{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89489", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.713Z", "datePublished": "2026-09-11T19:43:42.164Z", "dateUpdated": "2026-10-19T08:47:40.968Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:47:40.968Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nopenrisc: fix arbitrary kernel memory access via or1k_atomic syscall\n\nsys_or1k_atomic() (syscall 244 in the \"or1k\" ABI) takes two user\npointers, v1 and v2, and swaps the words they point to in hand-written\nassembly.\n\n l.lwz r29,0(r4)\n l.lwz r27,0(r5)\n l.sw 0(r4),r27\n l.sw 0(r5),r29\n\nThe pointers are not checked with access_ok(). The four memory\naccesses also have no exception table entries.\n\nA caller passes a kernel address as either pointer, and the syscall\nreads from and writes to it directly.\n\nThis gives an unprivileged process a kernel read/write primitive. It\noverwrites kernel data such as the sys_call_table, gaining code\nexecution in kernel context.\n\nCheck both pointers before entering the critical section. Add fixups\nfor the four memory accesses so faults on valid but unmapped user\naddresses return -EFAULT.\n\n[shorne@gmail.com: fix comment style]" } ], "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 - sys_or1k_atomic (syscall 244) is reached only via a local OpenRISC syscall into _sys_call_handler and sys_call_table; there is no network, adjacent-wireless, or physical-device path to the unchecked loads/stores in arch/openrisc/kernel/entry.S.\nAC:L - The attacker fully controls both pointer arguments and the swap is deterministic with no race or KASLR (OpenRISC has none); a published unprivileged PoC on qemu-system-or1k overwrote sys_call_table[174] and obtained uid=0 on every run.\nPR:L - Any unprivileged local process can invoke syscall 244; the handler performs no capable()/ns_capable() check, authentication, or init-namespace root gate before dereferencing the caller-supplied pointers.\nUI:N - The attacking process issues or1k_atomic itself with crafted kernel addresses; no other user must mount a filesystem, open a device, or otherwise interact.\nS:U - This is a standard host-kernel privilege escalation (arbitrary kernel R/W and commit_creds via a hijacked syscall); it does not cross a VM guest/host, IOMMU, or other security-authority boundary.\nC:H - The syscall atomically swaps two 32-bit words at attacker-chosen addresses with no access_ok(), so pairing a kernel pointer with a userspace buffer yields an arbitrary kernel-memory read primitive of any mapped word.\nI:H - The same swap is an arbitrary kernel write; the fix commit documents overwriting sys_call_table to run commit_creds(init_cred) and gain root, i.e. control-flow hijacking and full integrity compromise.\nA:H - Writes to unmapped or critical kernel addresses oops or panic because the original accesses had no exception-table fixups, and corrupting kernel text, data, or the syscall table can hang or crash the machine even without a full root exploit." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/openrisc/kernel/entry.S" ], "versions": [ { "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a", "lessThan": "bf310718c6fa6adeee06d207a55489546d860e2c", "status": "affected", "versionType": "git" }, { "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a", "lessThan": "497cba0b02e5555d99fe9ee1dc478af743ab7f7a", "status": "affected", "versionType": "git" }, { "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a", "lessThan": "1f2e92e499d863f81df1732af59b4a3559969193", "status": "affected", "versionType": "git" }, { "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a", "lessThan": "574ae2ac2b314aa33498cd2c28add106cbe644f2", "status": "affected", "versionType": "git" }, { "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a", "lessThan": "a520e8cac54fb403f3800125b606f55fcad42cb9", "status": "affected", "versionType": "git" }, { "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a", "lessThan": "d64a75369cd0f2ee79afcc9d9ca34a3890989379", "status": "affected", "versionType": "git" }, { "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a", "lessThan": "b53435c079c78f89f70a62dd5a322cca4e292b34", "status": "affected", "versionType": "git" }, { "version": "9d02a4283e9ce4e9ca11ff00615bdacdb0515a1a", "lessThan": "78004e9a87f240df03e2f73120d291763c32e0a7", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/openrisc/kernel/entry.S" ], "versions": [ { "version": "3.1", "status": "affected" }, { "version": "0", "lessThan": "3.1", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "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": "3.1", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.1", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/bf310718c6fa6adeee06d207a55489546d860e2c" }, { "url": "https://git.kernel.org/stable/c/497cba0b02e5555d99fe9ee1dc478af743ab7f7a" }, { "url": "https://git.kernel.org/stable/c/1f2e92e499d863f81df1732af59b4a3559969193" }, { "url": "https://git.kernel.org/stable/c/574ae2ac2b314aa33498cd2c28add106cbe644f2" }, { "url": "https://git.kernel.org/stable/c/a520e8cac54fb403f3800125b606f55fcad42cb9" }, { "url": "https://git.kernel.org/stable/c/d64a75369cd0f2ee79afcc9d9ca34a3890989379" }, { "url": "https://git.kernel.org/stable/c/b53435c079c78f89f70a62dd5a322cca4e292b34" }, { "url": "https://git.kernel.org/stable/c/78004e9a87f240df03e2f73120d291763c32e0a7" } ], "title": "openrisc: fix arbitrary kernel memory access via or1k_atomic syscall", "x_generator": { "engine": "bippy-1.2.0" } } } }