From: Pavel Skripkin <paskripkin@gmail.com>
To: toke@toke.dk, kvalo@kernel.org, davem@davemloft.net,
kuba@kernel.org, pabeni@redhat.com
Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org,
Pavel Skripkin <paskripkin@gmail.com>,
syzbot+03110230a11411024147@syzkaller.appspotmail.com,
syzbot+c6dde1f690b60e0b9fbe@syzkaller.appspotmail.com
Subject: [PATCH v4 1/2] ath9k: fix use-after-free in ath9k_hif_usb_rx_cb
Date: Sat, 14 May 2022 21:44:53 +0300 [thread overview]
Message-ID: <f158608e209a6f45c76ec856474a796df93d9dcf.1652553719.git.paskripkin@gmail.com> (raw)
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 save, 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>
---
Changes since v3:
- s/SAVE/SAFE/
- Added links to syzkaller reports
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..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:
--
2.36.0
next reply other threads:[~2022-05-14 18:45 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-14 18:44 Pavel Skripkin [this message]
2022-05-14 18:45 ` [PATCH v4 2/2] ath9k: htc: clean up statistics macros Pavel Skripkin
2022-05-17 10:14 ` Toke Høiland-Jørgensen
2022-05-17 10:13 ` [PATCH v4 1/2] ath9k: fix use-after-free in ath9k_hif_usb_rx_cb Toke Høiland-Jørgensen
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