{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-90244", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2026-90244" ], "published": "2026-09-17T16:10:40Z", "summary": "iommu/dma: Restore locking around msi_page_list", "details": "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.", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:13", "name": "linux" }, "versions": [ "1:6.18.29-1+rpt1", "1:6.18.33-1+rpt1", "1:6.18.34-1+rpt1", "1:6.18.39-1+rpt1", "1:6.18.50-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.18.29+rpt-rpi-2712", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8-rt", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-2712", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8-rt", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-2712", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8-rt", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-2712", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8-rt", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-2712", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v8", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v8-rt", "binary_version": "1:6.18.50-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.18.29-1+rpt1": { "linux_commit": "66318c5b5cd8145a662303af12ed39ac07eb27cc", "upstream_version": "6.18.29", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" }, "1:6.18.33-1+rpt1": { "linux_commit": "95b85bebbedcaedfa7ca79116ed38b7376fba412", "upstream_version": "6.18.33", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" }, "1:6.18.34-1+rpt1": { "linux_commit": "c8c7494100e99ee05b11aaa4f0588a223a63d1af", "upstream_version": "6.18.34", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" }, "1:6.18.39-1+rpt1": { "linux_commit": "60ea684a8ace97bb0db1a16e20753bdd6ab371ff", "upstream_version": "6.18.39", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" }, "1:6.18.50-1+rpt1": { "linux_commit": "cff533aec2fa601846766b32ff57204e0a61bed7", "upstream_version": "6.18.50", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-90244" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/e3c53e9173a47d5ce1fae020f2c6b1fb3c1123c2" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/2af1e99ec14d226d66ceb9f16c663ee2568e6676" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/5a9e89ea34e0e34ac5d7e949042d665533549e40" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-09-18T17:55:42Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.8, "cvss_v3_severity": "High", "scenario": "AV:L - The race is entered only via ioctl(VFIO_DEVICE_SET_IRQS) on a local vfio-pci fd: vfio_pci_core_ioctl \u2192 vfio_pci_ioctl_set_irqs \u2192 vfio_pci_set_msi_trigger \u2192 vfio_msi_enable \u2192 pci_alloc_irq_vectors \u2192 its_irq_domain_alloc \u2192 iommu_dma_prepare_msi \u2192 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." } } }