From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: Kalle Valo <kvalo@codeaurora.org>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>
Cc: ath9k-devel@qca.qualcomm.com,
linux-wireless <linux-wireless@vger.kernel.org>,
Network Development <netdev@vger.kernel.org>
Subject: [PATCH 2/2 (RESEND)] ath9k_htc: fix NULL pointer dereference at ath9k_htc_tx_get_packet()
Date: Tue, 21 Sep 2021 22:06:26 +0900 [thread overview]
Message-ID: <77b76ac8-2bee-6444-d26c-8c30858b8daa@i-love.sakura.ne.jp> (raw)
syzbot is reporting lockdep warning at ath9k_wmi_event_tasklet() followed
by kernel panic at get_htc_epid_queue() from ath9k_htc_tx_get_packet() from
ath9k_htc_txstatus() [1], for ath9k_wmi_event_tasklet(WMI_TXSTATUS_EVENTID)
depends on spin_lock_init() from ath9k_init_priv() being already completed.
Since ath9k_wmi_event_tasklet() is set by ath9k_init_wmi() from
ath9k_htc_probe_device(), it is possible that ath9k_wmi_event_tasklet() is
called via tasklet interrupt before spin_lock_init() from ath9k_init_priv()
from ath9k_init_device() from ath9k_htc_probe_device() is called.
Let's hold ath9k_wmi_event_tasklet(WMI_TXSTATUS_EVENTID) no-op until
ath9k_tx_init() completes.
Link: https://syzkaller.appspot.com/bug?extid=31d54c60c5b254d6f75b [1]
Reported-by: syzbot <syzbot+31d54c60c5b254d6f75b@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+31d54c60c5b254d6f75b@syzkaller.appspotmail.com>
---
drivers/net/wireless/ath/ath9k/htc.h | 1 +
drivers/net/wireless/ath/ath9k/htc_drv_txrx.c | 3 +++
drivers/net/wireless/ath/ath9k/wmi.c | 3 +++
3 files changed, 7 insertions(+)
diff --git a/drivers/net/wireless/ath/ath9k/htc.h b/drivers/net/wireless/ath/ath9k/htc.h
index 4f71e962279a..6b45e63fae4b 100644
--- a/drivers/net/wireless/ath/ath9k/htc.h
+++ b/drivers/net/wireless/ath/ath9k/htc.h
@@ -306,6 +306,7 @@ struct ath9k_htc_tx {
DECLARE_BITMAP(tx_slot, MAX_TX_BUF_NUM);
struct timer_list cleanup_timer;
spinlock_t tx_lock;
+ bool initialized;
};
struct ath9k_htc_tx_ctl {
diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c
index 0d4595ee51ba..a5240a7f8c00 100644
--- a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c
@@ -813,6 +813,9 @@ int ath9k_tx_init(struct ath9k_htc_priv *priv)
skb_queue_head_init(&priv->tx.data_vi_queue);
skb_queue_head_init(&priv->tx.data_vo_queue);
skb_queue_head_init(&priv->tx.tx_failed);
+ /* Allow ath9k_wmi_event_tasklet(WMI_TXSTATUS_EVENTID) to operate. */
+ smp_wmb();
+ priv->tx.initialized = true;
return 0;
}
diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c
index fe29ad4b9023..7e17d86bf5d3 100644
--- a/drivers/net/wireless/ath/ath9k/wmi.c
+++ b/drivers/net/wireless/ath/ath9k/wmi.c
@@ -169,6 +169,9 @@ void ath9k_wmi_event_tasklet(struct tasklet_struct *t)
&wmi->drv_priv->fatal_work);
break;
case WMI_TXSTATUS_EVENTID:
+ /* Check if ath9k_tx_init() completed. */
+ if (!data_race(priv->tx.initialized))
+ break;
spin_lock_bh(&priv->tx.tx_lock);
if (priv->tx.flags & ATH9K_HTC_OP_TX_DRAIN) {
spin_unlock_bh(&priv->tx.tx_lock);
--
2.18.4
next reply other threads:[~2021-09-21 13:06 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-21 13:06 Tetsuo Handa [this message]
2021-10-02 9:29 ` Two ath9k_htc fixes Tetsuo Handa
2021-10-02 11:18 ` Kalle Valo
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