From: Xiyu Yang xiyuyang19@fudan.edu.cn
[ 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 xiyuyang19@fudan.edu.cn Signed-off-by: Xin Tan tanxin.ctf@gmail.com Reviewed-by: Rob Clark robdclark@chromium.org Link: https://lore.kernel.org/r/1623293391-17261-1-git-send-email-xiyuyang19@fudan... Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iommu/arm-smmu.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index abf4cf285548..2185ea5191c1 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -1231,6 +1231,7 @@ 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) @@ -1249,6 +1250,7 @@ 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); }
@@ -1257,12 +1259,14 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain, if (phys & 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,