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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn>,
	Xin Tan <tanxin.ctf@gmail.com>, Will Deacon <will@kernel.org>,
	Sasha Levin <sashal@kernel.org>,
	linux-arm-kernel@lists.infradead.org,
	iommu@lists.linux-foundation.org
Subject: [PATCH AUTOSEL 5.13 065/114] iommu/arm-smmu: Fix arm_smmu_device refcount leak when arm_smmu_rpm_get fails
Date: Fri,  9 Jul 2021 22:16:59 -0400	[thread overview]
Message-ID: <20210710021748.3167666-65-sashal@kernel.org> (raw)
In-Reply-To: <20210710021748.3167666-1-sashal@kernel.org>

From: Xiyu Yang <xiyuyang19@fudan.edu.cn>

[ Upstream commit 1adf30f198c26539a62d761e45af72cde570413d ]

arm_smmu_rpm_get() invokes pm_runtime_get_sync(), which increases the
refcount of the "smmu" even though the return value is less than 0.

The reference counting issue happens in some error handling paths of
arm_smmu_rpm_get() in its caller functions. When arm_smmu_rpm_get()
fails, the caller functions forget to decrease the refcount of "smmu"
increased by arm_smmu_rpm_get(), causing a refcount leak.

Fix this issue by calling pm_runtime_resume_and_get() instead of
pm_runtime_get_sync() in arm_smmu_rpm_get(), which can keep the refcount
balanced in case of failure.

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Link: https://lore.kernel.org/r/1623293672-17954-1-git-send-email-xiyuyang19@fudan.edu.cn
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/arm/arm-smmu/arm-smmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 6f72c4d208ca..ee6cac9e7c02 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -74,7 +74,7 @@ static bool using_legacy_binding, using_generic_binding;
 static inline int arm_smmu_rpm_get(struct arm_smmu_device *smmu)
 {
 	if (pm_runtime_enabled(smmu->dev))
-		return pm_runtime_get_sync(smmu->dev);
+		return pm_runtime_resume_and_get(smmu->dev);
 
 	return 0;
 }
-- 
2.30.2


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  parent reply	other threads:[~2021-07-10  2:21 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20210710021748.3167666-1-sashal@kernel.org>
2021-07-10  2:16 ` [PATCH AUTOSEL 5.13 024/114] usb: common: usb-conn-gpio: fix NULL pointer dereference of charger Sasha Levin
2021-07-10  2:16 ` [PATCH AUTOSEL 5.13 051/114] mfd: da9052/stmpe: Add and modify MODULE_DEVICE_TABLE Sasha Levin
2021-07-10  2:16 ` [PATCH AUTOSEL 5.13 056/114] fsi: Add missing MODULE_DEVICE_TABLE Sasha Levin
2021-07-10  2:16 ` [PATCH AUTOSEL 5.13 061/114] iommu/arm-smmu-qcom: Skip the TTBR1 quirk for db820c Sasha Levin
2021-07-10  2:16 ` Sasha Levin [this message]
2021-07-10  2:17 ` [PATCH AUTOSEL 5.13 066/114] iommu/arm-smmu: Fix arm_smmu_device refcount leak in address translation Sasha Levin
2021-07-10  2:17 ` [PATCH AUTOSEL 5.13 070/114] gpio: zynq: Check return value of pm_runtime_get_sync Sasha Levin
2021-07-10  2:17 ` [PATCH AUTOSEL 5.13 071/114] gpio: zynq: Check return value of irq_get_irq_data Sasha Levin

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