{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47414 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47414 is a medium-severity vulnerability in Linux kernel, published on 21 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-2021-47414 and fix it if it is affected.\n\nWhat it is: CVE-2021-47414 is a medium-severity vulnerability in Linux kernel, published on 21 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-2021-47414 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-2021-47414/ (Markdown: https://insights.sbomify.com/CVE-2021-47414/index.md)","id":"CVE-2021-47414","markdown":"https://insights.sbomify.com/CVE-2021-47414/index.md","name":"CVE-2021-47414","record":{"aliases":["DEBIAN-CVE-2021-47414","GHSA-whrp-vxvh-9rj2","UBUNTU-CVE-2021-47414"],"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 race condition in the Linux kernel RISC-V icache flushing can cause a system crash during boot on specific hardware.","user_interaction":"not_required","vuln_class":"race_condition"},"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":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nriscv: Flush current cpu icache before other cpus\n\nOn SiFive Unmatched, I recently fell onto the following BUG when booting:\n\n[    0.000000] ftrace: allocating 36610 entries in 144 pages\n[    0.000000] Oops - illegal instruction [#1]\n[    0.000000] Modules linked in:\n[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.13.1+ #5\n[    0.000000] Hardware name: SiFive HiFive Unmatched A00 (DT)\n[    0.000000] epc : riscv_cpuid_to_hartid_mask+0x6/0xae\n[    0.000000]  ra : __sbi_rfence_v02+0xc8/0x10a\n[    0.000000] epc : ffffffff80007240 ra : ffffffff80009964 sp : ffffffff81803e10\n[    0.000000]  gp : ffffffff81a1ea70 tp : ffffffff8180f500 t0 : ffffffe07fe30000\n[    0.000000]  t1 : 0000000000000004 t2 : 0000000000000000 s0 : ffffffff81803e60\n[    0.000000]  s1 : 0000000000000000 a0 : ffffffff81a22238 a1 : ffffffff81803e10\n[    0.000000]  a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000\n[    0.000000]  a5 : 0000000000000000 a6 : ffffffff8000989c a7 : 0000000052464e43\n[    0.000000]  s2 : ffffffff81a220c8 s3 : 0000000000000000 s4 : 0000000000000000\n[    0.000000]  s5 : 0000000000000000 s6 : 0000000200000100 s7 : 0000000000000001\n[    0.000000]  s8 : ffffffe07fe04040 s9 : ffffffff81a22c80 s10: 0000000000001000\n[    0.000000]  s11: 0000000000000004 t3 : 0000000000000001 t4 : 0000000000000008\n[    0.000000]  t5 : ffffffcf04000808 t6 : ffffffe3ffddf188\n[    0.000000] status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000002\n[    0.000000] [\u003cffffffff80007240\u003e] riscv_cpuid_to_hartid_mask+0x6/0xae\n[    0.000000] [\u003cffffffff80009474\u003e] sbi_remote_fence_i+0x1e/0x26\n[    0.000000] [\u003cffffffff8000b8f4\u003e] flush_icache_all+0x12/0x1a\n[    0.000000] [\u003cffffffff8000666c\u003e] patch_text_nosync+0x26/0x32\n[    0.000000] [\u003cffffffff8000884e\u003e] ftrace_init_nop+0x52/0x8c\n[    0.000000] [\u003cffffffff800f051e\u003e] ftrace_process_locs.isra.0+0x29c/0x360\n[    0.000000] [\u003cffffffff80a0e3c6\u003e] ftrace_init+0x80/0x130\n[    0.000000] [\u003cffffffff80a00f8c\u003e] start_kernel+0x5c4/0x8f6\n[    0.000000] ---[ end trace f67eb9af4d8d492b ]---\n[    0.000000] Kernel panic - not syncing: Attempted to kill the idle task!\n[    0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---\n\nWhile ftrace is looping over a list of addresses to patch, it always failed\nwhen patching the same function: riscv_cpuid_to_hartid_mask. Looking at the\nbacktrace, the illegal instruction is encountered in this same function.\nHowever, patch_text_nosync, after patching the instructions, calls\nflush_icache_range. But looking at what happens in this function:\n\nflush_icache_range -\u003e flush_icache_all\n                   -\u003e sbi_remote_fence_i\n                   -\u003e __sbi_rfence_v02\n                   -\u003e riscv_cpuid_to_hartid_mask\n\nThe icache and dcache of the current cpu are never synchronized between the\npatching of riscv_cpuid_to_hartid_mask and calling this same function.\n\nSo fix this by flushing the current cpu's icache before asking for the other\ncpus to do the same.","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":"riscv: Flush current cpu icache before other cpus","id":"CVE-2021-47414","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"race_condition","year":"2021"},"n_packages":0,"n_references":3,"next":{"headline":"iwlwifi: mvm: Fix possible NULL dereference","id":"CVE-2021-47415"},"packages":[],"prev":{"headline":"usb: chipidea: ci_hdrc_imx: Also search for 'phys' phandle","id":"CVE-2021-47413"},"products":["Linux"],"published":"2024-05-21","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":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A race condition in the Linux kernel RISC-V icache flushing can cause a system crash during boot on specific hardware.","url":"https://insights.sbomify.com/CVE-2021-47414/"}