CVE-2021-47492

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2021-47492", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-22T06:20:56.201Z", "datePublished": "2024-05-22T08:19:40.759Z", "dateUpdated": "2026-08-05T08:48:02.710Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:48:02.710Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm, thp: bail out early in collapse_file for writeback page\n\nCurrently collapse_file does not explicitly check PG_writeback, instead,\npage_has_private and try_to_release_page are used to filter writeback\npages. This does not work for xfs with blocksize equal to or larger\nthan pagesize, because in such case xfs has no page->private.\n\nThis makes collapse_file bail out early for writeback page. Otherwise,\nxfs end_page_writeback will panic as follows.\n\n page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:ffff0003f88c86a8 index:0x0 pfn:0x84ef32\n aops:xfs_address_space_operations [xfs] ino:30000b7 dentry name:\"libtest.so\"\n flags: 0x57fffe0000008027(locked|referenced|uptodate|active|writeback)\n raw: 57fffe0000008027 ffff80001b48bc28 ffff80001b48bc28 ffff0003f88c86a8\n raw: 0000000000000000 0000000000000000 00000000ffffffff ffff0000c3e9a000\n page dumped because: VM_BUG_ON_PAGE(((unsigned int) page_ref_count(page) + 127u <= 127u))\n page->mem_cgroup:ffff0000c3e9a000\n ------------[ cut here ]------------\n kernel BUG at include/linux/mm.h:1212!\n Internal error: Oops - BUG: 0 [#1] SMP\n Modules linked in:\n BUG: Bad page state in process khugepaged pfn:84ef32\n xfs(E)\n page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:0 index:0x0 pfn:0x84ef32\n libcrc32c(E) rfkill(E) aes_ce_blk(E) crypto_simd(E) ...\n CPU: 25 PID: 0 Comm: swapper/25 Kdump: loaded Tainted: ...\n pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)\n Call trace:\n end_page_writeback+0x1c0/0x214\n iomap_finish_page_writeback+0x13c/0x204\n iomap_finish_ioend+0xe8/0x19c\n iomap_writepage_end_bio+0x38/0x50\n bio_endio+0x168/0x1ec\n blk_update_request+0x278/0x3f0\n blk_mq_end_request+0x34/0x15c\n virtblk_request_done+0x38/0x74 [virtio_blk]\n blk_done_softirq+0xc4/0x110\n __do_softirq+0x128/0x38c\n __irq_exit_rcu+0x118/0x150\n irq_exit+0x1c/0x30\n __handle_domain_irq+0x8c/0xf0\n gic_handle_irq+0x84/0x108\n el1_irq+0xcc/0x180\n arch_cpu_idle+0x18/0x40\n default_idle_call+0x4c/0x1a0\n cpuidle_idle_call+0x168/0x1e0\n do_idle+0xb4/0x104\n cpu_startup_entry+0x30/0x9c\n secondary_start_kernel+0x104/0x180\n Code: d4210000 b0006161 910c8021 94013f4d (d4210000)\n ---[ end trace 4a88c6a074082f8c ]---\n Kernel panic - not syncing: Oops - BUG: Fatal exception in interrupt"}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The bug is in mm/khugepaged.c collapse_file(), reached when khugepaged scans a local process's VM_EXEC file mapping registered via mmap/madvise(MADV_HUGEPAGE); it is not reachable from network packet or protocol processing.\nAC:L - An unprivileged attacker controls both sides: they can dirty an executable file on XFS, let khugepaged's own filemap_flush start writeback, and re-enter collapse via MADV_HUGEPAGE retries until a PG_writeback page without page->private is collapsed; no attacker-uncontrollable layout is required.\nPR:L - Any unprivileged local user can write a file on an XFS filesystem, map it PROT_EXEC while not open for write, and madvise(MADV_HUGEPAGE) to enroll the mm in khugepaged; no root or init-namespace capability is required.\nUI:N - The attacker performs the writes, executable mapping, and madvise against their own process; no separate victim action is needed.\nS:U - The resulting page use-after-free corrupts kernel pagecache/page-allocator state within the same kernel security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - collapse_file frees a still-under-writeback page (no page->private on XFS bs>=pagesize), and on production kernels without DEBUG_VM that page is placed on the PCP freelist while end_page_writeback still holds the pointer\u2014a page UAF that enables arbitrary kernel read primitives once reclaimed.\nI:H - end_page_writeback() then get_page/test_clear_page_writeback/put_page on the reallocated page, corrupting refcounts and PG_writeback on attacker-controlled page contents and yielding a heap UAF write/control-flow hijack primitive.