{"id":"CVE-2026-80818","title":"iommu/tegra241-cmdqv: Fix CMD_SYNC use-after-free on teardown","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/tegra241-cmdqv: Fix CMD_SYNC use-after-free on teardown\n\narm_smmu_impl_remove() is registered as a devres action in\narm_smmu_impl_probe(), before arm_smmu_init_qu…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 < d2ab08437e913d9e4dda4dfd0d327446ec8717fc","Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 < a94309bb99eaf0c6a2ace4927864486d19458eb5","Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 < 5994617e09ee6016c1b094f29d9c85cac944b477","Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 < 9ff145a25c5c8a26b06ef7cf558fb536b18bba6d","Linux 6.17"],"published":"2026-09-04","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:44:11.934Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80818","references":[{"url":"https://git.kernel.org/stable/c/d2ab08437e913d9e4dda4dfd0d327446ec8717fc"},{"url":"https://git.kernel.org/stable/c/a94309bb99eaf0c6a2ace4927864486d19458eb5"},{"url":"https://git.kernel.org/stable/c/5994617e09ee6016c1b094f29d9c85cac944b477"},{"url":"https://git.kernel.org/stable/c/9ff145a25c5c8a26b06ef7cf558fb536b18bba6d"}],"tags":["cve.org"],"epss":0.00209,"epssPercentile":0.10314,"ingestedAt":"2026-10-19T09:16:01.505Z","slug":"CVE-2026-80818","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\niommu/tegra241-cmdqv: Fix CMD_SYNC use-after-free on teardown\n\narm_smmu_impl_remove() is registered as a devres action in\narm_smmu_impl_probe(), before arm_smmu_init_queues() allocates\nsmmu->cmdq.q.base. On a devres unwind, whether a failed probe or an\nunbind, the queue is freed first and arm_smmu_impl_remove() then runs\ntegra241_cmdqv_remove_vintf(), whose VINTF deinit issues a CMD_SYNC on\nthe freed memory.\n\nObserved during testing with a QEMU hack that makes the VCMDQ fail to\nenable, so the impl reset fails and probe aborts into the devres unwind:\n\n platform NVDA200C:00: tegra241_cmdqv: VINTF0: VCMDQ0/LVCMDQ0: failed to enable, STATUS=0x00000000\n platform NVDA200C:00: tegra241_cmdqv: VINTF0: VCMDQ0/LVCMDQ0: GERRORN=0x0, GERROR=0x4, CONS=0x0\n platform NVDA200C:00: tegra241_cmdqv: VINTF0: VCMDQ0/LVCMDQ0: uncleared error detected, resetting\n arm-smmu-v3 arm-smmu-v3.0.auto: failed to reset impl\n arm-smmu-v3 arm-smmu-v3.0.auto: probe with driver arm-smmu-v3 failed with error -110\n Unable to handle kernel paging request at virtual address ffff8000891e0098\n ...\n Internal error: Oops: 0000000096000047 [#1] SMP\n ...\n Call trace:\n  arm_smmu_cmdq_issue_cmdlist+0x320/0x6fc (P)\n  tegra241_vcmdq_hw_deinit+0x98/0x168\n  tegra241_vintf_hw_deinit+0x5c/0x1b0\n  tegra241_cmdqv_remove_vintf+0x34/0xec\n  tegra241_cmdqv_remove+0x40/0x9c\n  arm_smmu_impl_remove+0x20/0x30\n  devm_action_release+0x14/0x20\n  devres_release_all+0xa8/0x110\n  device_unbind_cleanup+0x18/0x84\n  really_probe+0x1f0/0x29c\n\nDrop the VINTF deinit from tegra241_cmdqv_remove_vintf() so the unwind no\nlonger touches the freed queue. Quiesce the VINTFs earlier instead. Add a\ndevice_disable() impl op and run it from arm_smmu_disable_action() while\nthe CMDQ is still up. That handles a live unbind. A failed reset is already\nhandled because tegra241_vintf_hw_init() deinits the VINTF on its own error\npath. tegra241_cmdqv_remove_vintf() is also used by the iommufd viommu\ndestroy path, so quiesce there too.\n\n## Affected\n\n- `Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 < d2ab08437e913d9e4dda4dfd0d327446ec8717fc`\n- `Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 < a94309bb99eaf0c6a2ace4927864486d19458eb5`\n- `Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 < 5994617e09ee6016c1b094f29d9c85cac944b477`\n- `Linux >= 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7 < 9ff145a25c5c8a26b06ef7cf558fb536b18bba6d`\n- `Linux 6.17`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}