In the Linux kernel, the following vulnerability has been resolved:
iommu/amd: Fix IRQ unsafe locking in gdom allocation
Lockdep complains:
[ 259.410489] =====================================================
[ 259.417287] WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
[ 259.424667] 7.0.0-g51db1d8d2113 #54 Not tainted
[ 259.429718] -----------------------------------------------------
[ 259.436516] qemu-system-x86/10143 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
[ 259.444670] ff3b2b1c60305170 (&xa->xa_lock#25){+.+.}-{3:3}, at: __domain_flush_pages+0x17c/0x4b0
[ 259.454485]
and this task is already holding:
[ 259.460991] ff3b2b1c98504cc0 (&domain->lock){-.-.}-{3:3}, at: amd_iommu_iotlb_sync+0x25/0x60
[ 259.470408] which would create a new lock dependency:
[ 259.476041] (&domain->lock){-.-.}-{3:3} -> (&xa->xa_lock#25){+.+.}-{3:3}
[ 259.483615]
but this new dependency connects a HARDIRQ-irq-safe lock:
[ 259.492447] (&domain->lock){-.-.}-{3:3}
[ 259.492449]
... which became HARDIRQ-irq-safe at:
[ 259.503705] lock_acquire+0xb6/0x2e0
[ 259.507790] _raw_spin_lock_irqsave+0x3e/0x60
[ 259.512748] amd_iommu_flush_iotlb_all+0x20/0x50
[ 259.517996] iommu_dma_free_iova.isra.0+0x1b8/0x1e0
[ 259.523534] __iommu_dma_unmap+0xc2/0x140
[ 259.528100] iommu_dma_unmap_phys+0x55/0xc0
[ 259.532863] dma_unmap_phys+0x274/0x2e0
[ 259.537238] dma_unmap_page_attrs+0x17/0x30
[ 259.542000] nvme_unmap_data+0x13e/0x280
[ 259.546473] nvme_pci_complete_batch+0x45/0x70
[ 259.551524] nvme_irq+0x83/0x90
[ 259.555123] __handle_irq_event_percpu+0x92/0x360
[ 259.560466] handle_irq_event+0x39/0x80
[ 259.564841] handle_edge_irq+0xb2/0x1a0
[ 259.569214] __common_interrupt+0x4e/0x130
[ 259.573882] common_interrupt+0x88/0xa0
[ 259.578256] asm_common_interrupt+0x27/0x40
[ 259.583019] cpuidle_enter_state+0x119/0x5d0
[ 259.587877] cpuidle_enter+0x2e/0x50
[ 259.591962] do_idle+0x153/0x2c0
[ 259.595657] cpu_startup_entry+0x29/0x30
[ 259.600128] start_secondary+0x118/0x150
[ 259.604601] common_startup_64+0x13e/0x141
[ 259.609266]
to a HARDIRQ-irq-unsafe lock:
[ 259.615384] (&xa->xa_lock#25){+.+.}-{3:3}
[ 259.615386]
... which became HARDIRQ-irq-unsafe at:
[ 259.627039] ...
[ 259.627039] lock_acquire+0xb6/0x2e0
[ 259.633071] _raw_spin_lock+0x2f/0x50
[ 259.637250] amd_iommu_alloc_domain_nested+0x140/0x3c0
[ 259.643078] iommufd_hwpt_alloc+0x272/0x800 [iommufd]
[ 259.648813] iommufd_fops_ioctl+0x14e/0x200 [iommufd]
[ 259.654547] __x64_sys_ioctl+0x9d/0xf0
...
