{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-50139", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-10-21T19:36:19.956Z", "datePublished": "2024-11-07T09:31:15.925Z", "dateUpdated": "2026-08-05T11:41:58.518Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:41:58.518Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Fix shift-out-of-bounds bug\n\nFix a shift-out-of-bounds bug reported by UBSAN when running\nVM with MTE enabled host kernel.\n\nUBSAN: shift-out-of-bounds in arch/arm64/kvm/sys_regs.c:1988:14\nshift exponent 33 is too large for 32-bit type 'int'\nCPU: 26 UID: 0 PID: 7629 Comm: qemu-kvm Not tainted 6.12.0-rc2 #34\nHardware name: IEI NF5280R7/Mitchell MB, BIOS 00.00. 2024-10-12 09:28:54 10/14/2024\nCall trace:\n dump_backtrace+0xa0/0x128\n show_stack+0x20/0x38\n dump_stack_lvl+0x74/0x90\n dump_stack+0x18/0x28\n __ubsan_handle_shift_out_of_bounds+0xf8/0x1e0\n reset_clidr+0x10c/0x1c8\n kvm_reset_sys_regs+0x50/0x1c8\n kvm_reset_vcpu+0xec/0x2b0\n __kvm_vcpu_set_target+0x84/0x158\n kvm_vcpu_set_target+0x138/0x168\n kvm_arch_vcpu_ioctl_vcpu_init+0x40/0x2b0\n kvm_arch_vcpu_ioctl+0x28c/0x4b8\n kvm_vcpu_ioctl+0x4bc/0x7a8\n __arm64_sys_ioctl+0xb4/0x100\n invoke_syscall+0x70/0x100\n el0_svc_common.constprop.0+0x48/0xf0\n do_el0_svc+0x24/0x38\n el0_svc+0x3c/0x158\n el0t_64_sync_handler+0x120/0x130\n el0t_64_sync+0x194/0x198" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H", "baseScore": 7.9, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable code is reached through `ioctl(KVM_ARM_VCPU_INIT)` on a local `/dev/kvm` vCPU file descriptor, or from a local VM guest via a PSCI CPU_ON SMC that queues `KVM_REQ_VCPU_RESET`. No network protocol is involved on either path.\nAC:L - The out-of-bounds shift is fully deterministic — no race, no memory-layout dependency, no timing window; the attacker simply enables `KVM_CAP_ARM_MTE` and initializes a vCPU, and the shift executes unconditionally under `kvm_has_mte()`.\nPR:L - No capability check exists anywhere along the path — only an open `/dev/kvm` descriptor, which unprivileged members of the `kvm` group hold on standard distributions, or control of a guest for the PSCI path. Not PR:N, since some local foothold is required.\nUI:N - Triggering requires only the attacker's own ioctl sequence or an SMC issued from inside a VM they already control; no action by any other user or administrator is needed.\nS:C - The defect crosses the host/guest security boundary in both directions — the host hypervisor writes architecturally-invalid CPU state into the guest, and via the guest-reachable PSCI `CPU_ON` path a VM-confined attacker drives a UBSAN violation in host kernel context, which under `CONFIG_UBSAN_TRAP` or `panic_on_warn` takes down the host and every co-resident VM.\nC:L - There is no out-of-bounds read or memory disclosure primitive, but the UBSAN report and the `die()`/oops path dump host kernel addresses and a full backtrace to the kernel log, giving a bounded kernel-pointer leak that undermines KASLR for a locally-triggering attacker.\nI:L - The hypervisor stores a corrupted `CLIDR_EL1` with a reserved `Ctype` encoding and missing MTE `Ttypen` fields into guest-visible CPU state, so protected data across the boundary is modified — but the written value is fixed and not attacker-controlled, and there is no write primitive or control-flow hijack.\nA:H - `ubsan_epilogue()` calls `check_panic_on_warn(\"UBSAN\")`, panicking the host on the widely deployed `panic_on_warn=1` setting, and `CONFIG_UBSAN_TRAP=y` turns the shift into a BRK handled by `die()` in kernel context while `kvm->arch.config_lock` is held — a host kernel crash that destroys all running guests." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/arm64/kvm/sys_regs.c" ], "versions": [ { "version": "7af0c2534f4c57b16e92dfca8c5f40fa90fbb3f3", "lessThan": "04ed2ba07ce73f323052475fbd33d647aca3ff2e", "status": "affected", "versionType": "git" }, { "version": "7af0c2534f4c57b16e92dfca8c5f40fa90fbb3f3", "lessThan": "4b9e11794d910aa55300debbac5f0adcc42c491a", "status": "affected", "versionType": "git" }, { "version": "7af0c2534f4c57b16e92dfca8c5f40fa90fbb3f3", "lessThan": "c6c167afa090ea0451f91814e1318755a8fb8bb9", "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/arm64/kvm/sys_regs.c" ], "versions": [ { "version": "6.3", "status": "affected" }, { "version": "0", "lessThan": "6.3", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.59", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.11.6", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12", "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": "6.3", "versionEndExcluding": "6.6.59" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "6.11.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "6.12" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/04ed2ba07ce73f323052475fbd33d647aca3ff2e" }, { "url": "https://git.kernel.org/stable/c/4b9e11794d910aa55300debbac5f0adcc42c491a" }, { "url": "https://git.kernel.org/stable/c/c6c167afa090ea0451f91814e1318755a8fb8bb9" } ], "title": "KVM: arm64: Fix shift-out-of-bounds bug", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2024-50139", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2025-10-01T20:21:13.947802Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "description": "CWE-noinfo Not enough information" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-10-01T20:27:14.564Z" } } ] } }