* [PATCH rtw v3 1/5] wifi: rtw89: fix use-after-free in rtw89_core_tx_kick_off_and_wait()
[not found] <20250828211245.178843-1-pchelkin@ispras.ru>
@ 2025-08-28 21:11 ` Fedor Pchelkin
2025-08-29 7:42 ` Zong-Zhe Yang
2025-08-28 21:11 ` [PATCH rtw v3 2/5] wifi: rtw89: fix tx_wait initialization race Fedor Pchelkin
1 sibling, 1 reply; 4+ messages in thread
From: Fedor Pchelkin @ 2025-08-28 21:11 UTC (permalink / raw)
To: Ping-Ke Shih, Zong-Zhe Yang, Bitterblue Smith
Cc: Fedor Pchelkin, Po-Hao Huang, linux-wireless, linux-kernel,
lvc-project, stable
There is a bug observed when rtw89_core_tx_kick_off_and_wait() tries to
access already freed skb_data:
BUG: KFENCE: use-after-free write in rtw89_core_tx_kick_off_and_wait drivers/net/wireless/realtek/rtw89/core.c:1110
CPU: 6 UID: 0 PID: 41377 Comm: kworker/u64:24 Not tainted 6.17.0-rc1+ #1 PREEMPT(lazy)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS edk2-20250523-14.fc42 05/23/2025
Workqueue: events_unbound cfg80211_wiphy_work [cfg80211]
Use-after-free write at 0x0000000020309d9d (in kfence-#251):
rtw89_core_tx_kick_off_and_wait drivers/net/wireless/realtek/rtw89/core.c:1110
rtw89_core_scan_complete drivers/net/wireless/realtek/rtw89/core.c:5338
rtw89_hw_scan_complete_cb drivers/net/wireless/realtek/rtw89/fw.c:7979
rtw89_chanctx_proceed_cb drivers/net/wireless/realtek/rtw89/chan.c:3165
rtw89_chanctx_proceed drivers/net/wireless/realtek/rtw89/chan.h:141
rtw89_hw_scan_complete drivers/net/wireless/realtek/rtw89/fw.c:8012
rtw89_mac_c2h_scanofld_rsp drivers/net/wireless/realtek/rtw89/mac.c:5059
rtw89_fw_c2h_work drivers/net/wireless/realtek/rtw89/fw.c:6758
process_one_work kernel/workqueue.c:3241
worker_thread kernel/workqueue.c:3400
kthread kernel/kthread.c:463
ret_from_fork arch/x86/kernel/process.c:154
ret_from_fork_asm arch/x86/entry/entry_64.S:258
kfence-#251: 0x0000000056e2393d-0x000000009943cb62, size=232, cache=skbuff_head_cache
allocated by task 41377 on cpu 6 at 77869.159548s (0.009551s ago):
__alloc_skb net/core/skbuff.c:659
__netdev_alloc_skb net/core/skbuff.c:734
ieee80211_nullfunc_get net/mac80211/tx.c:5844
rtw89_core_send_nullfunc drivers/net/wireless/realtek/rtw89/core.c:3431
rtw89_core_scan_complete drivers/net/wireless/realtek/rtw89/core.c:5338
rtw89_hw_scan_complete_cb drivers/net/wireless/realtek/rtw89/fw.c:7979
rtw89_chanctx_proceed_cb drivers/net/wireless/realtek/rtw89/chan.c:3165
rtw89_chanctx_proceed drivers/net/wireless/realtek/rtw89/chan.c:3194
rtw89_hw_scan_complete drivers/net/wireless/realtek/rtw89/fw.c:8012
rtw89_mac_c2h_scanofld_rsp drivers/net/wireless/realtek/rtw89/mac.c:5059
rtw89_fw_c2h_work drivers/net/wireless/realtek/rtw89/fw.c:6758
process_one_work kernel/workqueue.c:3241
worker_thread kernel/workqueue.c:3400
kthread kernel/kthread.c:463
ret_from_fork arch/x86/kernel/process.c:154
ret_from_fork_asm arch/x86/entry/entry_64.S:258
freed by task 1045 on cpu 9 at 77869.168393s (0.001557s ago):
ieee80211_tx_status_skb net/mac80211/status.c:1117
rtw89_pci_release_txwd_skb drivers/net/wireless/realtek/rtw89/pci.c:564
rtw89_pci_release_tx_skbs.isra.0 drivers/net/wireless/realtek/rtw89/pci.c:651
rtw89_pci_release_tx drivers/net/wireless/realtek/rtw89/pci.c:676
rtw89_pci_napi_poll drivers/net/wireless/realtek/rtw89/pci.c:4238
__napi_poll net/core/dev.c:7495
net_rx_action net/core/dev.c:7557 net/core/dev.c:7684
handle_softirqs kernel/softirq.c:580
do_softirq.part.0 kernel/softirq.c:480
__local_bh_enable_ip kernel/softirq.c:407
rtw89_pci_interrupt_threadfn drivers/net/wireless/realtek/rtw89/pci.c:927
irq_thread_fn kernel/irq/manage.c:1133
irq_thread kernel/irq/manage.c:1257
kthread kernel/kthread.c:463
ret_from_fork arch/x86/kernel/process.c:154
ret_from_fork_asm arch/x86/entry/entry_64.S:258
It is a consequence of a race between the waiting and the signaling side
of the completion:
Waiting thread Completing thread
rtw89_core_tx_kick_off_and_wait()
rcu_assign_pointer(skb_data->wait, wait)
/* start waiting */
wait_for_completion_timeout()
rtw89_pci_tx_status()
rtw89_core_tx_wait_complete()
rcu_read_lock()
/* signals completion and
* proceeds further
*/
complete(&wait->completion)
rcu_read_unlock()
...
/* frees skb_data */
ieee80211_tx_status_ni()
/* returns (exit status doesn't matter) */
wait_for_completion_timeout()
...
/* accesses the already freed skb_data */
rcu_assign_pointer(skb_data->wait, NULL)
The completing side might proceed and free the underlying skb even before
the waiting side is fully awoken and run to execution. Actually the race
happens regardless of wait_for_completion_timeout() exit status, e.g.
the waiting side may hit a timeout and the concurrent completing side is
still able to free the skb.
Skbs which are sent by rtw89_core_tx_kick_off_and_wait() are owned by the
driver. They don't come from core ieee80211 stack so no need to pass them
to ieee80211_tx_status_ni() on completing side.
Introduce a work function which will act as a garbage collector for
rtw89_tx_wait_info objects and the associated skbs. Thus no potentially
heavy locks are required on the completing side.
Found by Linux Verification Center (linuxtesting.org).
