Thread (518 messages) 518 messages, 9 authors, 1d ago

[PATCH 6.6 024/508] wifi: rtlwifi: pci: fix possible use-after-free caused by unfinished irq_prepare_bcn_tasklet

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2026-05-20 18:29:57
Also in: stable
Subsystem: realtek wireless driver (rtlwifi family), the rest · Maintainers: Ping-Ke Shih, Linus Torvalds

6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Duoming Zhou <redacted>

[ Upstream commit 039cd522dc70151da13329a5e3ae19b1736f468a ]

The irq_prepare_bcn_tasklet is initialized in rtl_pci_init() and
scheduled when RTL_IMR_BCNINT interrupt is triggered by hardware.
But it is never killed in rtl_pci_deinit(). When the rtlwifi card
probe fails or is being detached, the ieee80211_hw is deallocated.
However, irq_prepare_bcn_tasklet may still be running or pending,
leading to use-after-free when the freed ieee80211_hw is accessed
in _rtl_pci_prepare_bcn_tasklet().

Similar to irq_tasklet, add tasklet_kill() in rtl_pci_deinit() to
ensure that irq_prepare_bcn_tasklet is properly terminated before
the ieee80211_hw is released.

The issue was identified through static analysis.

Fixes: 0c8173385e54 ("rtl8192ce: Add new driver")
Signed-off-by: Duoming Zhou <redacted>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20260223045522.48377-1-duoming@zju.edu.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/realtek/rtlwifi/pci.c | 1 +
 1 file changed, 1 insertion(+)
diff --git a/drivers/net/wireless/realtek/rtlwifi/pci.c b/drivers/net/wireless/realtek/rtlwifi/pci.c
index 40112b2c37775..b978d31e47ca9 100644
--- a/drivers/net/wireless/realtek/rtlwifi/pci.c
+++ b/drivers/net/wireless/realtek/rtlwifi/pci.c
@@ -1675,6 +1675,7 @@ static void rtl_pci_deinit(struct ieee80211_hw *hw)
 
 	synchronize_irq(rtlpci->pdev->irq);
 	tasklet_kill(&rtlpriv->works.irq_tasklet);
+	tasklet_kill(&rtlpriv->works.irq_prepare_bcn_tasklet);
 	cancel_work_sync(&rtlpriv->works.lps_change_work);
 }
 
-- 
2.53.0


Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help