{"api_version":"1","generated_at":"2026-08-22T08:43:10+00:00","cve":"CVE-2026-74306","urls":{"html":"https://cve.report/CVE-2026-74306","api":"https://cve.report/api/cve/CVE-2026-74306.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-74306","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-74306"},"summary":{"title":"vfio/qat: fix f_pos race in qat_vf_resume_write()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvfio/qat: fix f_pos race in qat_vf_resume_write()\n\nqat_vf_resume_write() checks filp->f_pos before taking migf->lock, but\ncopies into the migration-state buffer after taking the lock and\nre-reading the shared file position.\n\nTwo concurrent writers could therefore pass the bounds check with the\nold offset, then have the second writer copy after the first advanced\nf_pos, writing past the end of the migration-state buffer.\n\nTake migf->lock before doing the boundary checks.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 06:22:30","updated_at":"2026-08-17 06:19:24"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"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"}}],"references":[{"url":"https://git.kernel.org/stable/c/b6fd7a40a66485c8aa8156d8fcf50b95cb8ba281","name":"https://git.kernel.org/stable/c/b6fd7a40a66485c8aa8156d8fcf50b95cb8ba281","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/4ec5e932e636896e97e4c6a8205b0ac76d52421a","name":"https://git.kernel.org/stable/c/4ec5e932e636896e97e4c6a8205b0ac76d52421a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6465af0004dc1b067129a26ef44f19cdf13bbce6","name":"https://git.kernel.org/stable/c/6465af0004dc1b067129a26ef44f19cdf13bbce6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d416dcefdbac90d96b22485fd93f28229ad9984b","name":"https://git.kernel.org/stable/c/d416dcefdbac90d96b22485fd93f28229ad9984b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74306","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74306","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bb208810b1abf1c84870cfbe1cc9cf1a1d35c607 6465af0004dc1b067129a26ef44f19cdf13bbce6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bb208810b1abf1c84870cfbe1cc9cf1a1d35c607 d416dcefdbac90d96b22485fd93f28229ad9984b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bb208810b1abf1c84870cfbe1cc9cf1a1d35c607 b6fd7a40a66485c8aa8156d8fcf50b95cb8ba281 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bb208810b1abf1c84870cfbe1cc9cf1a1d35c607 4ec5e932e636896e97e4c6a8205b0ac76d52421a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.10","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.10 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.97 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.40 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"74306","cve":"CVE-2026-74306","epss":"0.001280000","percentile":"0.029160000","score_date":"2026-08-17","updated_at":"2026-08-18 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the Linux kernel, the following vulnerability has been resolved:\n\nvfio/qat: fix f_pos race in qat_vf_resume_write()\n\nqat_vf_resume_write() checks filp->f_pos before taking migf->lock, but\ncopies into the migration-state buffer after taking the lock and\nre-reading the shared file position.\n\nTwo concurrent writers could therefore pass the bounds check with the\nold offset, then have the second writer copy after the first advanced\nf_pos, writing past the end of the migration-state buffer.\n\nTake migf->lock before doing the boundary checks."}],"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 - Exploitation requires local write() syscalls on a VFIO live-migration resume fd returned by VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE ioctl on an opened QAT VFIO PCI device; there is no network, adjacent-wireless, or physical-device attack path to this code.\nAC:L - An attacker with the migration fd controls both racing writers (e.g., concurrent threads or dup'd fds sharing f_pos) and can repeatedly trigger the TOCTOU window near the buffer end until the overflow succeeds; no uncontrollable victim timing or memory layout is required.\nPR:L - Exploitation requires only local access to an assigned Intel QAT VFIO device migration fd (typical QEMU/cloud/HPC VFIO clients), not real root in the init namespace; capabilities like CAP_NET_ADMIN via user namespaces do not grant this path.\nUI:N - No victim interaction is required; the attacker drives VFIO migration state transitions and concurrent writes to the resume fd programmatically without any separate user or administrator action during exploitation.\nS:U - The flaw corrupts host kernel heap memory from a VFIO client context and does not by itself cross an IOMMU, VM-guest, or other distinct security authority boundary; impact remains host kernel compromise/DoS within the same authority.\nC:H - The race yields an attacker-controlled heap out-of-bounds write past the 4096-byte migration-state kmalloc buffer, which can corrupt adjacent kernel objects and be leveraged for arbitrary kernel memory disclosure, not merely a bounded leak.\nI:H - copy_from_user() writes attacker-controlled data beyond mig_dev->state, enabling heap corruption and potential arbitrary kernel write or code-execution primitives through grooming of adjacent kmalloc objects.\nA:H - Heap corruption from the out-of-bounds write can immediately panic or oops the kernel or destabilize the system even when full exploitation is not attempted, satisfying high availability impact for kernel memory corruption."}]}],"providerMetadata":{"dateUpdated":"2026-08-17T05:45:40.501Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/6465af0004dc1b067129a26ef44f19cdf13bbce6"},{"url":"https://git.kernel.org/stable/c/d416dcefdbac90d96b22485fd93f28229ad9984b"},{"url":"https://git.kernel.org/stable/c/b6fd7a40a66485c8aa8156d8fcf50b95cb8ba281"},{"url":"https://git.kernel.org/stable/c/4ec5e932e636896e97e4c6a8205b0ac76d52421a"}],"title":"vfio/qat: fix f_pos race in qat_vf_resume_write()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-74306","datePublished":"2026-08-15T05:58:07.313Z","dateReserved":"2026-08-15T05:44:03.883Z","dateUpdated":"2026-08-17T05:45:40.501Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 06:22:30","lastModifiedDate":"2026-08-17 06:19:24","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"74306","Ordinal":"1","Title":"vfio/qat: fix f_pos race in qat_vf_resume_write()","CVE":"CVE-2026-74306","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"74306","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nvfio/qat: fix f_pos race in qat_vf_resume_write()\n\nqat_vf_resume_write() checks filp->f_pos before taking migf->lock, but\ncopies into the migration-state buffer after taking the lock and\nre-reading the shared file position.\n\nTwo concurrent writers could therefore pass the bounds check with the\nold offset, then have the second writer copy after the first advanced\nf_pos, writing past the end of the migration-state buffer.\n\nTake migf->lock before doing the boundary checks.","Type":"Description","Title":"vfio/qat: fix f_pos race in qat_vf_resume_write()"}]}}}