APPLIED [OEM-5.14/OEM-5.17] Re: [SRU Bionic/Focal/Impish/OEM-5.14/Jammy/OEM-5.17] UBUNTU: SAUCE: ath9k: fix use-after-free in ath9k_hif_usb_rx_cb

[Timo Aaltonen]

Thadeu Lima de Souza Cascardo kirjoitti 28.6.2022 klo 15.11:
> From: Pavel Skripkin <paskripkin at gmail.com>
> 
> 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 at syzkaller.appspotmail.com
> Reported-and-tested-by: syzbot+c6dde1f690b60e0b9fbe at syzkaller.appspotmail.com
> Signed-off-by: Pavel Skripkin <paskripkin at gmail.com>
> Acked-by: Toke Høiland-Jørgensen <toke at toke.dk>
> Signed-off-by: Kalle Valo <quic_kvalo at quicinc.com>
> Link: https://lore.kernel.org/r/d57bbedc857950659bfacac0ab48790c1eda00c8.1655145743.git.paskripkin@gmail.com
> (cherry picked from commit 0ac4827f78c7ffe8eef074bc010e7e34bc22f533 ath.git)
> CVE-2022-1679
> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo at canonical.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 16dff4b89a86..d66d3c9299fb 100644
> --- a/drivers/net/wireless/ath/ath9k/htc.h
> +++ b/drivers/net/wireless/ath/ath9k/htc.h
> @@ -325,11 +325,11 @@ 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 3932e3d14f3d..2cc2f53b825a 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:

applied to oem kernels, thanks

-- 
t