In the Linux kernel, the following vulnerability has been resolved:
ath9k: fix use-after-free in ath9k_hif_usb_rx_cb
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]
| Software | From | Fixed in |
|---|---|---|
| linux / linux_kernel | 2.6.35 | 4.14.291 |
| linux / linux_kernel | 4.15 | 4.19.256 |
| linux / linux_kernel | 4.20 | 5.4.211 |
| linux / linux_kernel | 5.5 | 5.10.137 |
| linux / linux_kernel | 5.11 | 5.15.61 |
| linux / linux_kernel | 5.16 | 5.18.18 |
| linux / linux_kernel | 5.19 | 5.19.2 |