| Message ID | 1623293391-17261-1-git-send-email-xiyuyang19@fudan.edu.cn (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] iommu/arm-smmu: Fix arm_smmu_device refcount leak in address translation | expand |
On Wed, Jun 9, 2021 at 7:50 PM Xiyu Yang <xiyuyang19@fudan.edu.cn> wrote: > > 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> > --- > 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 6f72c4d208ca..3a3847277320 100644 > --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c > +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c > @@ -1271,6 +1271,7 @@ 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) > @@ -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); I suppose you could also: addr = ops->iov_to_phys(...); goto out; but either way, Reviewed-by: Rob Clark <robdclark@chromium.org> > } > > @@ -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 >
On Thu, 10 Jun 2021 10:49:20 +0800, Xiyu Yang wrote: > 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. Applied to will (for-joerg/arm-smmu/updates), thanks! [1/1] iommu/arm-smmu: Fix arm_smmu_device refcount leak in address translation https://git.kernel.org/will/c/7c8f176d6a3f Cheers,
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index 6f72c4d208ca..3a3847277320 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -1271,6 +1271,7 @@ 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) @@ -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,