{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47462 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47462 is a medium-severity vulnerability in Linux kernel, published on 22 May 2024. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-47462 and fix it if it is affected.\n\nWhat it is: CVE-2021-47462 is a medium-severity vulnerability in Linux kernel, published on 22 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-47462 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2021-47462/ (Markdown: https://insights.sbomify.com/CVE-2021-47462/index.md)","id":"CVE-2021-47462","markdown":"https://insights.sbomify.com/CVE-2021-47462/index.md","name":"CVE-2021-47462","record":{"aliases":["DEBIAN-CVE-2021-47462","GHSA-5573-w6h2-wwx8","UBUNTU-CVE-2021-47462"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A local attacker can trigger a kernel panic via uninitialized memory access in the mbind system call, causing denial of service.","user_interaction":"not_required","vuln_class":"null_dereference"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-908","name":"Use of Uninitialized Resource"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/mempolicy: do not allow illegal MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind()\n\nsyzbot reported access to unitialized memory in mbind() [1]\n\nIssue came with commit bda420b98505 (\"numa balancing: migrate on fault\namong multiple bound nodes\")\n\nThis commit added a new bit in MPOL_MODE_FLAGS, but only checked valid\ncombination (MPOL_F_NUMA_BALANCING can only be used with MPOL_BIND) in\ndo_set_mempolicy()\n\nThis patch moves the check in sanitize_mpol_flags() so that it is also\nused by mbind()\n\n  [1]\n  BUG: KMSAN: uninit-value in __mpol_equal+0x567/0x590 mm/mempolicy.c:2260\n   __mpol_equal+0x567/0x590 mm/mempolicy.c:2260\n   mpol_equal include/linux/mempolicy.h:105 [inline]\n   vma_merge+0x4a1/0x1e60 mm/mmap.c:1190\n   mbind_range+0xcc8/0x1e80 mm/mempolicy.c:811\n   do_mbind+0xf42/0x15f0 mm/mempolicy.c:1333\n   kernel_mbind mm/mempolicy.c:1483 [inline]\n   __do_sys_mbind mm/mempolicy.c:1490 [inline]\n   __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486\n   __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486\n   do_syscall_x64 arch/x86/entry/common.c:51 [inline]\n   do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82\n   entry_SYSCALL_64_after_hwframe+0x44/0xae\n\n  Uninit was created at:\n   slab_alloc_node mm/slub.c:3221 [inline]\n   slab_alloc mm/slub.c:3230 [inline]\n   kmem_cache_alloc+0x751/0xff0 mm/slub.c:3235\n   mpol_new mm/mempolicy.c:293 [inline]\n   do_mbind+0x912/0x15f0 mm/mempolicy.c:1289\n   kernel_mbind mm/mempolicy.c:1483 [inline]\n   __do_sys_mbind mm/mempolicy.c:1490 [inline]\n   __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486\n   __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486\n   do_syscall_x64 arch/x86/entry/common.c:51 [inline]\n   do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82\n   entry_SYSCALL_64_after_hwframe+0x44/0xae\n  =====================================================\n  Kernel panic - not syncing: panic_on_kmsan set ...\n  CPU: 0 PID: 15049 Comm: syz-executor.0 Tainted: G    B             5.15.0-rc2-syzkaller #0\n  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\n  Call Trace:\n   __dump_stack lib/dump_stack.c:88 [inline]\n   dump_stack_lvl+0x1ff/0x28e lib/dump_stack.c:106\n   dump_stack+0x25/0x28 lib/dump_stack.c:113\n   panic+0x44f/0xdeb kernel/panic.c:232\n   kmsan_report+0x2ee/0x300 mm/kmsan/report.c:186\n   __msan_warning+0xd7/0x150 mm/kmsan/instrumentation.c:208\n   __mpol_equal+0x567/0x590 mm/mempolicy.c:2260\n   mpol_equal include/linux/mempolicy.h:105 [inline]\n   vma_merge+0x4a1/0x1e60 mm/mmap.c:1190\n   mbind_range+0xcc8/0x1e80 mm/mempolicy.c:811\n   do_mbind+0xf42/0x15f0 mm/mempolicy.c:1333\n   kernel_mbind mm/mempolicy.c:1483 [inline]\n   __do_sys_mbind mm/mempolicy.c:1490 [inline]\n   __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486\n   __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486\n   do_syscall_x64 arch/x86/entry/common.c:51 [inline]\n   do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82\n   entry_SYSCALL_64_after_hwframe+0x44/0xae","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"mm/mempolicy: do not allow illegal MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind()","id":"CVE-2021-47462","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2021"},"n_packages":0,"n_references":2,"next":{"headline":"mm/secretmem: fix NULL page-\u003emapping dereference in page_is_secretmem()","id":"CVE-2021-47463"},"packages":[],"prev":{"headline":"userfaultfd: fix a race between writeprotect and exit_mmap()","id":"CVE-2021-47461"},"products":["Linux"],"published":"2024-05-22","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A local attacker can trigger a kernel panic via uninitialized memory access in the mbind system call, causing denial of service.","url":"https://insights.sbomify.com/CVE-2021-47462/"}