Fixes: 1ae5ca615285 ("wifi: rtw89: add function to wait for completion of TX skbs")
Cc: stable@vger.kernel.org
Suggested-by: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
---
v3: - decrease waiting timeout in rtw89_tx_wait_work() (Zong-Zhe)
- clear tx_waits list from rtw89_hci_reset(), too (Zong-Zhe)
- keep RCU updating for skb_data->wait (Zong-Zhe)
- keep the old order of calls in rtw89_pci_tx_status() (Zong-Zhe)
- drop wait->finished as complete_all() would make the completion be
done permanently (me)
v2: - use a work function to manage release of tx_waits and associated skbs (Zong-Zhe)
FWIW, I think RCU locking becomes unnecessary after the next patch
[PATCH rtw v3 2/5] wifi: rtw89: fix tx_wait initialization race
but let's keep it if you feel that's more safe.
drivers/net/wireless/realtek/rtw89/core.c | 28 ++++++++++++++---
drivers/net/wireless/realtek/rtw89/core.h | 38 +++++++++++++++++++++--
drivers/net/wireless/realtek/rtw89/pci.c | 3 +-
drivers/net/wireless/realtek/rtw89/ser.c | 2 ++
4 files changed, 63 insertions(+), 8 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtw89/core.c b/drivers/net/wireless/realtek/rtw89/core.c
index 57590f5577a3..5c964283cd67 100644
--- a/drivers/net/wireless/realtek/rtw89/core.c
+++ b/drivers/net/wireless/realtek/rtw89/core.c
@@ -1073,6 +1073,14 @@ rtw89_core_tx_update_desc_info(struct rtw89_dev *rtwdev,
}
}
+static void rtw89_tx_wait_work(struct wiphy *wiphy, struct wiphy_work *work)
+{
+ struct rtw89_dev *rtwdev = container_of(work, struct rtw89_dev,
+ tx_wait_work);
+
+ rtw89_tx_wait_list_clear(rtwdev);
+}
+
void rtw89_core_tx_kick_off(struct rtw89_dev *rtwdev, u8 qsel)
{
u8 ch_dma;
@@ -1090,6 +1098,8 @@ int rtw89_core_tx_kick_off_and_wait(struct rtw89_dev *rtwdev, struct sk_buff *sk
unsigned long time_left;
int ret = 0;
+ lockdep_assert_wiphy(rtwdev->hw->wiphy);
+
wait = kzalloc(sizeof(*wait), GFP_KERNEL);
if (!wait) {
rtw89_core_tx_kick_off(rtwdev, qsel);
@@ -1098,17 +1108,22 @@ int rtw89_core_tx_kick_off_and_wait(struct rtw89_dev *rtwdev, struct sk_buff *sk
init_completion(&wait->completion);
rcu_assign_pointer(skb_data->wait, wait);
+ wait->skb = skb;
rtw89_core_tx_kick_off(rtwdev, qsel);
time_left = wait_for_completion_timeout(&wait->completion,
msecs_to_jiffies(timeout));
- if (time_left == 0)
+
+ if (time_left == 0) {
ret = -ETIMEDOUT;
- else if (!wait->tx_done)
- ret = -EAGAIN;
+ list_add_tail(&wait->list, &rtwdev->tx_waits);
+ wiphy_work_queue(rtwdev->hw->wiphy, &rtwdev->tx_wait_work);
- rcu_assign_pointer(skb_data->wait, NULL);
- kfree_rcu(wait, rcu_head);
+ } else {
+ if (!wait->tx_done)
+ ret = -EAGAIN;
+ rtw89_tx_wait_release(&wait->rcu_head);
+ }
return ret;
}
@@ -4972,6 +4987,7 @@ void rtw89_core_stop(struct rtw89_dev *rtwdev)
clear_bit(RTW89_FLAG_RUNNING, rtwdev->flags);
wiphy_work_cancel(wiphy, &rtwdev->c2h_work);
+ wiphy_work_cancel(wiphy, &rtwdev->tx_wait_work);
wiphy_work_cancel(wiphy, &rtwdev->cancel_6ghz_probe_work);
wiphy_work_cancel(wiphy, &btc->eapol_notify_work);
wiphy_work_cancel(wiphy, &btc->arp_notify_work);
@@ -5203,6 +5219,7 @@ int rtw89_core_init(struct rtw89_dev *rtwdev)
INIT_LIST_HEAD(&rtwdev->scan_info.pkt_list[band]);
}
INIT_LIST_HEAD(&rtwdev->scan_info.chan_list);
+ INIT_LIST_HEAD(&rtwdev->tx_waits);
INIT_WORK(&rtwdev->ba_work, rtw89_core_ba_work);
INIT_WORK(&rtwdev->txq_work, rtw89_core_txq_work);
INIT_DELAYED_WORK(&rtwdev->txq_reinvoke_work, rtw89_core_txq_reinvoke_work);
@@ -5233,6 +5250,7 @@ int rtw89_core_init(struct rtw89_dev *rtwdev)
wiphy_work_init(&rtwdev->c2h_work, rtw89_fw_c2h_work);
wiphy_work_init(&rtwdev->ips_work, rtw89_ips_work);
wiphy_work_init(&rtwdev->cancel_6ghz_probe_work, rtw89_cancel_6ghz_probe_work);
+ wiphy_work_init(&rtwdev->tx_wait_work, rtw89_tx_wait_work);
INIT_WORK(&rtwdev->load_firmware_work, rtw89_load_firmware_work);
skb_queue_head_init(&rtwdev->c2h_queue);
diff --git a/drivers/net/wireless/realtek/rtw89/core.h b/drivers/net/wireless/realtek/rtw89/core.h
index 43e10278e14d..9b22bb116af9 100644
--- a/drivers/net/wireless/realtek/rtw89/core.h
+++ b/drivers/net/wireless/realtek/rtw89/core.h
@@ -3506,9 +3506,12 @@ struct rtw89_phy_rate_pattern {
bool enable;
};
+#define RTW89_TX_WAIT_DEFAULT_TIMEOUT 10
struct rtw89_tx_wait_info {
struct rcu_head rcu_head;
+ struct list_head list;
struct completion completion;
+ struct sk_buff *skb;
bool tx_done;
};
@@ -5925,6 +5928,9 @@ struct rtw89_dev {
/* used to protect rpwm */
spinlock_t rpwm_lock;
+ struct list_head tx_waits;
+ struct wiphy_work tx_wait_work;
+
struct rtw89_cam_info cam_info;
struct sk_buff_head c2h_queue;
