Messages in this thread Patch in this message | | | From | Xiyu Yang <> | Subject | [PATCH] iommu/arm-smmu: Fix arm_smmu_device refcount leak when arm_smmu_rpm_get fails | Date | Wed, 9 Jun 2021 21:35:07 +0800 |
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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 arm_smmu_rpm_put() or jumping to the "rpm_put" label when arm_smmu_rpm_get() fails.
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> --- drivers/iommu/arm/arm-smmu/arm-smmu.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index 6f72c4d208ca..177ee54c5534 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -840,7 +840,7 @@ static void arm_smmu_destroy_domain_context(struct iommu_domain *domain) ret = arm_smmu_rpm_get(smmu); if (ret < 0) - return; + goto rpm_put; /* * Disable the context bank and free the page tables before freeing @@ -857,6 +857,7 @@ static void arm_smmu_destroy_domain_context(struct iommu_domain *domain) free_io_pgtable_ops(smmu_domain->pgtbl_ops); __arm_smmu_free_bitmap(smmu->context_map, cfg->cbndx); +rpm_put: arm_smmu_rpm_put(smmu); } @@ -1153,7 +1154,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) ret = arm_smmu_rpm_get(smmu); if (ret < 0) - return ret; + goto rpm_put; /* Ensure that the domain is finalised */ ret = arm_smmu_init_domain_context(domain, smmu, dev); @@ -1404,7 +1405,7 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev) ret = arm_smmu_rpm_get(smmu); if (ret < 0) - goto out_cfg_free; + goto rpm_put; ret = arm_smmu_master_alloc_smes(dev); arm_smmu_rpm_put(smmu); @@ -1417,6 +1418,8 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev) return &smmu->iommu; +rpm_put: + arm_smmu_rpm_put(smmu); out_cfg_free: kfree(cfg); out_free: @@ -1438,8 +1441,10 @@ static void arm_smmu_release_device(struct device *dev) smmu = cfg->smmu; ret = arm_smmu_rpm_get(smmu); - if (ret < 0) + if (ret < 0) { + arm_smmu_rpm_put(smmu); return; + } arm_smmu_master_free_smes(cfg, fwspec); -- 2.7.4
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