[PATCH] iommu/arm-smmu: Fix arm_smmu_device refcount leak when arm_smmu_rpm_get fails
From: Xiyu Yang <hidden>
Date: 2021-06-09 13:36:30
Also in:
linux-iommu, lkml
Subsystem:
arm smmu drivers, iommu subsystem, the rest · Maintainers:
Will Deacon, Joerg Roedel, Linus Torvalds
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 <redacted> Signed-off-by: Xin Tan <redacted> --- 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
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel