linux-kernel - [PATCH 1/3] power: supply: wm97xx: Fix NULL pointer dereference in power_supply

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <97b55f0479a932eea7213844bf66f28a974e27a2.1766270196.git.waqar.hameed@axis.com>
Date: Sat, 20 Dec 2025 23:46:24 +0100
From: Waqar Hameed <waqar.hameed@...s.com>
To: Sebastian Reichel <sre@...nel.org>, Anton Vorontsov
	<avorontsov@...mvista.com>, Marek Vasut <marek.vasut@...il.com>
CC: <kernel@...s.com>, <linux-pm@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
Subject: [PATCH 1/3] power: supply: wm97xx: Fix NULL pointer dereference in
 power_supply_changed()

In `probe()`, `request_irq()` is called before allocating/registering a
`power_supply` handle. If an interrupt is fired between the call to
`request_irq()` and `power_supply_register()`, the `power_supply` handle
will be used uninitialized in `power_supply_changed()` in
`wm97xx_bat_update()` (triggered from the interrupt handler). This will
lead to a `NULL` pointer dereference since

Fix this racy `NULL` pointer dereference by making sure the IRQ is
requested _after_ the registration of the `power_supply` handle. Since
the IRQ is the last thing requests in the `probe()` now, remove the
error path for freeing it. Instead add one for unregistering the
`power_supply` handle when IRQ request fails.

Fixes: 7c87942aef52 ("wm97xx_battery: Use irq to detect charger state")
Signed-off-by: Waqar Hameed <waqar.hameed@...s.com>
---
 drivers/power/supply/wm97xx_battery.c | 34 +++++++++++++++------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/drivers/power/supply/wm97xx_battery.c b/drivers/power/supply/wm97xx_battery.c
index b3b0c37a9dd2d..f00722c88c6fe 100644
--- a/drivers/power/supply/wm97xx_battery.c
+++ b/drivers/power/supply/wm97xx_battery.c
@@ -178,12 +178,6 @@ static int wm97xx_bat_probe(struct platform_device *dev)
 				     "failed to get charge GPIO\n");
 	if (charge_gpiod) {
 		gpiod_set_consumer_name(charge_gpiod, "BATT CHRG");
-		ret = request_irq(gpiod_to_irq(charge_gpiod),
-				wm97xx_chrg_irq, 0,
-				"AC Detect", dev);
-		if (ret)
-			return dev_err_probe(&dev->dev, ret,
-					     "failed to request GPIO irq\n");
 		props++;	/* POWER_SUPPLY_PROP_STATUS */
 	}
 
@@ -199,10 +193,8 @@ static int wm97xx_bat_probe(struct platform_device *dev)
 		props++;	/* POWER_SUPPLY_PROP_VOLTAGE_MIN */
 
 	prop = kcalloc(props, sizeof(*prop), GFP_KERNEL);
-	if (!prop) {
-		ret = -ENOMEM;
-		goto err3;
-	}
+	if (!prop)
+		return -ENOMEM;
 
 	prop[i++] = POWER_SUPPLY_PROP_PRESENT;
 	if (charge_gpiod)
@@ -236,15 +228,27 @@ static int wm97xx_bat_probe(struct platform_device *dev)
 		schedule_work(&bat_work);
 	} else {
 		ret = PTR_ERR(bat_psy);
-		goto err4;
+		goto free;
+	}
+
+	if (charge_gpiod) {
+		ret = request_irq(gpiod_to_irq(charge_gpiod), wm97xx_chrg_irq,
+				  0, "AC Detect", dev);
+		if (ret) {
+			dev_err_probe(&dev->dev, ret,
+				      "failed to request GPIO irq\n");
+			goto unregister;
+		}
 	}
 
 	return 0;
-err4:
+
+unregister:
+	power_supply_unregister(bat_psy);
+
+free:
 	kfree(prop);
-err3:
-	if (charge_gpiod)
-		free_irq(gpiod_to_irq(charge_gpiod), dev);
+
 	return ret;
 }
 
-- 
2.39.5