@@ -6181,6 +6187,30 @@ rtw89_assoc_link_rcu_dereference(struct rtw89_dev *rtwdev, u8 macid)
list_first_entry_or_null(&p->dlink_pool, typeof(*p->links_inst), dlink_schd); \
})
+static inline void rtw89_tx_wait_release(struct rcu_head *rcu_head)
+{
+ struct rtw89_tx_wait_info *wait =
+ container_of(rcu_head, struct rtw89_tx_wait_info, rcu_head);
+
+ dev_kfree_skb_any(wait->skb);
+ kfree(wait);
+}
+
+static inline void rtw89_tx_wait_list_clear(struct rtw89_dev *rtwdev)
+{
+ struct rtw89_tx_wait_info *wait, *tmp;
+
+ lockdep_assert_wiphy(rtwdev->hw->wiphy);
+
+ list_for_each_entry_safe(wait, tmp, &rtwdev->tx_waits, list) {
+ if (!wait_for_completion_timeout(&wait->completion,
+ RTW89_TX_WAIT_DEFAULT_TIMEOUT))
+ continue;
+ list_del(&wait->list);
+ call_rcu(&wait->rcu_head, rtw89_tx_wait_release);
+ }
+}
+
static inline int rtw89_hci_tx_write(struct rtw89_dev *rtwdev,
struct rtw89_core_tx_request *tx_req)
{
@@ -6190,6 +6220,7 @@ static inline int rtw89_hci_tx_write(struct rtw89_dev *rtwdev,
static inline void rtw89_hci_reset(struct rtw89_dev *rtwdev)
{
rtwdev->hci.ops->reset(rtwdev);
+ rtw89_tx_wait_list_clear(rtwdev);
}
static inline int rtw89_hci_start(struct rtw89_dev *rtwdev)
@@ -7258,11 +7289,12 @@ static inline struct sk_buff *rtw89_alloc_skb_for_rx(struct rtw89_dev *rtwdev,
return dev_alloc_skb(length);
}
-static inline void rtw89_core_tx_wait_complete(struct rtw89_dev *rtwdev,
+static inline bool rtw89_core_tx_wait_complete(struct rtw89_dev *rtwdev,
struct rtw89_tx_skb_data *skb_data,
bool tx_done)
{
struct rtw89_tx_wait_info *wait;
+ bool ret = false;
rcu_read_lock();
@@ -7270,11 +7302,13 @@ static inline void rtw89_core_tx_wait_complete(struct rtw89_dev *rtwdev,
if (!wait)
goto out;
+ ret = true;
wait->tx_done = tx_done;
- complete(&wait->completion);
+ complete_all(&wait->completion);
out:
rcu_read_unlock();
+ return ret;
}
static inline bool rtw89_is_mlo_1_1(struct rtw89_dev *rtwdev)
diff --git a/drivers/net/wireless/realtek/rtw89/pci.c b/drivers/net/wireless/realtek/rtw89/pci.c
index a669f2f843aa..4e3034b44f56 100644
--- a/drivers/net/wireless/realtek/rtw89/pci.c
+++ b/drivers/net/wireless/realtek/rtw89/pci.c
@@ -464,7 +464,8 @@ static void rtw89_pci_tx_status(struct rtw89_dev *rtwdev,
struct rtw89_tx_skb_data *skb_data = RTW89_TX_SKB_CB(skb);
struct ieee80211_tx_info *info;
- rtw89_core_tx_wait_complete(rtwdev, skb_data, tx_status == RTW89_TX_DONE);
+ if (rtw89_core_tx_wait_complete(rtwdev, skb_data, tx_status == RTW89_TX_DONE))
+ return;
info = IEEE80211_SKB_CB(skb);
ieee80211_tx_info_clear_status(info);
diff --git a/drivers/net/wireless/realtek/rtw89/ser.c b/drivers/net/wireless/realtek/rtw89/ser.c
index bb39fdbcba0d..fe7beff8c424 100644
--- a/drivers/net/wireless/realtek/rtw89/ser.c
+++ b/drivers/net/wireless/realtek/rtw89/ser.c
@@ -502,7 +502,9 @@ static void ser_reset_trx_st_hdl(struct rtw89_ser *ser, u8 evt)
}
drv_stop_rx(ser);
+ wiphy_lock(wiphy);
drv_trx_reset(ser);
+ wiphy_unlock(wiphy);
/* wait m3 */
hal_send_m2_event(ser);
--
2.51.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH rtw v3 2/5] wifi: rtw89: fix tx_wait initialization race
[not found] <20250828211245.178843-1-pchelkin@ispras.ru>
2025-08-28 21:11 ` [PATCH rtw v3 1/5] wifi: rtw89: fix use-after-free in rtw89_core_tx_kick_off_and_wait() Fedor Pchelkin
@ 2025-08-28 21:11 ` Fedor Pchelkin
2025-08-29 9:40 ` Zong-Zhe Yang
1 sibling, 1 reply; 4+ messages in thread
From: Fedor Pchelkin @ 2025-08-28 21:11 UTC (permalink / raw)
To: Ping-Ke Shih, Zong-Zhe Yang, Bitterblue Smith
Cc: Fedor Pchelkin, Po-Hao Huang, linux-wireless, linux-kernel,
lvc-project, stable
Now that nullfunc skbs are recycled in a separate work item in the driver,
the following race during initialization and processing of those skbs
might lead to noticeable bugs:
Waiting thread Completing thread
rtw89_core_send_nullfunc()
rtw89_core_tx_write_link()
...
rtw89_pci_txwd_submit()
skb_data->wait = NULL
/* add skb to the queue */
skb_queue_tail(&txwd->queue, skb)
rtw89_pci_napi_poll()
...
rtw89_pci_release_txwd_skb()
/* get skb from the queue */
skb_unlink(skb, &txwd->queue)
rtw89_pci_tx_status()
rtw89_core_tx_wait_complete()
/* use incorrect skb_data->wait */
rtw89_core_tx_kick_off_and_wait()
/* assign skb_data->wait but too late */
The value of skb_data->wait indicates whether skb is passed on to the
core ieee80211 stack or released by the driver itself. So assure that by
the time skb is added to txwd queue and becomes visible to the completing
side, it has already allocated tx_wait-related data (in case it's needed).
Found by Linux Verification Center (linuxtesting.org).
