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| author | Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> | 2021-09-21 16:06:23 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-01-27 13:04:45 +0300 |
| commit | 6eedec710840104c190f51d45a57daf34216b90e (patch) | |
| tree | b80ee5c5938c820664fdd12545836dc567e751aa | |
| parent | 243ab93501e6fc13d376673e26ab240a82bbcffa (diff) | |
| download | linux-6eedec710840104c190f51d45a57daf34216b90e.tar.xz | |
ath9k_htc: fix NULL pointer dereference at ath9k_htc_rxep()
[ Upstream commit b0ec7e55fce65f125bd1d7f02e2dc4de62abee34 ]
syzbot is reporting lockdep warning followed by kernel panic at
ath9k_htc_rxep() [1], for ath9k_htc_rxep() depends on ath9k_rx_init()
being already completed.
Since ath9k_htc_rxep() is set by ath9k_htc_connect_svc(WMI_BEACON_SVC)
from ath9k_init_htc_services(), it is possible that ath9k_htc_rxep() is
called via timer interrupt before ath9k_rx_init() from ath9k_init_device()
is called.
Since we can't call ath9k_init_device() before ath9k_init_htc_services(),
let's hold ath9k_htc_rxep() no-op until ath9k_rx_init() completes.
Link: https://syzkaller.appspot.com/bug?extid=4d2d56175b934b9a7bf9 [1]
Reported-by: syzbot <syzbot+4d2d56175b934b9a7bf9@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+4d2d56175b934b9a7bf9@syzkaller.appspotmail.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/2b88f416-b2cb-7a18-d688-951e6dc3fe92@i-love.sakura.ne.jp
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/net/wireless/ath/ath9k/htc.h | 1 | ||||
| -rw-r--r-- | drivers/net/wireless/ath/ath9k/htc_drv_txrx.c | 8 |
2 files changed, 9 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/ath9k/htc.h b/drivers/net/wireless/ath/ath9k/htc.h index 0a1634238e67..4f71e962279a 100644 --- a/drivers/net/wireless/ath/ath9k/htc.h +++ b/drivers/net/wireless/ath/ath9k/htc.h @@ -281,6 +281,7 @@ struct ath9k_htc_rxbuf { struct ath9k_htc_rx { struct list_head rxbuf; spinlock_t rxbuflock; + bool initialized; }; #define ATH9K_HTC_TX_CLEANUP_INTERVAL 50 /* ms */ diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c index 8e69e8989f6d..e7a21eaf3a68 100644 --- a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c +++ b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c @@ -1130,6 +1130,10 @@ void ath9k_htc_rxep(void *drv_priv, struct sk_buff *skb, struct ath9k_htc_rxbuf *rxbuf = NULL, *tmp_buf = NULL; unsigned long flags; + /* Check if ath9k_rx_init() completed. */ + if (!data_race(priv->rx.initialized)) + goto err; + spin_lock_irqsave(&priv->rx.rxbuflock, flags); list_for_each_entry(tmp_buf, &priv->rx.rxbuf, list) { if (!tmp_buf->in_process) { @@ -1185,6 +1189,10 @@ int ath9k_rx_init(struct ath9k_htc_priv *priv) list_add_tail(&rxbuf->list, &priv->rx.rxbuf); } + /* Allow ath9k_htc_rxep() to operate. */ + smp_wmb(); + priv->rx.initialized = true; + return 0; err: |