CVE-2026-90429 (GCVE-0-2026-90429)
Vulnerability from cvelistv5
Published
2026-09-17 16:09
Modified
2026-10-19 09:03
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: iommu/tegra241-cmdqv: Synchronize the error ISR against VINTF (de)init A user VINTF is torn down by tegra241_cmdqv_deinit_vintf(), which runs from the destroy callback and from the init-failure unwind in the alloc handler. It clears the cmdqv->vintfs[] slot and lets the iommufd core free it, but nothing serializes that against the error interrupt: tegra241_cmdqv_isr() reads cmdqv->vintfs[idx] and dereferences the vintf. A concurrent error can make the ISR read a slot mid-clear (a NULL deref) or use a vintf which is about to be freed (a use-after-free). deinit_vintf() also returns idx to the IDA before clearing the slot, so a concurrent create that reuses idx can publish its new vintf into the slot, only for this teardown to erase it again with the stale NULL store. On the other end, tegra241_cmdqv_init_vintf() publishes a new vintf with a plain store to the cmdqv->vintfs[] slot, and the ISR dereferences fields of a published vintf such as vintf->base. A plain store gives no ordering on a weakly-ordered CPU, and a stale VINTF_ERR_MAP bit on a reused idx can make the ISR pick a vintf the moment it is published, before its fields are set or tegra241_vintf_hw_init() runs. The cmdqv->vintfs[0] slot stays NULL until tegra241_cmdqv_init_structures() first creates VINTF0, so the slot 0 read needs the same NULL check. Publish every slot with an smp_store_release(), and read each slot in the ISR with an smp_load_acquire() under a NULL check, so the ISR always sees a fully built vintf or NULL. Also make deinit_vintf() clear the slot, and synchronize_irq() prior to returning idx to the IDA, so no vintf is freed under a running handler and no reused idx is clobbered.
References
Impacted products
Vendor Product Version
Linux Linux Version: 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7
Version: 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7
Version: 4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "bcb82407633c3008362ad927699d985ee4981557",
              "status": "affected",
              "version": "4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7",
              "versionType": "git"
            },
            {
              "lessThan": "f3ef4abc271a1d3d7b6715879e149c286dc8aae7",
              "status": "affected",
              "version": "4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7",
              "versionType": "git"
            },
            {
              "lessThan": "a491be376abd1c80a314cdd658632c85cd660b73",
              "status": "affected",
              "version": "4dc0d12474f9d4833c3dd96b73d61e406d3f5dc7",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.17"
            },
            {
              "lessThan": "6.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.52",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.52",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/tegra241-cmdqv: Synchronize the error ISR against VINTF (de)init\n\nA user VINTF is torn down by tegra241_cmdqv_deinit_vintf(), which runs from\nthe destroy callback and from the init-failure unwind in the alloc handler.\nIt clears the cmdqv-\u003evintfs[] slot and lets the iommufd core free it, but\nnothing serializes that against the error interrupt: tegra241_cmdqv_isr()\nreads cmdqv-\u003evintfs[idx] and dereferences the vintf. A concurrent error can\nmake the ISR read a slot mid-clear (a NULL deref) or use a vintf which is\nabout to be freed (a use-after-free).\n\ndeinit_vintf() also returns idx to the IDA before clearing the slot, so a\nconcurrent create that reuses idx can publish its new vintf into the slot,\nonly for this teardown to erase it again with the stale NULL store.