Since amd_iommu_domain_flush_pages() necessarily holds domain->lock to do the
flush, switch the allocation side in gdom_info_load_or_alloc_locked() to
HARDIRQ-safe allocation. The IOMMU_DESTROY->free path has the same issue,
so switch that path to HARDIRQ-safe locking as well.
iommu/amd: Fix IRQ unsafe locking in gdom allocation
Lockdep complains:
[ 259.410489] =====================================================
[ 259.417287] WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
[ 259.424667] 7.0.0-g51db1d8d2113 #54 Not tainted
[ 259.429718] -----------------------------------------------------
[ 259.436516] qemu-system-x86/10143 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
[ 259.444670] ff3b2b1c60305170 (&xa->xa_lock#25){+.+.}-{3:3}, at: __domain_flush_pages+0x17c/0x4b0
[ 259.454485]
and this task is already holding:
[ 259.460991] ff3b2b1c98504cc0 (&domain->lock){-.-.}-{3:3}, at: amd_iommu_iotlb_sync+0x25/0x60
[ 259.470408] which would create a new lock dependency:
[ 259.476041] (&domain->lock){-.-.}-{3:3} -> (&xa->xa_lock#25){+.+.}-{3:3}
[ 259.483615]
but this new dependency connects a HARDIRQ-irq-safe lock:
[ 259.492447] (&domain->lock){-.-.}-{3:3}
[ 259.492449]
... which became HARDIRQ-irq-safe at:
[ 259.503705] lock_acquire+0xb6/0x2e0
[ 259.507790] _raw_spin_lock_irqsave+0x3e/0x60
[ 259.512748] amd_iommu_flush_iotlb_all+0x20/0x50
[ 259.517996] iommu_dma_free_iova.isra.0+0x1b8/0x1e0
[ 259.523534] __iommu_dma_unmap+0xc2/0x140
[ 259.528100] iommu_dma_unmap_phys+0x55/0xc0
[ 259.532863] dma_unmap_phys+0x274/0x2e0
[ 259.537238] dma_unmap_page_attrs+0x17/0x30
[ 259.542000] nvme_unmap_data+0x13e/0x280
[ 259.546473] nvme_pci_complete_batch+0x45/0x70
[ 259.551524] nvme_irq+0x83/0x90
[ 259.555123] __handle_irq_event_percpu+0x92/0x360
[ 259.560466] handle_irq_event+0x39/0x80
[ 259.564841] handle_edge_irq+0xb2/0x1a0
[ 259.569214] __common_interrupt+0x4e/0x130
[ 259.573882] common_interrupt+0x88/0xa0
[ 259.578256] asm_common_interrupt+0x27/0x40
[ 259.583019] cpuidle_enter_state+0x119/0x5d0
[ 259.587877] cpuidle_enter+0x2e/0x50
[ 259.591962] do_idle+0x153/0x2c0
[ 259.595657] cpu_startup_entry+0x29/0x30
[ 259.600128] start_secondary+0x118/0x150
[ 259.604601] common_startup_64+0x13e/0x141
[ 259.609266]
to a HARDIRQ-irq-unsafe lock:
[ 259.615384] (&xa->xa_lock#25){+.+.}-{3:3}
[ 259.615386]
... which became HARDIRQ-irq-unsafe at:
[ 259.627039] ...
[ 259.627039] lock_acquire+0xb6/0x2e0
[ 259.633071] _raw_spin_lock+0x2f/0x50
[ 259.637250] amd_iommu_alloc_domain_nested+0x140/0x3c0
[ 259.643078] iommufd_hwpt_alloc+0x272/0x800 [iommufd]
[ 259.648813] iommufd_fops_ioctl+0x14e/0x200 [iommufd]
[ 259.654547] __x64_sys_ioctl+0x9d/0xf0
...