Fixes: 1ae5ca615285 ("wifi: rtw89: add function to wait for completion of TX skbs")
Cc: stable@vger.kernel.org
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
---
drivers/net/wireless/realtek/rtw89/core.c | 30 ++++++++++++++---------
drivers/net/wireless/realtek/rtw89/pci.c | 2 --
2 files changed, 18 insertions(+), 14 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtw89/core.c b/drivers/net/wireless/realtek/rtw89/core.c
index 5c964283cd67..57f20559dfde 100644
--- a/drivers/net/wireless/realtek/rtw89/core.c
+++ b/drivers/net/wireless/realtek/rtw89/core.c
@@ -1094,20 +1094,12 @@ int rtw89_core_tx_kick_off_and_wait(struct rtw89_dev *rtwdev, struct sk_buff *sk
int qsel, unsigned int timeout)
{
struct rtw89_tx_skb_data *skb_data = RTW89_TX_SKB_CB(skb);
- struct rtw89_tx_wait_info *wait;
+ struct rtw89_tx_wait_info *wait = skb_data->wait;
unsigned long time_left;
int ret = 0;
lockdep_assert_wiphy(rtwdev->hw->wiphy);
- wait = kzalloc(sizeof(*wait), GFP_KERNEL);
- if (!wait) {
- rtw89_core_tx_kick_off(rtwdev, qsel);
- return 0;
- }
-
- init_completion(&wait->completion);
- rcu_assign_pointer(skb_data->wait, wait);
wait->skb = skb;
rtw89_core_tx_kick_off(rtwdev, qsel);
@@ -1172,10 +1164,12 @@ int rtw89_h2c_tx(struct rtw89_dev *rtwdev,
static int rtw89_core_tx_write_link(struct rtw89_dev *rtwdev,
struct rtw89_vif_link *rtwvif_link,
struct rtw89_sta_link *rtwsta_link,
- struct sk_buff *skb, int *qsel, bool sw_mld)
+ struct sk_buff *skb, int *qsel, bool sw_mld,
+ struct rtw89_tx_wait_info *wait)
{
struct ieee80211_sta *sta = rtwsta_link_to_sta_safe(rtwsta_link);
struct ieee80211_vif *vif = rtwvif_link_to_vif(rtwvif_link);
+ struct rtw89_tx_skb_data *skb_data = RTW89_TX_SKB_CB(skb);
struct rtw89_vif *rtwvif = rtwvif_link->rtwvif;
struct rtw89_core_tx_request tx_req = {};
int ret;
@@ -1192,6 +1186,8 @@ static int rtw89_core_tx_write_link(struct rtw89_dev *rtwdev,
rtw89_core_tx_update_desc_info(rtwdev, &tx_req);
rtw89_core_tx_wake(rtwdev, &tx_req);
+ rcu_assign_pointer(skb_data->wait, wait);
+
ret = rtw89_hci_tx_write(rtwdev, &tx_req);
if (ret) {
rtw89_err(rtwdev, "failed to transmit skb to HCI\n");
@@ -1228,7 +1224,8 @@ int rtw89_core_tx_write(struct rtw89_dev *rtwdev, struct ieee80211_vif *vif,
}
}
- return rtw89_core_tx_write_link(rtwdev, rtwvif_link, rtwsta_link, skb, qsel, false);
+ return rtw89_core_tx_write_link(rtwdev, rtwvif_link, rtwsta_link, skb, qsel, false,
+ NULL);
}
static __le32 rtw89_build_txwd_body0(struct rtw89_tx_desc_info *desc_info)
@@ -3426,6 +3423,7 @@ int rtw89_core_send_nullfunc(struct rtw89_dev *rtwdev, struct rtw89_vif_link *rt
struct ieee80211_vif *vif = rtwvif_link_to_vif(rtwvif_link);
int link_id = ieee80211_vif_is_mld(vif) ? rtwvif_link->link_id : -1;
struct rtw89_sta_link *rtwsta_link;
+ struct rtw89_tx_wait_info *wait;
struct ieee80211_sta *sta;
struct ieee80211_hdr *hdr;
struct rtw89_sta *rtwsta;
@@ -3435,6 +3433,12 @@ int rtw89_core_send_nullfunc(struct rtw89_dev *rtwdev, struct rtw89_vif_link *rt
if (vif->type != NL80211_IFTYPE_STATION || !vif->cfg.assoc)
return 0;
+ wait = kzalloc(sizeof(*wait), GFP_KERNEL);
+ if (!wait)
+ return -ENOMEM;
+
+ init_completion(&wait->completion);
+
rcu_read_lock();
sta = ieee80211_find_sta(vif, vif->cfg.ap_addr);
if (!sta) {
@@ -3459,7 +3463,8 @@ int rtw89_core_send_nullfunc(struct rtw89_dev *rtwdev, struct rtw89_vif_link *rt
goto out;
}
- ret = rtw89_core_tx_write_link(rtwdev, rtwvif_link, rtwsta_link, skb, &qsel, true);
+ ret = rtw89_core_tx_write_link(rtwdev, rtwvif_link, rtwsta_link, skb, &qsel, true,
+ wait);
if (ret) {
rtw89_warn(rtwdev, "nullfunc transmit failed: %d\n", ret);
dev_kfree_skb_any(skb);
@@ -3472,6 +3477,7 @@ int rtw89_core_send_nullfunc(struct rtw89_dev *rtwdev, struct rtw89_vif_link *rt
timeout);
out:
rcu_read_unlock();
+ kfree(wait);
return ret;
}
diff --git a/drivers/net/wireless/realtek/rtw89/pci.c b/drivers/net/wireless/realtek/rtw89/pci.c
index 4e3034b44f56..cb9682f306a6 100644
--- a/drivers/net/wireless/realtek/rtw89/pci.c
+++ b/drivers/net/wireless/realtek/rtw89/pci.c
@@ -1372,7 +1372,6 @@ static int rtw89_pci_txwd_submit(struct rtw89_dev *rtwdev,
struct pci_dev *pdev = rtwpci->pdev;
struct sk_buff *skb = tx_req->skb;
struct rtw89_pci_tx_data *tx_data = RTW89_PCI_TX_SKB_CB(skb);
- struct rtw89_tx_skb_data *skb_data = RTW89_TX_SKB_CB(skb);
bool en_wd_info = desc_info->en_wd_info;
u32 txwd_len;
u32 txwp_len;
@@ -1388,7 +1387,6 @@ static int rtw89_pci_txwd_submit(struct rtw89_dev *rtwdev,
}
tx_data->dma = dma;
- rcu_assign_pointer(skb_data->wait, NULL);
txwp_len = sizeof(*txwp_info);
txwd_len = chip->txwd_body_size;
--
2.51.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* RE: [PATCH rtw v3 1/5] wifi: rtw89: fix use-after-free in rtw89_core_tx_kick_off_and_wait()
2025-08-28 21:11 ` [PATCH rtw v3 1/5] wifi: rtw89: fix use-after-free in rtw89_core_tx_kick_off_and_wait() Fedor Pchelkin
@ 2025-08-29 7:42 ` Zong-Zhe Yang
0 siblings, 0 replies; 4+ messages in thread
From: Zong-Zhe Yang @ 2025-08-29 7:42 UTC (permalink / raw)
To: pchelkin@ispras.ru, Ping-Ke Shih, Bitterblue Smith
Cc: Bernie Huang, linux-wireless@vger.kernel.org,
linux-kernel@vger.kernel.org, lvc-project@linuxtesting.org,
stable@vger.kernel.org
Fedor Pchelkin <pchelkin@ispras.ru> wrote:
> There is a bug observed when rtw89_core_tx_kick_off_and_wait() tries to access already
> freed skb_data:
>
> BUG: KFENCE: use-after-free write in rtw89_core_tx_kick_off_and_wait
> drivers/net/wireless/realtek/rtw89/core.c:1110
>
> CPU: 6 UID: 0 PID: 41377 Comm: kworker/u64:24 Not tainted 6.17.0-rc1+ #1 PREEMPT(lazy)
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS edk2-20250523-14.fc42
> 05/23/2025
