{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2021-47414","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-05-21T14:58:30.818Z","datePublished":"2024-05-21T15:04:04.715Z","dateUpdated":"2025-05-04T07:10:25.725Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2025-05-04T07:10:25.725Z"},"descriptions":[{"lang":"en","value":"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] [<ffffffff80007240>] riscv_cpuid_to_hartid_mask+0x6/0xae\n[    0.000000] [<ffffffff80009474>] sbi_remote_fence_i+0x1e/0x26\n[    0.000000] [<ffffffff8000b8f4>] flush_icache_all+0x12/0x1a\n[    0.000000] [<ffffffff8000666c>] patch_text_nosync+0x26/0x32\n[    0.000000] [<ffffffff8000884e>] ftrace_init_nop+0x52/0x8c\n[    0.000000] [<ffffffff800f051e>] ftrace_process_locs.isra.0+0x29c/0x360\n[    0.000000] [<ffffffff80a0e3c6>] ftrace_init+0x80/0x130\n[    0.000000] [<ffffffff80a00f8c>] 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 -> flush_icache_all\n                   -> sbi_remote_fence_i\n                   -> __sbi_rfence_v02\n                   -> 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."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/riscv/mm/cacheflush.c"],"versions":[{"version":"fab957c11efe2f405e08b9f0d080524bc2631428","lessThan":"427faa29e06f0709476ea1bd59758f997ec8b64e","status":"affected","versionType":"git"},{"version":"fab957c11efe2f405e08b9f0d080524bc2631428","lessThan":"f1c7aa87c423e765e3862349c2f095fdfccdd9b3","status":"affected","versionType":"git"},{"version":"fab957c11efe2f405e08b9f0d080524bc2631428","lessThan":"bb8958d5dc79acbd071397abb57b8756375fe1ce","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/riscv/mm/cacheflush.c"],"versions":[{"version":"4.15","status":"affected"},{"version":"0","lessThan":"4.15","status":"unaffected","versionType":"semver"},{"version":"5.10.73","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.14.12","lessThanOrEqual":"5.14.*","status":"unaffected","versionType":"semver"},{"version":"5.15","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":"4.15","versionEndExcluding":"5.10.73"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"5.14.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"5.15"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/427faa29e06f0709476ea1bd59758f997ec8b64e"},{"url":"https://git.kernel.org/stable/c/f1c7aa87c423e765e3862349c2f095fdfccdd9b3"},{"url":"https://git.kernel.org/stable/c/bb8958d5dc79acbd071397abb57b8756375fe1ce"}],"title":"riscv: Flush current cpu icache before other cpus","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2021-47414","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-05-23T17:52:58.625321Z"}}}],"providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-06-04T17:13:41.022Z"}},{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-04T05:39:59.118Z"},"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/427faa29e06f0709476ea1bd59758f997ec8b64e","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/f1c7aa87c423e765e3862349c2f095fdfccdd9b3","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/bb8958d5dc79acbd071397abb57b8756375fe1ce","tags":["x_transferred"]}]}]}}