{"id":"CVE-2026-74355","state":"PUBLISHED","title":"iommu/vt-d: Fix RB-tree corruption in probe error path","description":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Fix RB-tree corruption in probe error path\n\nThe info->node RB-tree member is zero-initialized via kzalloc. If\na device does not support ATS, the device_rbtree_insert() call is\nskipped. If a subsequent probe step fails, the error path jumps to\ndevice_rbtree_remove(), which misinterprets the zeroed node as\na tree root and corrupts the device RB-tree.\n\nFix this by explicitly initializing the RB-node as empty using\nRB_CLEAR_NODE() during initialization and guarding the removal with\nRB_EMPTY_NODE().","publishedAt":"2026-08-15T05:58:40.766Z","updatedAt":"2026-10-16T18:55:35.014Z","severity":{"score":8.2,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4f1492efb495bcef34c9ee8a94af81e6cea5abf4","status":"affected","lessThan":"f5102e0fc3c6dc8685549891a96e4589fdb3e211","versionType":"git"},{"version":"4f1492efb495bcef34c9ee8a94af81e6cea5abf4","status":"affected","lessThan":"d16923a45d4d08367650fdc3451c89299ab6ac5a","versionType":"git"},{"version":"4f1492efb495bcef34c9ee8a94af81e6cea5abf4","status":"affected","lessThan":"43bd9e6d5513cb1edbafdeef146a1edc3aaced56","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/intel/iommu.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/intel/iommu.c"]}],"references":["https://git.kernel.org/stable/c/f5102e0fc3c6dc8685549891a96e4589fdb3e211","https://git.kernel.org/stable/c/d16923a45d4d08367650fdc3451c89299ab6ac5a","https://git.kernel.org/stable/c/43bd9e6d5513cb1edbafdeef146a1edc3aaced56"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74355.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74355","state":"PUBLISHED","datePublished":"2026-08-15T05:58:40.766Z","dateUpdated":"2026-10-16T18:55:35.014Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.887Z"},"containers":{"cna":{"title":"iommu/vt-d: Fix RB-tree corruption in probe error path","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Fix RB-tree corruption in probe error path\n\nThe info->node RB-tree member is zero-initialized via kzalloc. If\na device does not support ATS, the device_rbtree_insert() call is\nskipped. If a subsequent probe step fails, the error path jumps to\ndevice_rbtree_remove(), which misinterprets the zeroed node as\na tree root and corrupts the device RB-tree.\n\nFix this by explicitly initializing the RB-node as empty using\nRB_CLEAR_NODE() during initialization and guarding the removal with\nRB_EMPTY_NODE()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4f1492efb495bcef34c9ee8a94af81e6cea5abf4","status":"affected","lessThan":"f5102e0fc3c6dc8685549891a96e4589fdb3e211","versionType":"git"},{"version":"4f1492efb495bcef34c9ee8a94af81e6cea5abf4","status":"affected","lessThan":"d16923a45d4d08367650fdc3451c89299ab6ac5a","versionType":"git"},{"version":"4f1492efb495bcef34c9ee8a94af81e6cea5abf4","status":"affected","lessThan":"43bd9e6d5513cb1edbafdeef146a1edc3aaced56","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/intel/iommu.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/intel/iommu.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f5102e0fc3c6dc8685549891a96e4589fdb3e211"},{"url":"https://git.kernel.org/stable/c/d16923a45d4d08367650fdc3451c89299ab6ac5a"},{"url":"https://git.kernel.org/stable/c/43bd9e6d5513cb1edbafdeef146a1edc3aaced56"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","baseScore":8.2,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is hit in intel_iommu_probe_device() during IOMMU device probing on the PCI bus notifier path (BUS_NOTIFY_ADD_DEVICE), which is only reachable via local kernel actions such as PCI hotplug/rescan, SR-IOV VF creation, or driver bind—not via any network protocol.\nAC:L - A privileged attacker can reliably trigger the fault path by inducing PASID table allocation failure (e.g., memory pressure) while adding or reprobing a non-ATS PCI function on a VT-d scalable-mode host where ATS-capable devices may already populate the IOMMU device RB-tree.\nPR:H - Reaching intel_iommu_probe_device() requires adding or reprobing PCI/IOMMU devices through kernel-local administration (CAP_SYS_ADMIN for sysfs rescan/SR-IOV, or equivalent host control); this cannot be done from an unprivileged user or user namespace alone.\nUI:N - Exploitation does not depend on any victim user action beyond the attacker (or administrator) initiating device probe/hotplug; no interactive user steps are required once the privileged trigger is performed.\nS:C - Corrupting the Intel VT-d device RB-tree breaks RID-to-device tracking used for IOMMU page-request and invalidation handling, which can undermine DMA/IOMMU isolation boundaries (e.g., SR-IOV/assigned-device or host DMA containment), not just the probing process itself.\nC:H - Calling rb_erase() on a zero-initialized RB-node can null the tree root and corrupt kernel RB-tree pointers; such kernel memory corruption is exploitable to obtain arbitrary read primitives or leak sensitive kernel data during subsequent lookups.\nI:H - The erroneous rb_erase() performs out-of-tree pointer writes that corrupt IOMMU device tracking structures, providing a kernel memory corruption primitive that can be developed into arbitrary write or code execution.\nA:H - RB-tree corruption in the IOMMU device map can cause kernel oopses/panics during later device_rbtree_find() operations in interrupt-driven VT-d page-request or invalidation-timeout paths, resulting in complete loss of kernel availability."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:46:16.092Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-74355","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T18:54:21.858928Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T18:55:35.014Z"}}]}}}