> Workqueue: events_unbound cfg80211_wiphy_work [cfg80211]
>
> Use-after-free write at 0x0000000020309d9d (in kfence-#251):
> rtw89_core_tx_kick_off_and_wait drivers/net/wireless/realtek/rtw89/core.c:1110
> rtw89_core_scan_complete drivers/net/wireless/realtek/rtw89/core.c:5338
> rtw89_hw_scan_complete_cb drivers/net/wireless/realtek/rtw89/fw.c:7979
> rtw89_chanctx_proceed_cb drivers/net/wireless/realtek/rtw89/chan.c:3165
> rtw89_chanctx_proceed drivers/net/wireless/realtek/rtw89/chan.h:141
> rtw89_hw_scan_complete drivers/net/wireless/realtek/rtw89/fw.c:8012
> rtw89_mac_c2h_scanofld_rsp drivers/net/wireless/realtek/rtw89/mac.c:5059
> rtw89_fw_c2h_work drivers/net/wireless/realtek/rtw89/fw.c:6758
> process_one_work kernel/workqueue.c:3241 worker_thread kernel/workqueue.c:3400
> kthread kernel/kthread.c:463 ret_from_fork arch/x86/kernel/process.c:154
> ret_from_fork_asm arch/x86/entry/entry_64.S:258
>
> kfence-#251: 0x0000000056e2393d-0x000000009943cb62, size=232,
> cache=skbuff_head_cache
>
> allocated by task 41377 on cpu 6 at 77869.159548s (0.009551s ago):
> __alloc_skb net/core/skbuff.c:659
> __netdev_alloc_skb net/core/skbuff.c:734 ieee80211_nullfunc_get
> net/mac80211/tx.c:5844 rtw89_core_send_nullfunc
> drivers/net/wireless/realtek/rtw89/core.c:3431
> rtw89_core_scan_complete drivers/net/wireless/realtek/rtw89/core.c:5338
> rtw89_hw_scan_complete_cb drivers/net/wireless/realtek/rtw89/fw.c:7979
> rtw89_chanctx_proceed_cb drivers/net/wireless/realtek/rtw89/chan.c:3165
> rtw89_chanctx_proceed drivers/net/wireless/realtek/rtw89/chan.c:3194
> rtw89_hw_scan_complete drivers/net/wireless/realtek/rtw89/fw.c:8012
> rtw89_mac_c2h_scanofld_rsp drivers/net/wireless/realtek/rtw89/mac.c:5059
> rtw89_fw_c2h_work drivers/net/wireless/realtek/rtw89/fw.c:6758
> process_one_work kernel/workqueue.c:3241 worker_thread kernel/workqueue.c:3400
> kthread kernel/kthread.c:463 ret_from_fork arch/x86/kernel/process.c:154
> ret_from_fork_asm arch/x86/entry/entry_64.S:258
>
> freed by task 1045 on cpu 9 at 77869.168393s (0.001557s ago):
> ieee80211_tx_status_skb net/mac80211/status.c:1117 rtw89_pci_release_txwd_skb
> drivers/net/wireless/realtek/rtw89/pci.c:564
> rtw89_pci_release_tx_skbs.isra.0 drivers/net/wireless/realtek/rtw89/pci.c:651
> rtw89_pci_release_tx drivers/net/wireless/realtek/rtw89/pci.c:676
> rtw89_pci_napi_poll drivers/net/wireless/realtek/rtw89/pci.c:4238
> __napi_poll net/core/dev.c:7495
> net_rx_action net/core/dev.c:7557 net/core/dev.c:7684 handle_softirqs
> kernel/softirq.c:580
> do_softirq.part.0 kernel/softirq.c:480
> __local_bh_enable_ip kernel/softirq.c:407 rtw89_pci_interrupt_threadfn
> drivers/net/wireless/realtek/rtw89/pci.c:927
> irq_thread_fn kernel/irq/manage.c:1133
> irq_thread kernel/irq/manage.c:1257
> kthread kernel/kthread.c:463
> ret_from_fork arch/x86/kernel/process.c:154 ret_from_fork_asm
> arch/x86/entry/entry_64.S:258
>
> It is a consequence of a race between the waiting and the signaling side of the completion:
>
> Waiting thread Completing thread
>
> rtw89_core_tx_kick_off_and_wait()
> rcu_assign_pointer(skb_data->wait, wait)
> /* start waiting */
> wait_for_completion_timeout()
> rtw89_pci_tx_status()
> rtw89_core_tx_wait_complete()
> rcu_read_lock()
> /* signals completion and
> * proceeds further
> */
>
> complete(&wait->completion)
> rcu_read_unlock()
> ...
> /* frees skb_data */
> ieee80211_tx_status_ni()
> /* returns (exit status doesn't matter) */
> wait_for_completion_timeout()
> ...
> /* accesses the already freed skb_data */
> rcu_assign_pointer(skb_data->wait, NULL)
>
> The completing side might proceed and free the underlying skb even before the waiting side
> is fully awoken and run to execution. Actually the race happens regardless of
> wait_for_completion_timeout() exit status, e.g.
> the waiting side may hit a timeout and the concurrent completing side is still able to free the
> skb.
>
> Skbs which are sent by rtw89_core_tx_kick_off_and_wait() are owned by the driver. They
> don't come from core ieee80211 stack so no need to pass them to ieee80211_tx_status_ni()
> on completing side.
>
> Introduce a work function which will act as a garbage collector for rtw89_tx_wait_info objects
> and the associated skbs. Thus no potentially heavy locks are required on the completing
> side.
>
> Found by Linux Verification Center (linuxtesting.org).
>
> Fixes: 1ae5ca615285 ("wifi: rtw89: add function to wait for completion of TX skbs")
> Cc: stable@vger.kernel.org
> Suggested-by: Zong-Zhe Yang <kevin_yang@realtek.com>
> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
> ---
>
> v3: - decrease waiting timeout in rtw89_tx_wait_work() (Zong-Zhe)
> - clear tx_waits list from rtw89_hci_reset(), too (Zong-Zhe)
> - keep RCU updating for skb_data->wait (Zong-Zhe)
> - keep the old order of calls in rtw89_pci_tx_status() (Zong-Zhe)
> - drop wait->finished as complete_all() would make the completion be
> done permanently (me)
>
> v2: - use a work function to manage release of tx_waits and associated skbs (Zong-Zhe)
>
>
> FWIW, I think RCU locking becomes unnecessary after the next patch [PATCH rtw v3 2/5] wifi:
> rtw89: fix tx_wait initialization race but let's keep it if you feel that's more safe.
>
Thanks. My thoughts are simple.
1. If it doesn't lead to bugs (i.e. not really necessary changes), keep it.
2. Keeping RCU gives us some room, if someday somehow we need to extend flow.
Otherwise, we need to add it back again at that time.
3. Keep free side safe (kfree_rcu(@wait)) and doesn't depend on how complete() or
wait_for_completion*() are implemented. (where completion is in @wait)
(If I change my mind after reading [PATCH v3 2/5], I will send my new comments.)
