| Message ID | 20250305211800.229465-1-nicolinc@nvidia.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | iommufd: Set domain->iommufd_hwpt in all hwpt->domain allocators | expand |
> From: Nicolin Chen <nicolinc@nvidia.com> > Sent: Thursday, March 6, 2025 5:18 AM > > Setting domain->iommufd_hwpt in iommufd_hwpt_alloc() only covers the > HWPT > allocations from user space, but not for an auto domain. This resulted in > a NULL pointer access in the auto domain pathway: > Unable to handle kernel NULL pointer dereference at > virtual address 0000000000000008 > pc : iommufd_sw_msi+0x54/0x2b0 > lr : iommufd_sw_msi+0x40/0x2b0 > Call trace: > iommufd_sw_msi+0x54/0x2b0 (P) > iommu_dma_prepare_msi+0x64/0xa8 > its_irq_domain_alloc+0xf0/0x2c0 > irq_domain_alloc_irqs_parent+0x2c/0xa8 > msi_domain_alloc+0xa0/0x1a8 > > Since iommufd_sw_msi() requires to access the domain->iommufd_hwpt, it > is > better to set that explicitly prior to calling iommu_domain_set_sw_msi(). > > Fixes: 748706d7ca06 ("iommu: Turn fault_data to iommufd private pointer") > Reported-by: Ankit Agrawal <ankita@nvidia.com> > Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com>
>> Since iommufd_sw_msi() requires to access the domain->iommufd_hwpt, it >> is >> better to set that explicitly prior to calling iommu_domain_set_sw_msi(). >> >> Fixes: 748706d7ca06 ("iommu: Turn fault_data to iommufd private pointer") >> Reported-by: Ankit Agrawal <ankita@nvidia.com> >> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> > > Reviewed-by: Kevin Tian <kevin.tian@intel.com> Tested-by: Ankit Agrawal <ankita@nvidia.com>
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c index 268315b1d8bc..1d4cfe3677dc 100644 --- a/drivers/iommu/iommufd/hw_pagetable.c +++ b/drivers/iommu/iommufd/hw_pagetable.c @@ -159,6 +159,7 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, goto out_abort; } } + hwpt->domain->iommufd_hwpt = hwpt; iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi); /* @@ -255,6 +256,7 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx, goto out_abort; } hwpt->domain->owner = ops; + hwpt->domain->iommufd_hwpt = hwpt; iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi); if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED)) { @@ -311,6 +313,7 @@ iommufd_viommu_alloc_hwpt_nested(struct iommufd_viommu *viommu, u32 flags, hwpt->domain = NULL; goto out_abort; } + hwpt->domain->iommufd_hwpt = hwpt; hwpt->domain->owner = viommu->iommu_dev->ops; iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi); @@ -415,7 +418,6 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) refcount_inc(&fault->obj.users); iommufd_put_object(ucmd->ictx, &fault->obj); } - hwpt->domain->iommufd_hwpt = hwpt; cmd->out_hwpt_id = hwpt->obj.id; rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
Setting domain->iommufd_hwpt in iommufd_hwpt_alloc() only covers the HWPT allocations from user space, but not for an auto domain. This resulted in a NULL pointer access in the auto domain pathway: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 pc : iommufd_sw_msi+0x54/0x2b0 lr : iommufd_sw_msi+0x40/0x2b0 Call trace: iommufd_sw_msi+0x54/0x2b0 (P) iommu_dma_prepare_msi+0x64/0xa8 its_irq_domain_alloc+0xf0/0x2c0 irq_domain_alloc_irqs_parent+0x2c/0xa8 msi_domain_alloc+0xa0/0x1a8 Since iommufd_sw_msi() requires to access the domain->iommufd_hwpt, it is better to set that explicitly prior to calling iommu_domain_set_sw_msi(). Fixes: 748706d7ca06 ("iommu: Turn fault_data to iommufd private pointer") Reported-by: Ankit Agrawal <ankita@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> --- drivers/iommu/iommufd/hw_pagetable.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)