# CVE-2026-68347: linux: In the Linux kernel, the following vulnerability has been resolved:  iommu/amd: Fix IRQ unsafe locking in gdom alloca...

CVE-2026-68347 is fixed in linux on 1 platform by DEBIAN-CVE-2026-68347 (version 7.1.6-1), released August 11, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-68347
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0016
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 10, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 7.1.6-1 | [DEBIAN-CVE-2026-68347](https://patchblox.com/security/data/fix/linux/debian-cve-2026-68347.md) | Aug 11, 2026 |

---

Data as of 2026-11-10T07:50:38Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.