\nA:H - The demonstrated effect is a kernel BUG/panic (VM_BUG_ON on zero refcount or BUG() in end_page_writeback when PG_writeback was already cleared), and any page UAF can oops the kernel even when not fully exploited."}]}], "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": "69a7fa5cb0de06c8956b040f19a7248c8c8308ca", "status": "affected", "versionType": "git"}, {"version": "99cb0dbd47a15d395bf3faa78dc122bc5efe3fc0", "lessThan": "5e669d8ab30ab61dec3c36e27b4711f07611e6fc", "status": "affected", "versionType": "git"}, {"version": "99cb0dbd47a15d395bf3faa78dc122bc5efe3fc0", "lessThan": "74c42e1baacf206338b1dd6b6199ac964512b5bb", "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": "5.10.77", "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": "5.10.77"}, {"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/69a7fa5cb0de06c8956b040f19a7248c8c8308ca"}, {"url": "https://git.kernel.org/stable/c/5e669d8ab30ab61dec3c36e27b4711f07611e6fc"}, {"url": "https://git.kernel.org/stable/c/74c42e1baacf206338b1dd6b6199ac964512b5bb"}], "title": "mm, thp: bail out early in collapse_file for writeback page", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-47492", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-05-22T19:45:29.189112Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-04T17:14:55.710Z"}}, {"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:39:59.622Z"}, "title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/69a7fa5cb0de06c8956b040f19a7248c8c8308ca", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/5e669d8ab30ab61dec3c36e27b4711f07611e6fc", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/74c42e1baacf206338b1dd6b6199ac964512b5bb", "tags": ["x_transferred"]}]}]}}

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This does not work for xfs with blocksize equal to or larger\nthan pagesize, because in such case xfs has no page->private.\n\nThis makes collapse_file bail out early for writeback page. Otherwise,\nxfs end_page_writeback will panic as follows.\n\n page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:ffff0003f88c86a8 index:0x0 pfn:0x84ef32\n aops:xfs_address_space_operations [xfs] ino:30000b7 dentry name:\"libtest.so\"\n flags: 0x57fffe0000008027(locked|referenced|uptodate|active|writeback)\n raw: 57fffe0000008027 ffff80001b48bc28 ffff80001b48bc28 ffff0003f88c86a8\n raw: 0000000000000000 0000000000000000 00000000ffffffff ffff0000c3e9a000\n page dumped because: VM_BUG_ON_PAGE(((unsigned int) page_ref_count(page) + 127u <= 127u))\n page->mem_cgroup:ffff0000c3e9a000\n ------------[ cut here ]------------\n kernel BUG at include/linux/mm.h:1212!\n Internal error: Oops - BUG: 0 [#1] SMP\n Modules linked in:\n BUG: Bad page state in process khugepaged pfn:84ef32\n xfs(E)\n page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:0 index:0x0 pfn:0x84ef32\n libcrc32c(E) rfkill(E) aes_ce_blk(E) crypto_simd(E) ...\n CPU: 25 PID: 0 Comm: swapper/25 Kdump: loaded Tainted: ...\n pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)\n Call trace:\n end_page_writeback+0x1c0/0x214\n iomap_finish_page_writeback+0x13c/0x204\n iomap_finish_ioend+0xe8/0x19c\n iomap_writepage_end_bio+0x38/0x50\n bio_endio+0x168/0x1ec\n blk_update_request+0x278/0x3f0\n blk_mq_end_request+0x34/0x15c\n virtblk_request_done+0x38/0x74 [virtio_blk]\n blk_done_softirq+0xc4/0x110\n __do_softirq+0x128/0x38c\n __irq_exit_rcu+0x118/0x150\n irq_exit+0x1c/0x30\n __handle_domain_irq+0x8c/0xf0\n gic_handle_irq+0x84/0x108\n el1_irq+0xcc/0x180\n arch_cpu_idle+0x18/0x40\n default_idle_call+0x4c/0x1a0\n cpuidle_idle_call+0x168/0x1e0\n do_idle+0xb4/0x104\n cpu_startup_entry+0x30/0x9c\n secondary_start_kernel+0x104/0x180\n Code: d4210000 b0006161 910c8021 94013f4d (d4210000)\n ---[ end trace 4a88c6a074082f8c ]---\n Kernel panic - not syncing: Oops - BUG: Fatal exception in interrupt"}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.10.77", "versionStartIncluding": "5.4"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.14.16", "versionStartIncluding": "5.4"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15", "versionStartIncluding": "5.4"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-04T09:00:57.207Z"}}}, "cveMetadata": {"cveId": "CVE-2021-47492", "state": "PUBLISHED", "dateUpdated": "2026-08-04T09:00:57.207Z", "dateReserved": "2024-05-22T06:20:56.201Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-05-22T08:19:40.759Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["mm/khugepaged.