[PATCH AUTOSEL 5.10 57/93] iommu/arm-smmu: Fix arm_smmu_device refcount leak in address translation
From: Sasha Levin <sashal@kernel.org>
Date: 2021-07-10 02:29:39
Also in:
linux-arm-kernel, linux-iommu, lkml
Subsystem:
arm smmu drivers, iommu subsystem, the rest · Maintainers:
Will Deacon, Joerg Roedel, Linus Torvalds
From: Xiyu Yang <redacted> [ Upstream commit 7c8f176d6a3fa18aa0f8875da6f7c672ed2a8554 ] The reference counting issue happens in several exception handling paths of arm_smmu_iova_to_phys_hard(). When those error scenarios occur, the function forgets to decrease the refcount of "smmu" increased by arm_smmu_rpm_get(), causing a refcount leak. Fix this issue by jumping to "out" label when those error scenarios occur. Signed-off-by: Xiyu Yang <redacted> Signed-off-by: Xin Tan <redacted> Reviewed-by: Rob Clark <redacted> Link: https://lore.kernel.org/r/1623293391-17261-1-git-send-email-xiyuyang19@fudan.edu.cn (local) Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/iommu/arm/arm-smmu/arm-smmu.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 052f0a1bf037..df24bbe3ea4f 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c@@ -1284,6 +1284,7 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain, u64 phys; unsigned long va, flags; int ret, idx = cfg->cbndx; + phys_addr_t addr = 0; ret = arm_smmu_rpm_get(smmu); if (ret < 0)
@@ -1303,6 +1304,7 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain, dev_err(dev, "iova to phys timed out on %pad. Falling back to software table walk.\n", &iova); + arm_smmu_rpm_put(smmu); return ops->iova_to_phys(ops, iova); }
@@ -1311,12 +1313,14 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain, if (phys & ARM_SMMU_CB_PAR_F) { dev_err(dev, "translation fault!\n"); dev_err(dev, "PAR = 0x%llx\n", phys); - return 0; + goto out; } + addr = (phys & GENMASK_ULL(39, 12)) | (iova & 0xfff); +out: arm_smmu_rpm_put(smmu); - return (phys & GENMASK_ULL(39, 12)) | (iova & 0xfff); + return addr; } static phys_addr_t arm_smmu_iova_to_phys(struct iommu_domain *domain,
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2.30.2