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* [PATCH v3 1/2] ath9k: fix use-after-free in ath9k_hif_usb_rx_cb
@ 2022-02-07 20:24 Pavel Skripkin
  2022-02-07 20:24 ` [PATCH v3 2/2] ath9k: htc: clean up *STAT_* macros Pavel Skripkin
                   ` (3 more replies)
  0 siblings, 4 replies; 19+ messages in thread
From: Pavel Skripkin @ 2022-02-07 20:24 UTC (permalink / raw)
  To: ath9k-devel, kvalo, davem, kuba, toke, linville
  Cc: linux-wireless, netdev, linux-kernel, Pavel Skripkin,
	syzbot+03110230a11411024147, syzbot+c6dde1f690b60e0b9fbe

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 <paskripkin@gmail.com>
---

Changes since v2:
	- My send-email script forgot, that mailing lists exist.
	  Added back all related lists

Changes since v1:
	- Removed clean-ups and moved them to 2/2

---
 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..141642e5e00d 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_SAVE(expr) (hif_dev->htc_handle->drv_priv ? (expr) : 0)
+#define TX_STAT_INC(c) __STAT_SAVE(hif_dev->htc_handle->drv_priv->debug.tx_stats.c++)
+#define TX_STAT_ADD(c, a) __STAT_SAVE(hif_dev->htc_handle->drv_priv->debug.tx_stats.c += a)
+#define RX_STAT_INC(c) __STAT_SAVE(hif_dev->htc_handle->drv_priv->debug.skbrx_stats.c++)
+#define RX_STAT_ADD(c, a) __STAT_SAVE(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:
-- 
2.34.1


^ permalink raw reply	[flat|nested] 19+ messages in thread

end of thread, other threads:[~2022-05-12 16:09 UTC | newest]

Thread overview: 19+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-02-07 20:24 [PATCH v3 1/2] ath9k: fix use-after-free in ath9k_hif_usb_rx_cb Pavel Skripkin
2022-02-07 20:24 ` [PATCH v3 2/2] ath9k: htc: clean up *STAT_* macros Pavel Skripkin
2022-02-07 21:24   ` Jeff Johnson
2022-02-08 15:32     ` Toke Høiland-Jørgensen
2022-02-08 15:49       ` Pavel Skripkin
2022-02-08 14:47 ` [PATCH v3 1/2] ath9k: fix use-after-free in ath9k_hif_usb_rx_cb Toke Høiland-Jørgensen
2022-02-08 15:48   ` Pavel Skripkin
2022-05-02  6:10     ` Tetsuo Handa
2022-05-05 19:09       ` Pavel Skripkin
2022-05-05 23:31         ` Tetsuo Handa
2022-05-10 19:26           ` Pavel Skripkin
2022-05-11  4:50             ` Kalle Valo
2022-05-11  9:53               ` Toke Høiland-Jørgensen
2022-05-11  9:59                 ` Kalle Valo
2022-05-12 12:49 ` Toke Høiland-Jørgensen
2022-05-12 12:55   ` Pavel Skripkin
2022-05-12 13:48     ` Toke Høiland-Jørgensen
2022-05-12 16:05 ` Jeff Johnson
2022-05-12 16:09   ` Pavel Skripkin

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