{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90383", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.809Z", "datePublished": "2026-09-17T16:09:19.875Z", "dateUpdated": "2026-10-21T12:51:25.790Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:51:25.790Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmisc: sgi-gru: remove interrupt-context page-table walks\n\nThe GRU TLB miss handler walks a process's page tables without holding\npage-table locks or a reference to the mapped page. It also uses a kernel\npage-table accessor on user page tables and supports only PMD-level large\nmappings on x86-64.\n\nRemove the direct walker. Send interrupt faults directly to user polling\nmode so the existing call-OS fallback retries them in process context.\n\nRemove the mmap-lock failure statistic that can no longer be incremented." } ], "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 attacker supplies the faulting VA by writing a virtual-mode GRU vload/vstore/bcopy into the mmap'd GSEG on /dev/gru. gru_fault loads the context; the miss is handled by gru_intr (default GRU_OPT_MISS_FMM_INTR) or ioctl GRU_USER_CALL_OS (gru_handle_user_call_os), both of which called atomic_pte_lookup on that missvaddr.\nAC:L - gru_create_new_context defaults to GRU_OPT_MISS_FMM_INTR, so a mapped-mode GRU instruction reliably hits gru_intr, which mmap_read_trylocks gts->ts_mm and runs atomic_pte_lookup. A 1GB hugetlb VMA is mis-walked with no race because pud_leaf is never checked; a second thread of the same process can also madvise/unmap during the unlocked walk.\nPR:L - gru_fops has no .open method and gru_file_mmap/gru_file_unlocked_ioctl do not call capable(). An unprivileged process that can open miscdevice \"gru\" (/dev/gru) can mmap the GSEG, ioctl GRU_CREATE_CONTEXT, and issue GRU instructions that reach atomic_pte_lookup; only gru_unload_all_contexts requires CAP_SYS_ADMIN.\nUI:N - The attacker alone opens /dev/gru, maps the GSEG, calls GRU_CREATE_CONTEXT, and issues the GRU instruction or GRU_USER_CALL_OS ioctl; no other user needs to act.\nS:U - atomic_pte_lookup feeds a GPA to tfh_write_restart on the host GRU chiplet. A bad PFN lets GRU DMA into host kernel or other-process memory, which is privilege escalation in the same kernel authority, not a guest-to-host or IOMMU-domain crossing.\nC:H - atomic_pte_lookup never tests pud_leaf, so pud_pgtable() on a 1GB hugetlb leaf treats attacker-controlled hugepage bytes as PMD/PTE entries. pte_pfn of that crafted entry is installed by tfh_write_restart, and gru_vload/bcopy then reads that physical page into the attacker-mapped GSEG. The walk also never pins the page, so a stale PFN can be read after reuse.\nI:H - gru_vstore, gru_bcopy, and AMO opcodes write through the GRU TLB entry programmed by tfh_write_restart. A PFN taken from the pud_leaf miswalk of attacker-controlled 1GB hugepage contents, or from an unpinned PTE reused after free, is therefore an arbitrary physical write.\nA:H - pte_offset_kernel() on a pud_leaf 1GB mapping (or on a PMD that is not a table) computes __va of a non-page-table PFN and dereferences it in gru_intr/atomic_pte_lookup, oopsing the kernel. GRU DMA through a stale unpinned PFN can also panic." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/misc/sgi-gru/grufault.c", "drivers/misc/sgi-gru/gruprocfs.c", "drivers/misc/sgi-gru/grutables.h" ], "versions": [ { "version": "142586409c8be7dc071bb94d7cd2d69ccfd99b6b", "lessThan": "5a540ced720b4397306337cab34af1af4b30827c", "status": "affected", "versionType": "git" }, { "version": "142586409c8be7dc071bb94d7cd2d69ccfd99b6b", "lessThan": "877423f595b60f8fe7c18b64a5d283d9e1732a13", "status": "affected", "versionType": "git" }, { "version": "142586409c8be7dc071bb94d7cd2d69ccfd99b6b", "lessThan": "6248eb1833ff0adfdbbadd5f846c2f22e02a01b0", "status": "affected", "versionType": "git" }, { "version": "142586409c8be7dc071bb94d7cd2d69ccfd99b6b", "lessThan": "ef81e4a1628ecfb9cfc442de10883f383faf17a1", "status": "affected", "versionType": "git" }, { "version": "142586409c8be7dc071bb94d7cd2d69ccfd99b6b", "lessThan": "928a8e9f523df845fc496bcb9811013b67aabec5", "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/misc/sgi-gru/grufault.c", "drivers/misc/sgi-gru/gruprocfs.c", "drivers/misc/sgi-gru/grutables.h" ], "versions": [ { "version": "2.6.27", "status": "affected" }, { "version": "0", "lessThan": "2.6.27", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "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", "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": "2.6.27", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/5a540ced720b4397306337cab34af1af4b30827c" }, { "url": "https://git.kernel.org/stable/c/877423f595b60f8fe7c18b64a5d283d9e1732a13" }, { "url": "https://git.kernel.org/stable/c/6248eb1833ff0adfdbbadd5f846c2f22e02a01b0" }, { "url": "https://git.kernel.org/stable/c/ef81e4a1628ecfb9cfc442de10883f383faf17a1" }, { "url": "https://git.kernel.org/stable/c/928a8e9f523df845fc496bcb9811013b67aabec5" } ], "title": "misc: sgi-gru: remove interrupt-context page-table walks", "x_generator": { "engine": "bippy-1.2.0" } } } }