{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-50114", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-10-21T19:36:19.947Z", "datePublished": "2024-11-05T17:10:45.984Z", "dateUpdated": "2026-08-05T11:41:44.557Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:41:44.557Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Unregister redistributor for failed vCPU creation\n\nAlex reports that syzkaller has managed to trigger a use-after-free when\ntearing down a VM:\n\n BUG: KASAN: slab-use-after-free in kvm_put_kvm+0x300/0xe68 virt/kvm/kvm_main.c:5769\n Read of size 8 at addr ffffff801c6890d0 by task syz.3.2219/10758\n\n CPU: 3 UID: 0 PID: 10758 Comm: syz.3.2219 Not tainted 6.11.0-rc6-dirty #64\n Hardware name: linux,dummy-virt (DT)\n Call trace:\n dump_backtrace+0x17c/0x1a8 arch/arm64/kernel/stacktrace.c:317\n show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324\n __dump_stack lib/dump_stack.c:93 [inline]\n dump_stack_lvl+0x94/0xc0 lib/dump_stack.c:119\n print_report+0x144/0x7a4 mm/kasan/report.c:377\n kasan_report+0xcc/0x128 mm/kasan/report.c:601\n __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381\n kvm_put_kvm+0x300/0xe68 virt/kvm/kvm_main.c:5769\n kvm_vm_release+0x4c/0x60 virt/kvm/kvm_main.c:1409\n __fput+0x198/0x71c fs/file_table.c:422\n ____fput+0x20/0x30 fs/file_table.c:450\n task_work_run+0x1cc/0x23c kernel/task_work.c:228\n do_notify_resume+0x144/0x1a0 include/linux/resume_user_mode.h:50\n el0_svc+0x64/0x68 arch/arm64/kernel/entry-common.c:169\n el0t_64_sync_handler+0x90/0xfc arch/arm64/kernel/entry-common.c:730\n el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598\n\nUpon closer inspection, it appears that we do not properly tear down the\nMMIO registration for a vCPU that fails creation late in the game, e.g.\na vCPU w/ the same ID already exists in the VM.\n\nIt is important to consider the context of commit that introduced this bug\nby moving the unregistration out of __kvm_vgic_vcpu_destroy(). That\nchange correctly sought to avoid an srcu v. config_lock inversion by\nbreaking up the vCPU teardown into two parts, one guarded by the\nconfig_lock.\n\nFix the use-after-free while avoiding lock inversion by adding a\nspecial-cased unregistration to __kvm_vgic_vcpu_destroy(). This is safe\nbecause failed vCPUs are torn down outside of the config_lock." } ], "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 bug is reached purely through local ioctls on /dev/kvm (KVM_CREATE_DEVICE, KVM_DEV_ARM_VGIC_GRP_ADDR, KVM_CREATE_VCPU); no network or adjacent-network exposure exists.\nAC:L - Triggering is deterministic and requires no race — issuing KVM_CREATE_VCPU twice with the same vCPU ID (or forcing create_vcpu_fd() to fail via RLIMIT_NOFILE) reliably leaks the registered redistributor iodev, and GICv3 is present on essentially all modern arm64 KVM hosts.\nPR:L - Only access to /dev/kvm is needed, which is mode 0666 under the default systemd udev rule and granted to the kvm group on virtualization hosts and to VM-capable apps on Android AVF; no CAP_SYS_ADMIN or root is required.\nUI:N - The attacker performs every step itself via its own VM file descriptors; no victim action or interaction is involved.\nS:U - The attacker is host userspace escalating within the host kernel — this is not a guest-to-host escape, since the guest cannot cause the duplicate vCPU creation, so the vulnerable and impacted components share one security authority.\nC:H - The stale IODEV_REDIST device lets guest MMIO reads dispatch through freed memory (iodev->regions, nr_regions, redist_vcpu), returning contents of the reallocated kvm_vcpu slab object to the attacker-controlled guest — an arbitrary kernel-memory disclosure primitive.\nI:H - dispatch_mmio_write() calls region->write(iodev->redist_vcpu, ...) using a function-pointer table and vCPU pointer read out of freed memory, giving a controlled write into the reallocated object and a realistic control-flow hijack path to kernel code execution.\nA:H - The use-after-free reliably oopses the host kernel at VM teardown (kvm_io_bus_destroy dereferencing the freed device), as shown by the reported KASAN slab-use-after-free splat." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/arm64/kvm/vgic/vgic-init.c" ], "versions": [ { "version": "f616506754d34bcfdbfbc7508b562e5c98461e9a", "lessThan": "6bcc2890b883ba1d16b8942937750565f6e9db0d", "status": "affected", "versionType": "git" }, { "version": "f616506754d34bcfdbfbc7508b562e5c98461e9a", "lessThan": "ae8f8b37610269009326f4318df161206c59843e", "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/vgic/vgic-init.c" ], "versions": [ { "version": "6.11", "status": "affected" }, { "version": "0", "lessThan": "6.11", "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": "6.11", "versionEndExcluding": "6.11.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "6.12" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/6bcc2890b883ba1d16b8942937750565f6e9db0d" }, { "url": "https://git.kernel.org/stable/c/ae8f8b37610269009326f4318df161206c59843e" } ], "title": "KVM: arm64: Unregister redistributor for failed vCPU creation", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2024-50114", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2024-12-11T14:28:29.483370Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-12-11T14:58:34.119Z" } } ] } }