[PATCH] iommu/arm-smmu: Fix arm_smmu_device refcount leak in address translation
From: Xiyu Yang <hidden>
Date: 2021-06-09 13:36:16
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 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> --- drivers/iommu/arm/arm-smmu/arm-smmu.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 6f72c4d208ca..023dcd72ed35 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c@@ -1271,10 +1271,11 @@ 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) - return 0; + goto out; spin_lock_irqsave(&smmu_domain->cb_lock, flags); va = iova & ~0xfffUL;
@@ -1290,6 +1291,7 @@ 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); }
@@ -1298,12 +1300,14 @@ 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,
--
2.7.4
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel