usb_rx_cb

[Dragos-Marian Panait]

Hi Greg,

On 19.08.2022 14:23, Greg KH wrote:
> [Please note: This e-mail is from an EXTERNAL e-mail address]
>
> On Fri, Aug 19, 2022 at 01:38:51PM +0300, Dragos-Marian Panait wrote:
>> The following commit is needed to fix CVE-2022-1679:
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0ac4827f78c7ffe8eef074bc010e7e34bc22f533
>>
>> Pavel Skripkin (1):
>>    ath9k: fix use-after-free in ath9k_hif_usb_rx_cb
>>
>>   drivers/net/wireless/ath/ath9k/htc.h          | 10 +++++-----
>>   drivers/net/wireless/ath/ath9k/htc_drv_init.c |  3 ++-
>>   2 files changed, 7 insertions(+), 6 deletions(-)
>>
>>
>> base-commit: 6eae1503ddf94b4c3581092d566b17ed12d80f20
>> --
>> 2.37.1
>>
> This is already queued up for 5.10.  You forgot the backports to older
> kernels, which is also already queued up.
Are you sure of this?
I can not find any patch for older kernels in the stable mailing 
list(except for 5.15, 5.18, 5.19).

Thanks,
Dragos
>
> thanks,
>
> greg k-h

Re: [PATCH 5.10 0/1] ath9k: fix use-after-free in ath9k_hif_usb_rx_cb

[Greg KH]

On Fri, Aug 19, 2022 at 03:18:26PM +0300, Dragos-Marian Panait wrote:
> Hi Greg,
> 
> On 19.08.2022 14:23, Greg KH wrote:
> > [Please note: This e-mail is from an EXTERNAL e-mail address]
> > 
> > On Fri, Aug 19, 2022 at 01:38:51PM +0300, Dragos-Marian Panait wrote:
> > > The following commit is needed to fix CVE-2022-1679:
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0ac4827f78c7ffe8eef074bc010e7e34bc22f533
> > > 
> > > Pavel Skripkin (1):
> > >    ath9k: fix use-after-free in ath9k_hif_usb_rx_cb
> > > 
> > >   drivers/net/wireless/ath/ath9k/htc.h          | 10 +++++-----
> > >   drivers/net/wireless/ath/ath9k/htc_drv_init.c |  3 ++-
> > >   2 files changed, 7 insertions(+), 6 deletions(-)
> > > 
> > > 
> > > base-commit: 6eae1503ddf94b4c3581092d566b17ed12d80f20
> > > --
> > > 2.37.1
> > > 
> > This is already queued up for 5.10.  You forgot the backports to older
> > kernels, which is also already queued up.
> Are you sure of this?
> I can not find any patch for older kernels in the stable mailing list(except
> for 5.15, 5.18, 5.19).

Look in the stable-queue.git tree on git.kernel.org.

thanks,

greg k-h