CVE-2026-68347
iommu/amd: Fix IRQ unsafe locking in gdom allocation
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.
INFO
Published Date :
Aug. 10, 2026, 1:20 p.m.
Last Modified :
Aug. 17, 2026, 6:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to the latest stable version.
- Apply the provided patch for iommu/amd.
- Ensure all systems use a HARDIRQ-safe allocation strategy.
- Verify lock ordering in related IOMMU functions.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-68347.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/0db3a430d9681fdb29890bef6934cd89cd1745d0 | |
| https://git.kernel.org/stable/c/e0c78cdf35af3ada05f9309f4641e9f83c945dbd |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-68347 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-68347
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-68347 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-68347 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '757d2b1fdf5b7d6eead5963a49b5780617987ab8', 'lessThan': 'e0c78cdf35af3ada05f9309f4641e9f83c945dbd', 'versionType': 'git'}, {'status': 'affected', 'version': '757d2b1fdf5b7d6eead5963a49b5780617987ab8', 'lessThan': '0db3a430d9681fdb29890bef6934cd89cd1745d0', 'versionType': 'git'}], 'programFiles': ['drivers/iommu/amd/nested.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7.0'}, {'status': 'unaffected', 'version': '0', 'lessThan': '7.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.6', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc5', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/iommu/amd/nested.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '757d2b1fdf5b7d6eead5963a49b5780617987ab8', 'lessThan': 'e0c78cdf35af3ada05f9309f4641e9f83c945dbd', 'versionType': 'git'}, {'status': 'affected', 'version': '757d2b1fdf5b7d6eead5963a49b5780617987ab8', 'lessThan': '0db3a430d9681fdb29890bef6934cd89cd1745d0', 'versionType': 'git'}], 'programFiles': ['drivers/iommu/amd/nested.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7.0'}, {'status': 'unaffected', 'version': '0', 'lessThan': '7.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.6', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/iommu/amd/nested.c'], 'defaultStatus': 'affected'}] -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 10, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '757d2b1fdf5b7d6eead5963a49b5780617987ab8', 'lessThan': 'e0c78cdf35af3ada05f9309f4641e9f83c945dbd', 'versionType': 'git'}, {'status': 'affected', 'version': '757d2b1fdf5b7d6eead5963a49b5780617987ab8', 'lessThan': '0db3a430d9681fdb29890bef6934cd89cd1745d0', 'versionType': 'git'}], 'programFiles': ['drivers/iommu/amd/nested.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7.0'}, {'status': 'unaffected', 'version': '0', 'lessThan': '7.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.6', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc5', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/iommu/amd/nested.c'], 'defaultStatus': 'affected'}] 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. Added Reference https://git.kernel.org/stable/c/0db3a430d9681fdb29890bef6934cd89cd1745d0 Added Reference https://git.kernel.org/stable/c/e0c78cdf35af3ada05f9309f4641e9f83c945dbd