{"id":"CVE-2021-47623","state":"PUBLISHED","title":"powerpc/fixmap: Fix VM debug warning on unmap","description":"In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/fixmap: Fix VM debug warning on unmap\n\nUnmapping a fixmap entry is done by calling __set_fixmap()\nwith FIXMAP_PAGE_CLEAR as flags.\n\nToday, powerpc __set_fixmap() calls map_kernel_page().\n\nmap_kernel_page() is not happy when called a second time\nfor the same page.\n\n\tWARNING: CPU: 0 PID: 1 at arch/powerpc/mm/pgtable.c:194 set_pte_at+0xc/0x1e8\n\tCPU: 0 PID: 1 Comm: swapper Not tainted 5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty #682\n\tNIP:  c0017cd4 LR: c00187f0 CTR: 00000010\n\tREGS: e1011d50 TRAP: 0700   Not tainted  (5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty)\n\tMSR:  00029032 <EE,ME,IR,DR,RI>  CR: 42000208  XER: 00000000\n\n\tGPR00: c0165fec e1011e10 c14c0000 c0ee2550 ff800000 c0f3d000 00000000 c001686c\n\tGPR08: 00001000 b00045a9 00000001 c0f58460 c0f50000 00000000 c0007e10 00000000\n\tGPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000\n\tGPR24: 00000000 00000000 c0ee2550 00000000 c0f57000 00000ff8 00000000 ff800000\n\tNIP [c0017cd4] set_pte_at+0xc/0x1e8\n\tLR [c00187f0] map_kernel_page+0x9c/0x100\n\tCall Trace:\n\t[e1011e10] [c0736c68] vsnprintf+0x358/0x6c8 (unreliable)\n\t[e1011e30] [c0165fec] __set_fixmap+0x30/0x44\n\t[e1011e40] [c0c13bdc] early_iounmap+0x11c/0x170\n\t[e1011e70] [c0c06cb0] ioremap_legacy_serial_console+0x88/0xc0\n\t[e1011e90] [c0c03634] do_one_initcall+0x80/0x178\n\t[e1011ef0] [c0c0385c] kernel_init_freeable+0xb4/0x250\n\t[e1011f20] [c0007e34] kernel_init+0x24/0x140\n\t[e1011f30] [c0016268] ret_from_kernel_thread+0x5c/0x64\n\tInstruction dump:\n\t7fe3fb78 48019689 80010014 7c630034 83e1000c 5463d97e 7c0803a6 38210010\n\t4e800020 81250000 712a0001 41820008 <0fe00000> 9421ffe0 93e1001c 48000030\n\nImplement unmap_kernel_page() which clears an existing pte.","publishedAt":"2024-07-16T11:29:39.071Z","updatedAt":"2026-05-11T13:58:05.571Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"265c3491c4bc8d40587996d6ee2f447a7ccfb4f3","status":"affected","lessThan":"67baac10dd5ad1e9f50e8f2659984b3b0728d54e","versionType":"git"},{"version":"265c3491c4bc8d40587996d6ee2f447a7ccfb4f3","status":"affected","lessThan":"43ae0ccc4d2722b833fb59b905af129428e06d03","versionType":"git"},{"version":"265c3491c4bc8d40587996d6ee2f447a7ccfb4f3","status":"affected","lessThan":"033fd42c18d9b2121595b6f1e8419a115f9ac5b7","versionType":"git"},{"version":"265c3491c4bc8d40587996d6ee2f447a7ccfb4f3","status":"affected","lessThan":"aec982603aa8cc0a21143681feb5f60ecc69d718","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/powerpc/include/asm/book3s/32/pgtable.h","arch/powerpc/include/asm/book3s/64/pgtable.h","arch/powerpc/include/asm/fixmap.h","arch/powerpc/include/asm/nohash/32/pgtable.h","arch/powerpc/include/asm/nohash/64/pgtable.h","arch/powerpc/mm/pgtable.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.5","versionType":"semver"},{"version":"5.10.101","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.24","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16.10","status":"unaffected","lessThanOrEqual":"5.16.*","versionType":"semver"},{"version":"5.17","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/powerpc/include/asm/book3s/32/pgtable.h","arch/powerpc/include/asm/book3s/64/pgtable.h","arch/powerpc/include/asm/fixmap.h","arch/powerpc/include/asm/nohash/32/pgtable.h","arch/powerpc/include/asm/nohash/64/pgtable.h","arch/powerpc/mm/pgtable.c"]}],"references":["https://git.kernel.org/stable/c/67baac10dd5ad1e9f50e8f2659984b3b0728d54e","https://git.kernel.org/stable/c/43ae0ccc4d2722b833fb59b905af129428e06d03","https://git.kernel.org/stable/c/033fd42c18d9b2121595b6f1e8419a115f9ac5b7","https://git.kernel.org/stable/c/aec982603aa8cc0a21143681feb5f60ecc69d718"],"weaknesses":[],"ingestedAt":"2026-10-29T19:49:19.404Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/47xxx/CVE-2021-47623.