{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2021-47491","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-05-22T06:20:56.201Z","datePublished":"2024-05-22T08:19:40.101Z","dateUpdated":"2025-05-04T07:12:11.704Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2025-05-04T07:12:11.704Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: khugepaged: skip huge page collapse for special files\n\nThe read-only THP for filesystems will collapse THP for files opened\nreadonly and mapped with VM_EXEC.  The intended usecase is to avoid TLB\nmisses for large text segments.  But it doesn't restrict the file types\nso a THP could be collapsed for a non-regular file, for example, block\ndevice, if it is opened readonly and mapped with EXEC permission.  This\nmay cause bugs, like [1] and [2].\n\nThis is definitely not the intended usecase, so just collapse THP for\nregular files in order to close the attack surface.\n\n[shy828301@gmail.com: fix vm_file check [3]]"}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/khugepaged.c"],"versions":[{"version":"99cb0dbd47a15d395bf3faa78dc122bc5efe3fc0","lessThan":"6d67b2a73b8e3a079c355bab3c1aef7d85a044b8","status":"affected","versionType":"git"},{"version":"99cb0dbd47a15d395bf3faa78dc122bc5efe3fc0","lessThan":"5fcb6fce74ffa614d964667110cf1a516c48c6d9","status":"affected","versionType":"git"},{"version":"99cb0dbd47a15d395bf3faa78dc122bc5efe3fc0","lessThan":"a4aeaa06d45e90f9b279f0b09de84bd00006e733","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/khugepaged.c"],"versions":[{"version":"5.4","status":"affected"},{"version":"0","lessThan":"5.4","status":"unaffected","versionType":"semver"},{"version":"5.10.78","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.14.16","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":"5.4","versionEndExcluding":"5.10.78"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4","versionEndExcluding":"5.14.16"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4","versionEndExcluding":"5.15"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/6d67b2a73b8e3a079c355bab3c1aef7d85a044b8"},{"url":"https://git.kernel.org/stable/c/5fcb6fce74ffa614d964667110cf1a516c48c6d9"},{"url":"https://git.kernel.org/stable/c/a4aeaa06d45e90f9b279f0b09de84bd00006e733"}],"title":"mm: khugepaged: skip huge page collapse for special files","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2021-47491","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-05-22T18:42:55.199651Z"}}}],"providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-06-04T17:13:59.526Z"}},{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-04T05:39:59.599Z"},"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/6d67b2a73b8e3a079c355bab3c1aef7d85a044b8","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/5fcb6fce74ffa614d964667110cf1a516c48c6d9","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/a4aeaa06d45e90f9b279f0b09de84bd00006e733","tags":["x_transferred"]}]}]}}