[PATCH 5.10 021/147] PM: sleep: wakeirq: harden dev_pm_clear_wake_irq() against races

Sasha Levin
2026-02-28T18:17:52Z

From: Gui-Dong Han <hanguidong02@gmail.com>

[ Upstream commit 5c9ecd8e6437cd55a38ea4f1e1d19cee8e226cb8 ]

dev_pm_clear_wake_irq() currently uses a dangerous pattern where
dev->power.wakeirq is read and checked for NULL outside the lock.
If two callers invoke this function concurrently, both might see
a valid pointer and proceed. This could result in a double-free
when the second caller acquires the lock and tries to release the
same object.

Address this by removing the lockless check of dev->power.wakeirq.
Instead, acquire dev->power.lock immediately to ensure the check and
the subsequent operations are atomic. If dev->power.wakeirq is NULL
under the lock, simply unlock and return. This guarantees that
concurrent calls cannot race to free the same object.

Based on a quick scan of current users, I did not find an actual bug as
drivers seem to rely on their own synchronization. However, since
asynchronous usage patterns exist (e.g., in
drivers/net/wireless/ti/wlcore), I believe a race is theoretically
possible if the API is used less carefully in the future. This change
hardens the API to be robust against such cases.

Fixes: 4990d4fe327b ("PM / Wakeirq: Add automated device wake IRQ handling")
Signed-off-by: Gui-Dong Han <hanguidong02@gmail.com>
Link: https://patch.msgid.link/20260203031943.1924-1-hanguidong02@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/base/power/wakeirq.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c
index 4f4310724fee5..d22fc66a387d7 100644
--- a/drivers/base/power/wakeirq.c
+++ b/drivers/base/power/wakeirq.c
@@ -86,13 +86,16 @@ EXPORT_SYMBOL_GPL(dev_pm_set_wake_irq);
*/
void dev_pm_clear_wake_irq(struct device *dev)
{
- struct wake_irq *wirq = dev->power.wakeirq;
+ struct wake_irq *wirq;
unsigned long flags;

- if (!wirq)
+ spin_lock_irqsave(&dev->power.lock, flags);
+ wirq = dev->power.wakeirq;
+ if (!wirq) {
+ spin_unlock_irqrestore(&dev->power.lock, flags);
return;
+ }

- spin_lock_irqsave(&dev->power.lock, flags);
device_wakeup_detach_irq(dev);
dev->power.wakeirq = NULL;
spin_unlock_irqrestore(&dev->power.lock, flags);
--
2.51.0