{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-47341", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-21T14:28:16.979Z", "datePublished": "2024-05-21T14:35:49.001Z", "dateUpdated": "2026-08-05T08:47:18.943Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:47:18.943Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: mmio: Fix use-after-free Read in kvm_vm_ioctl_unregister_coalesced_mmio\n\nBUG: KASAN: use-after-free in kvm_vm_ioctl_unregister_coalesced_mmio+0x7c/0x1ec arch/arm64/kvm/../../../virt/kvm/coalesced_mmio.c:183\nRead of size 8 at addr ffff0000c03a2500 by task syz-executor083/4269\n\nCPU: 5 PID: 4269 Comm: syz-executor083 Not tainted 5.10.0 #7\nHardware name: linux,dummy-virt (DT)\nCall trace:\n dump_backtrace+0x0/0x2d0 arch/arm64/kernel/stacktrace.c:132\n show_stack+0x28/0x34 arch/arm64/kernel/stacktrace.c:196\n __dump_stack lib/dump_stack.c:77 [inline]\n dump_stack+0x110/0x164 lib/dump_stack.c:118\n print_address_description+0x78/0x5c8 mm/kasan/report.c:385\n __kasan_report mm/kasan/report.c:545 [inline]\n kasan_report+0x148/0x1e4 mm/kasan/report.c:562\n check_memory_region_inline mm/kasan/generic.c:183 [inline]\n __asan_load8+0xb4/0xbc mm/kasan/generic.c:252\n kvm_vm_ioctl_unregister_coalesced_mmio+0x7c/0x1ec arch/arm64/kvm/../../../virt/kvm/coalesced_mmio.c:183\n kvm_vm_ioctl+0xe30/0x14c4 arch/arm64/kvm/../../../virt/kvm/kvm_main.c:3755\n vfs_ioctl fs/ioctl.c:48 [inline]\n __do_sys_ioctl fs/ioctl.c:753 [inline]\n __se_sys_ioctl fs/ioctl.c:739 [inline]\n __arm64_sys_ioctl+0xf88/0x131c fs/ioctl.c:739\n __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline]\n invoke_syscall arch/arm64/kernel/syscall.c:48 [inline]\n el0_svc_common arch/arm64/kernel/syscall.c:158 [inline]\n do_el0_svc+0x120/0x290 arch/arm64/kernel/syscall.c:220\n el0_svc+0x1c/0x28 arch/arm64/kernel/entry-common.c:367\n el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383\n el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670\n\nAllocated by task 4269:\n stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121\n kasan_save_stack mm/kasan/common.c:48 [inline]\n kasan_set_track mm/kasan/common.c:56 [inline]\n __kasan_kmalloc+0xdc/0x120 mm/kasan/common.c:461\n kasan_kmalloc+0xc/0x14 mm/kasan/common.c:475\n kmem_cache_alloc_trace include/linux/slab.h:450 [inline]\n kmalloc include/linux/slab.h:552 [inline]\n kzalloc include/linux/slab.h:664 [inline]\n kvm_vm_ioctl_register_coalesced_mmio+0x78/0x1cc arch/arm64/kvm/../../../virt/kvm/coalesced_mmio.c:146\n kvm_vm_ioctl+0x7e8/0x14c4 arch/arm64/kvm/../../../virt/kvm/kvm_main.c:3746\n vfs_ioctl fs/ioctl.c:48 [inline]\n __do_sys_ioctl fs/ioctl.c:753 [inline]\n __se_sys_ioctl fs/ioctl.c:739 [inline]\n __arm64_sys_ioctl+0xf88/0x131c fs/ioctl.c:739\n __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline]\n invoke_syscall arch/arm64/kernel/syscall.c:48 [inline]\n el0_svc_common arch/arm64/kernel/syscall.c:158 [inline]\n do_el0_svc+0x120/0x290 arch/arm64/kernel/syscall.c:220\n el0_svc+0x1c/0x28 arch/arm64/kernel/entry-common.c:367\n el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383\n el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670\n\nFreed by task 4269:\n stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121\n kasan_save_stack mm/kasan/common.c:48 [inline]\n kasan_set_track+0x38/0x6c mm/kasan/common.c:56\n kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:355\n __kasan_slab_free+0x124/0x150 mm/kasan/common.c:422\n kasan_slab_free+0x10/0x1c mm/kasan/common.c:431\n slab_free_hook mm/slub.c:1544 [inline]\n slab_free_freelist_hook mm/slub.c:1577 [inline]\n slab_free mm/slub.c:3142 [inline]\n kfree+0x104/0x38c mm/slub.c:4124\n coalesced_mmio_destructor+0x94/0xa4 arch/arm64/kvm/../../../virt/kvm/coalesced_mmio.c:102\n kvm_iodevice_destructor include/kvm/iodev.h:61 [inline]\n kvm_io_bus_unregister_dev+0x248/0x280 arch/arm64/kvm/../../../virt/kvm/kvm_main.c:4374\n kvm_vm_ioctl_unregister_coalesced_mmio+0x158/0x1ec arch/arm64/kvm/../../../virt/kvm/coalesced_mmio.c:186\n kvm_vm_ioctl+0xe30/0x14c4 arch/arm64/kvm/../../../virt/kvm/kvm_main.c:3755\n vfs_ioctl fs/ioctl.c:48 [inline]\n __do_sys_ioctl fs/ioctl.c:753 [inline]\n __se_sys_ioctl fs/ioctl.c:739 [inline]\n __arm64_sys_ioctl+0xf88/0x131c fs/ioctl.c:739\n __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline]\n invoke_syscall arch/arm64/kernel/sys\n---truncated---" } ], "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 - Reachable only via local host ioctls on /dev/kvm (KVM_CREATE_VM then KVM_REGISTER/UNREGISTER_COALESCED_MMIO through kvm_vm_ioctl); not via network packets or unaided guest MMIO.\nAC:L - The attacker fully controls zone registration/unregistration and can reliably force the GFP_KERNEL_ACCOUNT kmalloc failure in kvm_io_bus_unregister_dev (e.g. memcg/memory pressure) that triggers the UAF path.\nPR:L - The ioctl path has no capable() check; access needs only /dev/kvm permissions (kvm group or seat uaccess), which is unprivileged device access rather than init-namespace root.\nUI:N - The attacker triggers the bug directly with their own KVM ioctls; no separate victim action is required.\nS:U - This is host userspace (VMM) corrupting host kernel state via the KVM ioctl interface, not a guest-to-host escape across a VM security boundary.\nC:H - KASAN-confirmed use-after-free of kvm_coalesced_mmio_dev heap objects; freed objects can be reallocated/sprayed to obtain arbitrary kernel memory disclosure.\nI:H - UAF/double-free of IO-bus device objects enables heap corruption and write primitives that can hijack kernel control flow.\nA:H - Dereferencing freed coalesced-MMIO list/device objects causes kernel oops/panic, and UAF paths remain crashable even without full exploitation." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "virt/kvm/coalesced_mmio.c" ], "versions": [ { "version": "7d1bc32d6477ff96a32695ea4be8144e4513ab2d", "lessThan": "f2ff9d03432fcb160e9f7d4be26174d89de2779a", "status": "affected", "versionType": "git" }, { "version": "2a20592baff59c5351c5200ec667e1a2aa22af85", "lessThan": "679837dc0abaa2c6e2a7bcd86483e05eee1d5066", "status": "affected", "versionType": "git" }, { "version": "50cbad42bfea8c052b7ca590bd4126cdc898713c", "lessThan": "8d7c539316d652d217e5e82b89ee204c812a7061", "status": "affected", "versionType": "git" }, { "version": "5d3c4c79384af06e3c8e25b7770b6247496b4417", "lessThan": "069d44a24c0ff8f85adf49233aae7a8ca16f5c7e", "status": "affected", "versionType": "git" }, { "version": "5d3c4c79384af06e3c8e25b7770b6247496b4417", "lessThan": "23fa2e46a5556f787ce2ea1a315d3ab93cced204", "status": "affected", "versionType": "git" }, { "version": "168e82f640ed1891a700bdb43e37da354b2ab63c", "status": "affected", "versionType": "git" }, { "version": "5.4.119", "lessThan": "5.4.134", "status": "affected", "versionType": "semver" }, { "version": "5.10.37", "lessThan": "5.10.52", "status": "affected", "versionType": "semver" }, { "version": "5.12.4", "lessThan": "5.12.19", "status": "affected", "versionType": "semver" }, { "version": "5.11.21", "lessThan": "5.12", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "virt/kvm/coalesced_mmio.c" ], "versions": [ { "version": "5.13", "status": "affected" }, { "version": "0", "lessThan": "5.13", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.134", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.52", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.12.19", "lessThanOrEqual": "5.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.13.4", "lessThanOrEqual": "5.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.14", "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": "5.4.119", "versionEndExcluding": "5.4.134" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.37", "versionEndExcluding": "5.10.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12.4", "versionEndExcluding": "5.12.19" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "5.13.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "5.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11.21" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f2ff9d03432fcb160e9f7d4be26174d89de2779a" }, { "url": "https://git.kernel.org/stable/c/679837dc0abaa2c6e2a7bcd86483e05eee1d5066" }, { "url": "https://git.kernel.org/stable/c/8d7c539316d652d217e5e82b89ee204c812a7061" }, { "url": "https://git.kernel.org/stable/c/069d44a24c0ff8f85adf49233aae7a8ca16f5c7e" }, { "url": "https://git.kernel.org/stable/c/23fa2e46a5556f787ce2ea1a315d3ab93cced204" } ], "title": "KVM: mmio: Fix use-after-free Read in kvm_vm_ioctl_unregister_coalesced_mmio", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:32:08.601Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/f2ff9d03432fcb160e9f7d4be26174d89de2779a", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/679837dc0abaa2c6e2a7bcd86483e05eee1d5066", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/8d7c539316d652d217e5e82b89ee204c812a7061", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/069d44a24c0ff8f85adf49233aae7a8ca16f5c7e", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/23fa2e46a5556f787ce2ea1a315d3ab93cced204", "tags": [ "x_transferred" ] } ] }, { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2021-47341", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-09-10T15:38:50.302115Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-09-11T17:33:49.116Z" } } ] } }