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47623","state":"PUBLISHED","datePublished":"2024-07-16T11:29:39.071Z","dateUpdated":"2026-05-11T13:58:05.571Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-07-16T11:26:52.956Z"},"containers":{"cna":{"title":"powerpc/fixmap: Fix VM debug warning on unmap","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/fixmap: Fix VM debug warning on unmap\n\nUnmapping a fixmap entry is done by calling __set_fixmap()\nwith FIXMAP_PAGE_CLEAR as flags.\n\nToday, powerpc __set_fixmap() calls map_kernel_page().\n\nmap_kernel_page() is not happy when called a second time\nfor the same page.\n\n\tWARNING: CPU: 0 PID: 1 at arch/powerpc/mm/pgtable.c:194 set_pte_at+0xc/0x1e8\n\tCPU: 0 PID: 1 Comm: swapper Not tainted 5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty #682\n\tNIP:  c0017cd4 LR: c00187f0 CTR: 00000010\n\tREGS: e1011d50 TRAP: 0700   Not tainted  (5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty)\n\tMSR:  00029032 <EE,ME,IR,DR,RI>  CR: 42000208  XER: 00000000\n\n\tGPR00: c0165fec e1011e10 c14c0000 c0ee2550 ff800000 c0f3d000 00000000 c001686c\n\tGPR08: 00001000 b00045a9 00000001 c0f58460 c0f50000 00000000 c0007e10 00000000\n\tGPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000\n\tGPR24: 00000000 00000000 c0ee2550 00000000 c0f57000 00000ff8 00000000 ff800000\n\tNIP [c0017cd4] set_pte_at+0xc/0x1e8\n\tLR [c00187f0] map_kernel_page+0x9c/0x100\n\tCall Trace:\n\t[e1011e10] [c0736c68] vsnprintf+0x358/0x6c8 (unreliable)\n\t[e1011e30] [c0165fec] __set_fixmap+0x30/0x44\n\t[e1011e40] [c0c13bdc] early_iounmap+0x11c/0x170\n\t[e1011e70] [c0c06cb0] ioremap_legacy_serial_console+0x88/0xc0\n\t[e1011e90] [c0c03634] do_one_initcall+0x80/0x178\n\t[e1011ef0] [c0c0385c] kernel_init_freeable+0xb4/0x250\n\t[e1011f20] [c0007e34] kernel_init+0x24/0x140\n\t[e1011f30] [c0016268] ret_from_kernel_thread+0x5c/0x64\n\tInstruction dump:\n\t7fe3fb78 48019689 80010014 7c630034 83e1000c 5463d97e 7c0803a6 38210010\n\t4e800020 81250000 712a0001 41820008 <0fe00000> 9421ffe0 93e1001c 48000030\n\nImplement unmap_kernel_page() which clears an existing pte."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"265c3491c4bc8d40587996d6ee2f447a7ccfb4f3","status":"affected","lessThan":"67baac10dd5ad1e9f50e8f2659984b3b0728d54e","versionType":"git"},{"version":"265c3491c4bc8d40587996d6ee2f447a7ccfb4f3","status":"affected","lessThan":"43ae0ccc4d2722b833fb59b905af129428e06d03","versionType":"git"},{"version":"265c3491c4bc8d40587996d6ee2f447a7ccfb4f3","status":"affected","lessThan":"033fd42c18d9b2121595b6f1e8419a115f9ac5b7","versionType":"git"},{"version":"265c3491c4bc8d40587996d6ee2f447a7ccfb4f3","status":"affected","lessThan":"aec982603aa8cc0a21143681feb5f60ecc69d718","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/powerpc/include/asm/book3s/32/pgtable.h","arch/powerpc/include/asm/book3s/64/pgtable.h","arch/powerpc/include/asm/fixmap.h","arch/powerpc/include/asm/nohash/32/pgtable.h","arch/powerpc/include/asm/nohash/64/pgtable.h","arch/powerpc/mm/pgtable.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.5","versionType":"semver"},{"version":"5.10.101","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.24","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16.10","status":"unaffected","lessThanOrEqual":"5.16.*","versionType":"semver"},{"version":"5.17","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/powerpc/include/asm/book3s/32/pgtable.h","arch/powerpc/include/asm/book3s/64/pgtable.h","arch/powerpc/include/asm/fixmap.h","arch/powerpc/include/asm/nohash/32/pgtable.h","arch/powerpc/include/asm/nohash/64/pgtable.h","arch/powerpc/mm/pgtable.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/67baac10dd5ad1e9f50e8f2659984b3b0728d54e"},{"url":"https://git.kernel.org/stable/c/43ae0ccc4d2722b833fb59b905af129428e06d03"},{"url":"https://git.kernel.org/stable/c/033fd42c18d9b2121595b6f1e8419a115f9ac5b7"},{"url":"https://git.kernel.org/stable/c/aec982603aa8cc0a21143681feb5f60ecc69d718"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T13:58:05.571Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.10.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.15.24"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.16.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.17"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE 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