Since amd_iommu_domain_flush_pages() necessarily holds domain->lock to do the
flush, switch the allocation side in gdom_info_load_or_alloc_locked() to
HARDIRQ-safe allocation. The IOMMU_DESTROY->free path has the same issue,
so switch that path to HARDIRQ-safe locking as well.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Mon, 10 Aug 2026 12:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: iommu/amd: Fix IRQ unsafe locking in gdom allocation Lockdep complains: [ 259.410489] ===================================================== [ 259.417287] WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected [ 259.424667] 7.0.0-g51db1d8d2113 #54 Not tainted [ 259.429718] ----------------------------------------------------- [ 259.436516] qemu-system-x86/10143 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: [ 259.444670] ff3b2b1c60305170 (&xa->xa_lock#25){+.+.}-{3:3}, at: __domain_flush_pages+0x17c/0x4b0 [ 259.454485] and this task is already holding: [ 259.460991] ff3b2b1c98504cc0 (&domain->lock){-.-.}-{3:3}, at: amd_iommu_iotlb_sync+0x25/0x60 [ 259.470408] which would create a new lock dependency: [ 259.476041] (&domain->lock){-.-.}-{3:3} -> (&xa->xa_lock#25){+.+.}-{3:3} [ 259.483615] but this new dependency connects a HARDIRQ-irq-safe lock: [ 259.492447] (&domain->lock){-.-.}-{3:3} [ 259.492449] ... which became HARDIRQ-irq-safe at: [ 259.503705] lock_acquire+0xb6/0x2e0 [ 259.507790] _raw_spin_lock_irqsave+0x3e/0x60 [ 259.512748] amd_iommu_flush_iotlb_all+0x20/0x50 [ 259.517996] iommu_dma_free_iova.isra.0+0x1b8/0x1e0 [ 259.523534] __iommu_dma_unmap+0xc2/0x140 [ 259.528100] iommu_dma_unmap_phys+0x55/0xc0 [ 259.532863] dma_unmap_phys+0x274/0x2e0 [ 259.537238] dma_unmap_page_attrs+0x17/0x30 [ 259.542000] nvme_unmap_data+0x13e/0x280 [ 259.546473] nvme_pci_complete_batch+0x45/0x70 [ 259.551524] nvme_irq+0x83/0x90 [ 259.555123] __handle_irq_event_percpu+0x92/0x360 [ 259.560466] handle_irq_event+0x39/0x80 [ 259.564841] handle_edge_irq+0xb2/0x1a0 [ 259.569214] __common_interrupt+0x4e/0x130 [ 259.573882] common_interrupt+0x88/0xa0 [ 259.578256] asm_common_interrupt+0x27/0x40 [ 259.583019] cpuidle_enter_state+0x119/0x5d0 [ 259.587877] cpuidle_enter+0x2e/0x50 [ 259.591962] do_idle+0x153/0x2c0 [ 259.595657] cpu_startup_entry+0x29/0x30 [ 259.600128] start_secondary+0x118/0x150 [ 259.604601] common_startup_64+0x13e/0x141 [ 259.609266] to a HARDIRQ-irq-unsafe lock: [ 259.615384] (&xa->xa_lock#25){+.+.}-{3:3} [ 259.615386] ... which became HARDIRQ-irq-unsafe at: [ 259.627039] ... [ 259.627039] lock_acquire+0xb6/0x2e0 [ 259.633071] _raw_spin_lock+0x2f/0x50 [ 259.637250] amd_iommu_alloc_domain_nested+0x140/0x3c0 [ 259.643078] iommufd_hwpt_alloc+0x272/0x800 [iommufd] [ 259.648813] iommufd_fops_ioctl+0x14e/0x200 [iommufd] [ 259.654547] __x64_sys_ioctl+0x9d/0xf0 ... Since amd_iommu_domain_flush_pages() necessarily holds domain->lock to do the flush, switch the allocation side in gdom_info_load_or_alloc_locked() to HARDIRQ-safe allocation. The IOMMU_DESTROY->free path has the same issue, so switch that path to HARDIRQ-safe locking as well. | |
| Title | iommu/amd: Fix IRQ unsafe locking in gdom allocation | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
Sign in to view the affected projects.
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-10T12:03:24.020Z
Reserved: 2026-07-30T09:28:09.384Z
Link: CVE-2026-68347
Vulnrichment
No data.
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.