\n\nOn the other end, tegra241_cmdqv_init_vintf() publishes a new vintf with a\nplain store to the cmdqv-\u003evintfs[] slot, and the ISR dereferences fields of\na published vintf such as vintf-\u003ebase. A plain store gives no ordering on a\nweakly-ordered CPU, and a stale VINTF_ERR_MAP bit on a reused idx can make\nthe ISR pick a vintf the moment it is published, before its fields are set\nor tegra241_vintf_hw_init() runs.\n\nThe cmdqv-\u003evintfs[0] slot stays NULL until tegra241_cmdqv_init_structures()\nfirst creates VINTF0, so the slot 0 read needs the same NULL check.\n\nPublish every slot with an smp_store_release(), and read each slot in the\nISR with an smp_load_acquire() under a NULL check, so the ISR always sees\na fully built vintf or NULL. Also make deinit_vintf() clear the slot, and\nsynchronize_irq() prior to returning idx to the IDA, so no vintf is freed\nunder a running handler and no reused idx is clobbered."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - tegra241_cmdqv_isr() use-after-frees a user VINTF torn down by tegra241_cmdqv_deinit_vintf() from IOMMU_DESTROY (iommufd_viommu_destroy \u2192 tegra241_cmdqv_destroy_vintf_user) or the unwind of IOMMU_VIOMMU_ALLOC; the malformed stimulus is those /dev/iommu ioctls plus mmap\u0027d VINTF page0 doorbells, not a wire protocol.\nAC:L - The attacker runs both sides: one thread IOMMU_DESTROYs the TEGRA241_CMDQV viommu (or fails tegra241_cmdqv_init_vintf_user after the slot is published) while another enables the mmap\u0027d VCMDQ and rings PROD with an illegal opcode so hardware sets VINTF_ERR_MAP and invokes tegra241_cmdqv_isr() on the slot being cleared.\nPR:L - iommufd_fops_open(), IOMMU_VIOMMU_ALLOC and IOMMU_DESTROY have no capable() check (/dev/iommu 0660). A kvm-group QEMU tenant with a Grace VFIO device binds via VFIO_DEVICE_BIND_IOMMUFD, allocates the vIOMMU/VCMDQ, and races destroy against the ISR without init-namespace root.\nUI:N - The attacker performs the whole sequence on their own fds: open /dev/iommu, VFIO bind, IOMMU_VIOMMU_ALLOC/IOMMU_HW_QUEUE_ALLOC, mmap VINTF page0, enqueue the illegal command, and IOMMU_DESTROY on a second thread; no victim mount or click is required.\nS:U - The ISR use-after-frees the host tegra241_vintf embedded in iommufd_viommu after tegra241_cmdqv_destroy_vintf_user() returns and iommufd kfree\u0027s the object; that is host userspace-to-kernel memory corruption in one OS authority, not a SID/DMA translation bypass or KVM intercept escape.\nC:H - After deinit_vintf() and iommufd free the viommu, tegra241_vintf_user_handle_error() still calls iommufd_viommu_report_event() on the freed object (veventqs_rwsem and veventq list), so reclaiming that heap object yields an arbitrary kernel-read primitive.\nI:H - The same freed iommufd_viommu is then locked and spliced in iommufd_vevent_handler(); spraying the object replaces those list/lock pointers and yields an arbitrary kernel write and control-flow hijack, which UAF guidance scores High.\nA:H - Pre-fix tegra241_cmdqv_isr() calls tegra241_vintf_user_handle_error(cmdqv-\u003evintfs[idx]) with no NULL check, so a mid-clear slot NULL-dereferences and oopses; the concurrent UAF of vintf-\u003ebase or veventqs_rwsem likewise panics the host."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:03:32.827Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/bcb82407633c3008362ad927699d985ee4981557"
        },
        {
          "url": "https://git.kernel.org/stable/c/f3ef4abc271a1d3d7b6715879e149c286dc8aae7"
        },
        {
          "url": "https://git.kernel.org/stable/c/a491be376abd1c80a314cdd658632c85cd660b73"
        }
      ],
      "title": "iommu/tegra241-cmdqv: Synchronize the error ISR against VINTF (de)init",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90429",
    "datePublished": "2026-09-17T16:09:50.442Z",
    "dateReserved": "2026-09-11T19:38:34.814Z",
    "dateUpdated": "2026-10-19T09:03:32.827Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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