Re: [PATCH RESEND] net: ath9k: fix use-after-free in ath9k_hif_usb_rx_cb

On 9/22/21 19:42, Pavel Skripkin wrote:

Syzbot reported use-after-free Read in ath9k_hif_usb_rx_cb(). 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 save.

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 <redacted>
---

Why resend?
	No activity on this patch since 8/6/21, Kalle Valo has asked around,
	for review and no one claimed it.

Resend changes:
	1. Rebased on top of v5.15-rc2
	2. Removed clean ups for macros
	3. Added 1 more syzbot tag, since this patch has passed 2 syzbot
	tests

Hi, ath9k maintainers!

Does this patch need any further work? I can't see any comments on it since 8/6/21 and I can't see it on wireless patchwork.

If this bug is already fixed and I've overlooked a fix commit, please, let me know. As I see syzbot hits this bug really often [1]

Thanks


[1] https://syzkaller.appspot.com/bug?id=6ead44e37afb6866ac0c7dd121b4ce07cb665f60




With regards,
Pavel Skripkin