From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	Ricardo Neri <ricardo.neri-calderon@linux.intel.com>,
	"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.1 0589/1067] thermal: intel: Fix dangling resources on thermal_throttle_online() failure
Date: Tue, 21 Jul 2026 17:19:50 +0200
Message-ID: <20260721152437.782138995@linuxfoundation.org>
In-Reply-To: <20260721152424.521567757@linuxfoundation.org>
References: <20260721152424.521567757@linuxfoundation.org>
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6.1-stable review patch.  If anyone has any objections, please let me know.

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

From: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>

[ Upstream commit b91d287fa7a1ba0727eed5823c6ee4924ee5fa31 ]

The function thermal_throttle_add_dev() may fail and abort a CPU hotplug
online operation. Since the failure occurs within the online callback,
thermal_throttle_online(), the CPU hotplug framework does not invoke the
corresponding offline callback. As a result, the hardware and software
resources set up during the failed operation are not torn down.

Since only thermal_throttle_add_dev() can fail, call it before setting up
the rest of the resources.

Fixes: f6656208f04e ("x86/mce/therm_throt: Optimize notifications of thermal throttle")
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Link: https://patch.msgid.link/20260613-rneri-directed-therm-intr-v3-1-3a26d1e47fc8@linux.intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/thermal/intel/therm_throt.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/intel/therm_throt.c b/drivers/thermal/intel/therm_throt.c
index 8352083b87c7cd..0be73a2afe73b9 100644
--- a/drivers/thermal/intel/therm_throt.c
+++ b/drivers/thermal/intel/therm_throt.c
@@ -468,8 +468,13 @@ static int thermal_throttle_online(unsigned int cpu)
 {
 	struct thermal_state *state = &per_cpu(thermal_state, cpu);
 	struct device *dev = get_cpu_device(cpu);
+	int err;
 	u32 l;
 
+	err = thermal_throttle_add_dev(dev, cpu);
+	if (err)
+		return err;
+
 	state->package_throttle.level = PACKAGE_LEVEL;
 	state->core_throttle.level = CORE_LEVEL;
 
@@ -487,7 +492,7 @@ static int thermal_throttle_online(unsigned int cpu)
 	l = apic_read(APIC_LVTTHMR);
 	apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
 
-	return thermal_throttle_add_dev(dev, cpu);
+	return err;
 }
 
 static int thermal_throttle_offline(unsigned int cpu)
-- 
2.53.0