kernel/git/next/linux-next.git/drivers/iommu/io-pgfault.c, branch master

iommu/iommufd: Fix IOPF group ownership UAF

2026-07-26T16:16:21+00:00

iopf_group_alloc() links each last-page IOPF group into the generic IOPF pending list before invoking the domain fault handler. iommufd_fault_iopf_handler() also queued an accepted group in the IOMMUFD deliver list without removing it from the generic pending list. When detach or HWPT replacement drops the device's IOPF reference count to zero, an IOMMU driver may call iopf_queue_remove_device(). That function responds to and frees groups through the generic pending list without removing the same groups from IOMMUFD's deliver list or response xarray. A later read, response, or cleanup can then access the freed group and cause a UAF. Fix this by dequeuing an accepted group from the generic pending list before IOMMUFD queues it for userspace response. Make iopf_group_response() send a response regardless of pending-list membership, so the dequeued group can still be completed by IOMMUFD. Link: https://patch.msgid.link/r/3CFD314D0FE4D7EC+20260720085017.3998878-2-peiyang_he@smail.nju.edu.cn Closes: https://lore.kernel.org/all/B4F28798E2E784CA+d29f723c-b2b5-4b67-8d1c-4f7b9b0b27cb@smail.nju.edu.cn/ Fixes: 34765cbc679c ("iommufd: Associate fault object with iommufd_hw_pgtable") Cc: stable@vger.kernel.org Tested-by: Peiyang He Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Peiyang He Reviewed-by: Kevin Tian Signed-off-by: Jason Gunthorpe

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

iommu: Fix potential memory leak in iopf_queue_remove_device()

2025-02-10T13:49:30+00:00

The iopf_queue_remove_device() helper removes a device from the per-iommu iopf queue when PRI is disabled on the device. It responds to all outstanding iopf's with an IOMMU_PAGE_RESP_INVALID code and detaches the device from the queue. However, it fails to release the group structure that represents a group of iopf's awaiting for a response after responding to the hardware. This can cause a memory leak if iopf_queue_remove_device() is called with pending iopf's. Fix it by calling iopf_free_group() after the iopf group is responded. Fixes: 199112327135 ("iommu: Track iopf group instead of last fault") Cc: stable@vger.kernel.org Suggested-by: Kevin Tian Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20250117055800.782462-1-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel

iommu: Handle iommu faults for a bad iopf setup

2024-08-23T09:16:39+00:00

The iommu_report_device_fault function was updated to return void while assuming that drivers only need to call iommu_report_device_fault() for reporting an iopf. This implementation causes following problems: 1. The drivers rely on the core code to call it's page_reponse, however, when a fault is received and no fault capable domain is attached / iopf_param is NULL, the ops->page_response is NOT called causing the device to stall in case the fault type was PAGE_REQ. 2. The arm_smmu_v3 driver relies on the returned value to log errors returning void from iommu_report_device_fault causes these events to be missed while logging. Modify the iommu_report_device_fault function to return -EINVAL for cases where no fault capable domain is attached or iopf_param was NULL and calls back to the driver (ops->page_response) in case the fault type was IOMMU_FAULT_PAGE_REQ. The returned value can be used by the drivers to log the fault/event as needed. Reported-by: Kunkun Jiang Closes: https://lore.kernel.org/all/6147caf0-b9a0-30ca-795e-a1aa502a5c51@huawei.com/ Fixes: 3dfa64aecbaf ("iommu: Make iommu_report_device_fault() return void") Signed-off-by: Jason Gunthorpe Signed-off-by: Pranjal Shrivastava Reviewed-by: Jason Gunthorpe Reviewed-by: Lu Baolu Link: https://lore.kernel.org/r/20240816104906.1010626-1-praan@google.com Signed-off-by: Joerg Roedel

iommu: Restore lost return in iommu_report_device_fault()

2024-08-02T13:58:05+00:00

When iommu_report_device_fault gets called with a partial fault it is supposed to collect the fault into the group and then return. Instead the return was accidently deleted which results in trying to process the fault and an eventual crash. Deleting the return was a typo, put it back. Fixes: 3dfa64aecbaf ("iommu: Make iommu_report_device_fault() return void") Signed-off-by: Barak Biber Signed-off-by: Jason Gunthorpe Reviewed-by: Lu Baolu Link: https://lore.kernel.org/r/0-v1-e7153d9c8cee+1c6-iommu_fault_fix_jgg@nvidia.com Signed-off-by: Joerg Roedel

iommufd: Add iommufd fault object

2024-07-09T16:54:32+00:00

An iommufd fault object provides an interface for delivering I/O page faults to user space. These objects are created and destroyed by user space, and they can be associated with or dissociated from hardware page table objects during page table allocation or destruction. User space interacts with the fault object through a file interface. This interface offers a straightforward and efficient way for user space to handle page faults. It allows user space to read fault messages sequentially and respond to them by writing to the same file. The file interface supports reading messages in poll mode, so it's recommended that user space applications use io_uring to enhance read and write efficiency. A fault object can be associated with any iopf-capable iommufd_hw_pgtable during the pgtable's allocation. All I/O page faults triggered by devices when accessing the I/O addresses of an iommufd_hw_pgtable are routed through the fault object to user space. Similarly, user space's responses to these page faults are routed back to the iommu device driver through the same fault object. Link: https://lore.kernel.org/r/20240702063444.105814-7-baolu.lu@linux.intel.com Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Signed-off-by: Jason Gunthorpe

iommu: Add attach handle to struct iopf_group

2024-07-04T12:46:18+00:00

Previously, the domain that a page fault targets is stored in an iopf_group, which represents a minimal set of page faults. With the introduction of attach handle, replace the domain with the handle so that the fault handler can obtain more information as needed when handling the faults. iommu_report_device_fault() is currently used for SVA page faults, which handles the page fault in an internal cycle. The domain is retrieved with iommu_get_domain_for_dev_pasid() if the pasid in the fault message is valid. This doesn't work in IOMMUFD case, where if the pasid table of a device is wholly managed by user space, there is no domain attached to the PASID of the device, and all page faults are forwarded through a NESTING domain attaching to RID. Add a static flag in iommu ops, which indicates if the IOMMU driver supports user-managed PASID tables. In the iopf deliver path, if no attach handle found for the iopf PASID, roll back to RID domain when the IOMMU driver supports this capability. iommu_get_domain_for_dev_pasid() is no longer used and can be removed. Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20240702063444.105814-4-baolu.lu@linux.intel.com Signed-off-by: Will Deacon

iommu: Make iommu_report_device_fault() return void

2024-02-16T14:19:37+00:00

As the iommu_report_device_fault() has been converted to auto-respond a page fault if it fails to enqueue it, there's no need to return a code in any case. Make it return void. Suggested-by: Jason Gunthorpe Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20240212012227.119381-17-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel

iommu: Make iopf_group_response() return void

2024-02-16T14:19:36+00:00

The iopf_group_response() should return void, as nothing can do anything with the failure. This implies that ops->page_response() must also return void; this is consistent with what the drivers do. The failure paths, which are all integrity validations of the fault, should be WARN_ON'd, not return codes. If the iommu core fails to enqueue the fault, it should respond the fault directly by calling ops->page_response() instead of returning an error number and relying on the iommu drivers to do so. Consolidate the error fault handling code in the core. Co-developed-by: Jason Gunthorpe Signed-off-by: Jason Gunthorpe Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20240212012227.119381-16-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel