{"cve":"CVE-2021-47341","nvd":{"published":"2024-05-21T15:15:20.850","modified":"2026-08-04T10:16:58.480","status":"Modified","description":"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---","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/069d44a24c0ff8f85adf49233aae7a8ca16f5c7e","https://git.kernel.org/stable/c/23fa2e46a5556f787ce2ea1a315d3ab93cced204","https://git.kernel.org/stable/c/679837dc0abaa2c6e2a7bcd86483e05eee1d5066","https://git.kernel.org/stable/c/8d7c539316d652d217e5e82b89ee204c812a7061","https://git.kernel.org/stable/c/f2ff9d03432fcb160e9f7d4be26174d89de2779a"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47341","score":0.00255,"percentile":0.17092,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}