>
> drivers/net/wireless/realtek/rtw89/core.c | 28 ++++++++++++++---
> drivers/net/wireless/realtek/rtw89/core.h | 38 +++++++++++++++++++++--
> drivers/net/wireless/realtek/rtw89/pci.c | 3 +- drivers/net/wireless/realtek/rtw89/ser.c
> | 2 ++
> 4 files changed, 63 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/wireless/realtek/rtw89/core.c
> b/drivers/net/wireless/realtek/rtw89/core.c
> index 57590f5577a3..5c964283cd67 100644
> --- a/drivers/net/wireless/realtek/rtw89/core.c
> +++ b/drivers/net/wireless/realtek/rtw89/core.c
> @@ -1073,6 +1073,14 @@ rtw89_core_tx_update_desc_info(struct rtw89_dev *rtwdev,
> }
> }
>
> +static void rtw89_tx_wait_work(struct wiphy *wiphy, struct wiphy_work
> +*work) {
> + struct rtw89_dev *rtwdev = container_of(work, struct rtw89_dev,
> + tx_wait_work);
> +
> + rtw89_tx_wait_list_clear(rtwdev);
> +}
> +
> void rtw89_core_tx_kick_off(struct rtw89_dev *rtwdev, u8 qsel) {
> u8 ch_dma;
> @@ -1090,6 +1098,8 @@ int rtw89_core_tx_kick_off_and_wait(struct rtw89_dev *rtwdev,
> struct sk_buff *sk
> unsigned long time_left;
> int ret = 0;
>
> + lockdep_assert_wiphy(rtwdev->hw->wiphy);
> +
> wait = kzalloc(sizeof(*wait), GFP_KERNEL);
> if (!wait) {
> rtw89_core_tx_kick_off(rtwdev, qsel); @@ -1098,17 +1108,22 @@ int
> rtw89_core_tx_kick_off_and_wait(struct rtw89_dev *rtwdev, struct sk_buff *sk
>
> init_completion(&wait->completion);
> rcu_assign_pointer(skb_data->wait, wait);
> + wait->skb = skb;
>
Generally, fill wait's fields before publishing it.
(i.e. before rcu_assign_pointer(...))
> rtw89_core_tx_kick_off(rtwdev, qsel);
> time_left = wait_for_completion_timeout(&wait->completion,
> msecs_to_jiffies(timeout));
> - if (time_left == 0)
> +
> + if (time_left == 0) {
> ret = -ETIMEDOUT;
> - else if (!wait->tx_done)
> - ret = -EAGAIN;
> + list_add_tail(&wait->list, &rtwdev->tx_waits);
> + wiphy_work_queue(rtwdev->hw->wiphy, &rtwdev->tx_wait_work);
>
> - rcu_assign_pointer(skb_data->wait, NULL);
> - kfree_rcu(wait, rcu_head);
> + } else {
> + if (!wait->tx_done)
> + ret = -EAGAIN;
> + rtw89_tx_wait_release(&wait->rcu_head);
> + }
>
> return ret;
> }
> @@ -4972,6 +4987,7 @@ void rtw89_core_stop(struct rtw89_dev *rtwdev)
> clear_bit(RTW89_FLAG_RUNNING, rtwdev->flags);
>
> wiphy_work_cancel(wiphy, &rtwdev->c2h_work);
> + wiphy_work_cancel(wiphy, &rtwdev->tx_wait_work);
> wiphy_work_cancel(wiphy, &rtwdev->cancel_6ghz_probe_work);
> wiphy_work_cancel(wiphy, &btc->eapol_notify_work);
> wiphy_work_cancel(wiphy, &btc->arp_notify_work); @@ -5203,6 +5219,7 @@ int
> rtw89_core_init(struct rtw89_dev *rtwdev)
> INIT_LIST_HEAD(&rtwdev->scan_info.pkt_list[band]);
> }
> INIT_LIST_HEAD(&rtwdev->scan_info.chan_list);
> + INIT_LIST_HEAD(&rtwdev->tx_waits);
> INIT_WORK(&rtwdev->ba_work, rtw89_core_ba_work);
> INIT_WORK(&rtwdev->txq_work, rtw89_core_txq_work);
> INIT_DELAYED_WORK(&rtwdev->txq_reinvoke_work, rtw89_core_txq_reinvoke_work);
> @@ -5233,6 +5250,7 @@ int rtw89_core_init(struct rtw89_dev *rtwdev)
> wiphy_work_init(&rtwdev->c2h_work, rtw89_fw_c2h_work);
> wiphy_work_init(&rtwdev->ips_work, rtw89_ips_work);
> wiphy_work_init(&rtwdev->cancel_6ghz_probe_work, rtw89_cancel_6ghz_probe_work);
> + wiphy_work_init(&rtwdev->tx_wait_work, rtw89_tx_wait_work);
> INIT_WORK(&rtwdev->load_firmware_work, rtw89_load_firmware_work);
>
> skb_queue_head_init(&rtwdev->c2h_queue);
> diff --git a/drivers/net/wireless/realtek/rtw89/core.h
> b/drivers/net/wireless/realtek/rtw89/core.h
> index 43e10278e14d..9b22bb116af9 100644
> --- a/drivers/net/wireless/realtek/rtw89/core.h
> +++ b/drivers/net/wireless/realtek/rtw89/core.h
> @@ -3506,9 +3506,12 @@ struct rtw89_phy_rate_pattern {
> bool enable;
> };
>
> +#define RTW89_TX_WAIT_DEFAULT_TIMEOUT 10
> struct rtw89_tx_wait_info {
> struct rcu_head rcu_head;
> + struct list_head list;
> struct completion completion;
> + struct sk_buff *skb;
> bool tx_done;
> };
>
> @@ -5925,6 +5928,9 @@ struct rtw89_dev {
> /* used to protect rpwm */
> spinlock_t rpwm_lock;
>
> + struct list_head tx_waits;
> + struct wiphy_work tx_wait_work;
> +
> struct rtw89_cam_info cam_info;
>
> struct sk_buff_head c2h_queue;
> @@ -6181,6 +6187,30 @@ rtw89_assoc_link_rcu_dereference(struct rtw89_dev *rtwdev, u8
> macid)
> list_first_entry_or_null(&p->dlink_pool, typeof(*p->links_inst), dlink_schd); \
> })
>
> +static inline void rtw89_tx_wait_release(struct rcu_head *rcu_head) {
> + struct rtw89_tx_wait_info *wait =
> + container_of(rcu_head, struct rtw89_tx_wait_info, rcu_head);
> +
> + dev_kfree_skb_any(wait->skb);
> + kfree(wait);
> +}
> +
> +static inline void rtw89_tx_wait_list_clear(struct rtw89_dev *rtwdev) {
> + struct rtw89_tx_wait_info *wait, *tmp;
> +
> + lockdep_assert_wiphy(rtwdev->hw->wiphy);
> +
> + list_for_each_entry_safe(wait, tmp, &rtwdev->tx_waits, list) {
> + if (!wait_for_completion_timeout(&wait->completion,
> + RTW89_TX_WAIT_DEFAULT_TIMEOUT))
> + continue;
> + list_del(&wait->list);
> + call_rcu(&wait->rcu_head, rtw89_tx_wait_release);
> + }
> +}
> +
I feel dev_kfree_skb_any + kfree_rcu is fine at least for now.
