From 24355fcb0d4cbcb6ddda262596558e8cfba70f11 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Fri, 26 Jan 2024 15:02:17 +0100 Subject: [PATCH] wifi: ath9k: delay all of ath9k_wmi_event_tasklet() until init is complete MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The ath9k_wmi_event_tasklet() used in ath9k_htc assumes that all the data structures have been fully initialised by the time it runs. However, because of the order in which things are initialised, this is not guaranteed to be the case, because the device is exposed to the USB subsystem before the ath9k driver initialisation is completed. We already committed a partial fix for this in commit: 8b3046abc99e ("ath9k_htc: fix NULL pointer dereference at ath9k_htc_tx_get_packet()") However, that commit only aborted the WMI_TXSTATUS_EVENTID command in the event tasklet, pairing it with an "initialisation complete" bit in the TX struct. It seems syzbot managed to trigger the race for one of the other commands as well, so let's just move the existing synchronisation bit to cover the whole tasklet (setting it at the end of ath9k_htc_probe_device() instead of inside ath9k_tx_init()). Link: https://lore.kernel.org/r/ed1d2c66-1193-4c81-9542-d514c29ba8b8.bugreport@ubisectech.com Fixes: 8b3046abc99e ("ath9k_htc: fix NULL pointer dereference at ath9k_htc_tx_get_packet()") Reported-by: Ubisectech Sirius Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Kalle Valo Link: https://msgid.link/20240126140218.1033443-1-toke@toke.dk --- drivers/net/wireless/ath/ath9k/htc.h | 2 +- drivers/net/wireless/ath/ath9k/htc_drv_init.c | 4 ++++ drivers/net/wireless/ath/ath9k/htc_drv_txrx.c | 4 ---- drivers/net/wireless/ath/ath9k/wmi.c | 10 ++++++---- 4 files changed, 11 insertions(+), 9 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/htc.h b/drivers/net/wireless/ath/ath9k/htc.h index 237f4ec2cffd..6c33e898b300 100644 --- a/drivers/net/wireless/ath/ath9k/htc.h +++ b/drivers/net/wireless/ath/ath9k/htc.h @@ -306,7 +306,6 @@ 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 { @@ -515,6 +514,7 @@ struct ath9k_htc_priv { unsigned long ps_usecount; bool ps_enabled; bool ps_idle; + bool initialized; #ifdef CONFIG_MAC80211_LEDS enum led_brightness brightness; diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_init.c b/drivers/net/wireless/ath/ath9k/htc_drv_init.c index 0aa5bdeb44a1..3633f9eb2c55 100644 --- a/drivers/net/wireless/ath/ath9k/htc_drv_init.c +++ b/drivers/net/wireless/ath/ath9k/htc_drv_init.c @@ -966,6 +966,10 @@ int ath9k_htc_probe_device(struct htc_target *htc_handle, struct device *dev, htc_handle->drv_priv = priv; + /* Allow ath9k_wmi_event_tasklet() to operate. */ + smp_wmb(); + priv->initialized = true; + return 0; err_init: diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c index efcaeccb055a..ce9c04e418b8 100644 --- a/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c +++ b/drivers/net/wireless/ath/ath9k/htc_drv_txrx.c @@ -815,10 +815,6 @@ int ath9k_tx_init(struct ath9k_htc_priv *priv) 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 1476b42b52a9..805ad31edba2 100644 --- a/drivers/net/wireless/ath/ath9k/wmi.c +++ b/drivers/net/wireless/ath/ath9k/wmi.c @@ -155,6 +155,12 @@ void ath9k_wmi_event_tasklet(struct tasklet_struct *t) } spin_unlock_irqrestore(&wmi->wmi_lock, flags); + /* Check if ath9k_htc_probe_device() completed. */ + if (!data_race(priv->initialized)) { + kfree_skb(skb); + continue; + } + hdr = (struct wmi_cmd_hdr *) skb->data; cmd_id = be16_to_cpu(hdr->command_id); wmi_event = skb_pull(skb, sizeof(struct wmi_cmd_hdr)); @@ -169,10 +175,6 @@ 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);