{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90244","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.795Z","datePublished":"2026-09-17T16:07:47.121Z","dateUpdated":"2026-09-18T17:54:08.500Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-18T17:54:08.500Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/dma: Restore locking around msi_page_list\n\nUnlike a group's default domain, which is always freshly allocated\nand privately owned (iommu_group_alloc_default_domain()), VFIO type1's\nlegacy container merges any newly attached group into an existing\ndomain whenever their iommu_ops and cache-coherency enforcement match.\n\niommu_dma_get_msi_page() only asserts the caller's own group mutex is\nheld (iommu_group_mutex_assert()). On an IOMMU that publishes\nIOMMU_RESV_SW_MSI, e.g. ARM SMMU, a VM with two such devices assigned\nthrough the legacy container can have their guest drivers probe and\nallocate MSIs in parallel; each host-side VFIO_DEVICE_SET_IRQS lands\non a different device fd and group mutex, but both devices' domains\nare the same merged domain, so both can enter\niommu_dma_get_msi_page() concurrently and corrupt msi_page_list.\n\ncommit 288683c92b1a (\"iommu: Make iommu_dma_prepare_msi() into a\ngeneric operation\") dropped the prior msi_prepare_lock on the\nreasoning that \"each iommu_domain is unique to a group,\" which holds\nfor default domains but not this VFIO type1 case. Restore the static\nlock, since it's only guarding a corner case and will likely never\nbe contended.\n\niommufd avoids the equivalent problem by having its own callers\n(iommufd_sw_map_msi()) take a ctx-wide sw_msi_lock before ever\nreaching the shared list. VFIO type1 can't mirror that since it\ndispatches to iommu_dma_sw_msi() which is outside VFIO's jurisdiction."}],"metrics":[{"cvssV3_1":{"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"},"scenarios":[{"lang":"en","value":"AV:L - The race is entered only via ioctl(VFIO_DEVICE_SET_IRQS) on a local vfio-pci fd: vfio_pci_core_ioctl → vfio_pci_ioctl_set_irqs → vfio_pci_set_msi_trigger → vfio_msi_enable → pci_alloc_irq_vectors → its_irq_domain_alloc → iommu_dma_prepare_msi → iommu_dma_get_msi_page. No received packet or protocol message carries the trigger.\nAC:L - The attacker issues concurrent VFIO_DEVICE_SET_IRQS on two device fds whose groups vfio_iommu_type1_attach_group already merged onto one domain; iommu_dma_prepare_msi takes only each device's own group->mutex, so both threads run iommu_dma_get_msi_page() on the shared msi_page_list. The attacker owns both sides of the race.\nPR:L - vfio_pci_ioctl_set_irqs() and vfio_group_fops_open() have no capable() check on the IOMMU-backed path; CAP_SYS_RAWIO gates only VFIO_NO_IOMMU. An unprivileged qemu/kvm-group or DPDK user with two assigned /dev/vfio nodes can attach them to a type1 container and call SET_IRQS.\nUI:N - The attacker attaches its own groups with vfio_iommu_type1_attach_group and fires the concurrent SET_IRQS ioctls on fds it already holds; no other user must mount, open, or otherwise act.\nS:U - The race corrupts the host kernel's msi_page_list of iommu_dma_msi_page objects. iommu_map() still maps only the irqchip doorbell from its->get_msi_base() into the IOMMU_RESV_SW_MSI window vfio_iommu_has_sw_msi() reserved; that does not install extra host-RAM translations or bypass the DMA/VM isolation boundary.\nC:H - Concurrent list_for_each_entry() versus unlocked list_add() on msi_page_list can follow a torn next pointer into a freed iommu_dma_msi_page, a use-after-free read of phys/iova and neighboring slab.\nI:H - Unlocked list_add() of iommu_dma_msi_page nodes overwrites kernel list next/prev, and the unlocked msi_cookie->msi_iova bump in iommu_dma_alloc_iova() can alias IOVAs; a sprayable UAF of that object is an arbitrary-write and control-flow primitive.\nA:H - A corrupted msi_page_list walk or list_add in iommu_dma_get_msi_page() dereferences invalid list pointers and oopses or panics the host kernel even if the UAF is not fully weaponized."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/dma-iommu.c"],"versions":[{"version":"288683c92b1abc32277c83819bea287af614d239","lessThan":"e3c53e9173a47d5ce1fae020f2c6b1fb3c1123c2","status":"affected","versionType":"git"},{"version":"288683c92b1abc32277c83819bea287af614d239","lessThan":"2af1e99ec14d226d66ceb9f16c663ee2568e6676","status":"affected","versionType":"git"},{"version":"288683c92b1abc32277c83819bea287af614d239","lessThan":"5a9e89ea34e0e34ac5d7e949042d665533549e40","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/dma-iommu.c"],"versions":[{"version":"6.15","status":"affected"},{"version":"0","lessThan":"6.15","status":"unaffected","versionType":"semver"},{"version":"6.18.52","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.6","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"6.18.52"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.3-rc1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/e3c53e9173a47d5ce1fae020f2c6b1fb3c1123c2"},{"url":"https://git.kernel.org/stable/c/2af1e99ec14d226d66ceb9f16c663ee2568e6676"},{"url":"https://git.kernel.org/stable/c/5a9e89ea34e0e34ac5d7e949042d665533549e40"}],"title":"iommu/dma: Restore locking around msi_page_list","x_generator":{"engine":"bippy-1.2.0"}}}}