For call_rcu, there is one problem to me.
Can rtw89_tx_wait_release be invoked after rmmod ?
e.g. one tx is never completed yet unfortunately -> user rmmod driver
-> release pending skb -> rtw89_tx_wait_list_clear -> ...
So, how about the follow-up ?
rtw89_tx_wait_release(struct rtw89_tx_wait_info *wait):
dev_kfree_skb_any(wait->skb)
kfree_rcu(wait)
rtw89_tx_wait_list_clear(...):
...
for each wait in list:
...
list_del
rtw89_tx_wait_release(wait)
> static inline int rtw89_hci_tx_write(struct rtw89_dev *rtwdev,
> struct rtw89_core_tx_request *tx_req) { @@ -6190,6 +6220,7
> @@ static inline int rtw89_hci_tx_write(struct rtw89_dev *rtwdev, static inline void
> rtw89_hci_reset(struct rtw89_dev *rtwdev) {
> rtwdev->hci.ops->reset(rtwdev);
> + rtw89_tx_wait_list_clear(rtwdev);
> }
>
> static inline int rtw89_hci_start(struct rtw89_dev *rtwdev) @@ -7258,11 +7289,12 @@
> static inline struct sk_buff *rtw89_alloc_skb_for_rx(struct rtw89_dev *rtwdev,
> return dev_alloc_skb(length);
> }
>
> -static inline void rtw89_core_tx_wait_complete(struct rtw89_dev *rtwdev,
> +static inline bool rtw89_core_tx_wait_complete(struct rtw89_dev
> +*rtwdev,
> struct rtw89_tx_skb_data *skb_data,
> bool tx_done)
> {
> struct rtw89_tx_wait_info *wait;
> + bool ret = false;
>
> rcu_read_lock();
>
> @@ -7270,11 +7302,13 @@ static inline void rtw89_core_tx_wait_complete(struct
> rtw89_dev *rtwdev,
> if (!wait)
> goto out;
>
> + ret = true;
> wait->tx_done = tx_done;
> - complete(&wait->completion);
> + complete_all(&wait->completion);
>
Maybe add a comment to hint.
For example, /* Don't access skb anymore after completing */
> out:
> rcu_read_unlock();
> + return ret;
> }
>
> static inline bool rtw89_is_mlo_1_1(struct rtw89_dev *rtwdev) diff --git
> a/drivers/net/wireless/realtek/rtw89/pci.c b/drivers/net/wireless/realtek/rtw89/pci.c
> index a669f2f843aa..4e3034b44f56 100644
> --- a/drivers/net/wireless/realtek/rtw89/pci.c
> +++ b/drivers/net/wireless/realtek/rtw89/pci.c
> @@ -464,7 +464,8 @@ static void rtw89_pci_tx_status(struct rtw89_dev *rtwdev,
> struct rtw89_tx_skb_data *skb_data = RTW89_TX_SKB_CB(skb);
> struct ieee80211_tx_info *info;
>
> - rtw89_core_tx_wait_complete(rtwdev, skb_data, tx_status == RTW89_TX_DONE);
> + if (rtw89_core_tx_wait_complete(rtwdev, skb_data, tx_status == RTW89_TX_DONE))
> + return;
>
> info = IEEE80211_SKB_CB(skb);
> ieee80211_tx_info_clear_status(info);
> diff --git a/drivers/net/wireless/realtek/rtw89/ser.c b/drivers/net/wireless/realtek/rtw89/ser.c
> index bb39fdbcba0d..fe7beff8c424 100644
> --- a/drivers/net/wireless/realtek/rtw89/ser.c
> +++ b/drivers/net/wireless/realtek/rtw89/ser.c
> @@ -502,7 +502,9 @@ static void ser_reset_trx_st_hdl(struct rtw89_ser *ser, u8 evt)
> }
>
> drv_stop_rx(ser);
> + wiphy_lock(wiphy);
> drv_trx_reset(ser);
> + wiphy_unlock(wiphy);
>
> /* wait m3 */
> hal_send_m2_event(ser);
> --
> 2.51.0
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH rtw v3 2/5] wifi: rtw89: fix tx_wait initialization race
2025-08-28 21:11 ` [PATCH rtw v3 2/5] wifi: rtw89: fix tx_wait initialization race Fedor Pchelkin
@ 2025-08-29 9:40 ` Zong-Zhe Yang
0 siblings, 0 replies; 4+ messages in thread
From: Zong-Zhe Yang @ 2025-08-29 9:40 UTC (permalink / raw)
To: Fedor Pchelkin, Ping-Ke Shih, Bitterblue Smith
Cc: Bernie Huang, linux-wireless@vger.kernel.org,
linux-kernel@vger.kernel.org, lvc-project@linuxtesting.org,
stable@vger.kernel.org
Fedor Pchelkin <pchelkin@ispras.ru> wrote:
> Now that nullfunc skbs are recycled in a separate work item in the driver, the following race
> during initialization and processing of those skbs might lead to noticeable bugs:
>
> Waiting thread Completing thread
>
> rtw89_core_send_nullfunc()
> rtw89_core_tx_write_link()
> ...
> rtw89_pci_txwd_submit()
> skb_data->wait = NULL
> /* add skb to the queue */
> skb_queue_tail(&txwd->queue, skb)
> rtw89_pci_napi_poll()
> ...
> rtw89_pci_release_txwd_skb()
> /* get skb from the queue */
> skb_unlink(skb, &txwd->queue)
> rtw89_pci_tx_status()
> rtw89_core_tx_wait_complete()
> /* use incorrect skb_data->wait
> */
> rtw89_core_tx_kick_off_and_wait()
> /* assign skb_data->wait but too late */
>
> The value of skb_data->wait indicates whether skb is passed on to the core ieee80211 stack
> or released by the driver itself. So assure that by the time skb is added to txwd queue and
> becomes visible to the completing side, it has already allocated tx_wait-related data (in case
> it's needed).
>
> Found by Linux Verification Center (linuxtesting.org).
>
> Fixes: 1ae5ca615285 ("wifi: rtw89: add function to wait for completion of TX skbs")
> Cc: stable@vger.kernel.org
> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
> ---
> drivers/net/wireless/realtek/rtw89/core.c | 30 ++++++++++++++---------
> drivers/net/wireless/realtek/rtw89/pci.c | 2 --
> 2 files changed, 18 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/net/wireless/realtek/rtw89/core.c
> b/drivers/net/wireless/realtek/rtw89/core.c
> index 5c964283cd67..57f20559dfde 100644
> --- a/drivers/net/wireless/realtek/rtw89/core.c
> +++ b/drivers/net/wireless/realtek/rtw89/core.c
> @@ -1094,20 +1094,12 @@ int rtw89_core_tx_kick_off_and_wait(struct rtw89_dev *rtwdev,
> struct sk_buff *sk
> int qsel, unsigned int timeout) {
> struct rtw89_tx_skb_data *skb_data = RTW89_TX_SKB_CB(skb);
> - struct rtw89_tx_wait_info *wait;
> + struct rtw89_tx_wait_info *wait = skb_data->wait;
wiphy_dereference(rtwdev->hw->wiphy, skb_data->wait)
> unsigned long time_left;
> int ret = 0;
>
> lockdep_assert_wiphy(rtwdev->hw->wiphy);
>
> - wait = kzalloc(sizeof(*wait), GFP_KERNEL);
> - if (!wait) {
> - rtw89_core_tx_kick_off(rtwdev, qsel);
> - return 0;
> - }
> -
> - init_completion(&wait->completion);
> - rcu_assign_pointer(skb_data->wait, wait);
> wait->skb = skb;
Also, move "wait->skb = skb" to where wait is initialized.
>
> rtw89_core_tx_kick_off(rtwdev, qsel); @@ -1172,10 +1164,12 @@ int
> rtw89_h2c_tx(struct rtw89_dev *rtwdev, static int rtw89_core_tx_write_link(struct
> rtw89_dev *rtwdev,
> struct rtw89_vif_link *rtwvif_link,
> struct rtw89_sta_link *rtwsta_link,
> - struct sk_buff *skb, int *qsel, bool sw_mld)
> + struct sk_buff *skb, int *qsel, bool sw_mld,
> + struct rtw89_tx_wait_info *wait)
> {
> struct ieee80211_sta *sta = rtwsta_link_to_sta_safe(rtwsta_link);
> struct ieee80211_vif *vif = rtwvif_link_to_vif(rtwvif_link);
> + struct rtw89_tx_skb_data *skb_data = RTW89_TX_SKB_CB(skb);
> struct rtw89_vif *rtwvif = rtwvif_link->rtwvif;
> struct rtw89_core_tx_request tx_req = {};
> int ret;
> @@ -1192,6 +1186,8 @@ static int rtw89_core_tx_write_link(struct rtw89_dev *rtwdev,
> rtw89_core_tx_update_desc_info(rtwdev, &tx_req);
> rtw89_core_tx_wake(rtwdev, &tx_req);
>
> + rcu_assign_pointer(skb_data->wait, wait);
> +
> ret = rtw89_hci_tx_write(rtwdev, &tx_req);
> if (ret) {
> rtw89_err(rtwdev, "failed to transmit skb to HCI\n"); @@ -1228,7 +1224,8
> @@ int rtw89_core_tx_write(struct rtw89_dev *rtwdev, struct ieee80211_vif *vif,
> }
> }
>
> - return rtw89_core_tx_write_link(rtwdev, rtwvif_link, rtwsta_link, skb, qsel, false);
> + return rtw89_core_tx_write_link(rtwdev, rtwvif_link, rtwsta_link, skb, qsel, false,
> + NULL);
> }
>
> static __le32 rtw89_build_txwd_body0(struct rtw89_tx_desc_info *desc_info) @@ -3426,6
> +3423,7 @@ int rtw89_core_send_nullfunc(struct rtw89_dev *rtwdev, struct rtw89_vif_link
> *rt
> struct ieee80211_vif *vif = rtwvif_link_to_vif(rtwvif_link);
> int link_id = ieee80211_vif_is_mld(vif) ? rtwvif_link->link_id : -1;
> struct rtw89_sta_link *rtwsta_link;
> + struct rtw89_tx_wait_info *wait;
> struct ieee80211_sta *sta;
> struct ieee80211_hdr *hdr;
> struct rtw89_sta *rtwsta;
> @@ -3435,6 +3433,12 @@ int rtw89_core_send_nullfunc(struct rtw89_dev *rtwdev, struct
> rtw89_vif_link *rt
> if (vif->type != NL80211_IFTYPE_STATION || !vif->cfg.assoc)
> return 0;
>
> + wait = kzalloc(sizeof(*wait), GFP_KERNEL);
> + if (!wait)
> + return -ENOMEM;
> +
> + init_completion(&wait->completion);
> +
> rcu_read_lock();
> sta = ieee80211_find_sta(vif, vif->cfg.ap_addr);
> if (!sta) {
> @@ -3459,7 +3463,8 @@ int rtw89_core_send_nullfunc(struct rtw89_dev *rtwdev, struct
> rtw89_vif_link *rt
> goto out;
> }
>
Fill wait->skb as mentioned above.
> - ret = rtw89_core_tx_write_link(rtwdev, rtwvif_link, rtwsta_link, skb, &qsel, true);
> + ret = rtw89_core_tx_write_link(rtwdev, rtwvif_link, rtwsta_link, skb, &qsel, true,
> + wait);
> if (ret) {
> rtw89_warn(rtwdev, "nullfunc transmit failed: %d\n", ret);
> dev_kfree_skb_any(skb);
> @@ -3472,6 +3477,7 @@ int rtw89_core_send_nullfunc(struct rtw89_dev *rtwdev, struct
> rtw89_vif_link *rt
> timeout);
> out:
> rcu_read_unlock();
> + kfree(wait);
>
> return ret;
> }
> diff --git a/drivers/net/wireless/realtek/rtw89/pci.c b/drivers/net/wireless/realtek/rtw89/pci.c
> index 4e3034b44f56..cb9682f306a6 100644
> --- a/drivers/net/wireless/realtek/rtw89/pci.c
> +++ b/drivers/net/wireless/realtek/rtw89/pci.c
> @@ -1372,7 +1372,6 @@ static int rtw89_pci_txwd_submit(struct rtw89_dev *rtwdev,
> struct pci_dev *pdev = rtwpci->pdev;
> struct sk_buff *skb = tx_req->skb;
> struct rtw89_pci_tx_data *tx_data = RTW89_PCI_TX_SKB_CB(skb);
> - struct rtw89_tx_skb_data *skb_data = RTW89_TX_SKB_CB(skb);
> bool en_wd_info = desc_info->en_wd_info;
> u32 txwd_len;
> u32 txwp_len;
> @@ -1388,7 +1387,6 @@ static int rtw89_pci_txwd_submit(struct rtw89_dev *rtwdev,
> }
>
> tx_data->dma = dma;
> - rcu_assign_pointer(skb_data->wait, NULL);
>
> txwp_len = sizeof(*txwp_info);
> txwd_len = chip->txwd_body_size;
> --
> 2.51.0
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2025-08-29 9:41 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <20250828211245.178843-1-pchelkin@ispras.ru>
2025-08-28 21:11 ` [PATCH rtw v3 1/5] wifi: rtw89: fix use-after-free in rtw89_core_tx_kick_off_and_wait() Fedor Pchelkin
2025-08-29 7:42 ` Zong-Zhe Yang
2025-08-28 21:11 ` [PATCH rtw v3 2/5] wifi: rtw89: fix tx_wait initialization race Fedor Pchelkin
2025-08-29 9:40 ` Zong-Zhe Yang
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