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "69a7fa5cb0de06c8956b040f19a7248c8c8308ca", "status": "affected", "version": "99cb0dbd47a15d395bf3faa78dc122bc5efe3fc0", "versionType": "git"}, {"lessThan": "5e669d8ab30ab61dec3c36e27b4711f07611e6fc", "status": "affected", "version": "99cb0dbd47a15d395bf3faa78dc122bc5efe3fc0", "versionType": "git"}, {"lessThan": "74c42e1baacf206338b1dd6b6199ac964512b5bb", "status": "affected", "version": "99cb0dbd47a15d395bf3faa78dc122bc5efe3fc0", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["mm/khugepaged.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.4"}, {"lessThan": "5.4", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.77", "versionType": "semver"}, {"lessThanOrEqual": "5.14.*", "status": "unaffected", "version": "5.14.16", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "5.15", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "6EF3E26D-A1EF-4DE4-B0D3-23ADF141E2C5", "versionEndExcluding": "5.10.77", "versionStartIncluding": "5.4", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "2681B950-4548-4649-A9E1-4124B59FC09C", "versionEndExcluding": "5.14.16", "versionStartIncluding": "5.11", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*", "matchCriteriaId": "E46C74C6-B76B-4C94-A6A4-FD2FFF62D644", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*", "matchCriteriaId": "60134C3A-06E4-48C1-B04F-2903732A4E56", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*", "matchCriteriaId": "0460DA88-8FE1-46A2-9DDA-1F1ABA552E71", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:*", "matchCriteriaId": "AF55383D-4DF2-45DC-93F7-571F4F978EAB", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:*", "matchCriteriaId": "9E9481B2-8AA6-4CBD-B5D3-C10F51FF6D01", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc6:*:*:*:*:*:*", "matchCriteriaId": "EBD45831-4B79-42BC-ABC0-86870F0DEA89", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc7:*:*:*:*:*:*", "matchCriteriaId": "948A6B8D-1B72-4945-8680-354E53BE1C80", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm, thp: bail out early in collapse_file for writeback page\n\nCurrently collapse_file does not explicitly check PG_writeback, instead,\npage_has_private and try_to_release_page are used to filter writeback\npages. This does not work for xfs with blocksize equal to or larger\nthan pagesize, because in such case xfs has no page->private.\n\nThis makes collapse_file bail out early for writeback page. Otherwise,\nxfs end_page_writeback will panic as follows.\n\n page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:ffff0003f88c86a8 index:0x0 pfn:0x84ef32\n aops:xfs_address_space_operations [xfs] ino:30000b7 dentry name:\"libtest.so\"\n flags: 0x57fffe0000008027(locked|referenced|uptodate|active|writeback)\n raw: 57fffe0000008027 ffff80001b48bc28 ffff80001b48bc28 ffff0003f88c86a8\n raw: 0000000000000000 0000000000000000 00000000ffffffff ffff0000c3e9a000\n page dumped because: VM_BUG_ON_PAGE(((unsigned int) page_ref_count(page) + 127u <= 127u))\n page->mem_cgroup:ffff0000c3e9a000\n ------------[ cut here ]------------\n kernel BUG at include/linux/mm.h:1212!\n Internal error: Oops - BUG: 0 [#1] SMP\n Modules linked in:\n BUG: Bad page state in process khugepaged pfn:84ef32\n xfs(E)\n page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:0 index:0x0 pfn:0x84ef32\n libcrc32c(E) rfkill(E) aes_ce_blk(E) crypto_simd(E) ...\n CPU: 25 PID: 0 Comm: swapper/25 Kdump: loaded Tainted: ...\n pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)\n Call trace:\n end_page_writeback+0x1c0/0x214\n iomap_finish_page_writeback+0x13c/0x204\n iomap_finish_ioend+0xe8/0x19c\n iomap_writepage_end_bio+0x38/0x50\n bio_endio+0x168/0x1ec\n blk_update_request+0x278/0x3f0\n blk_mq_end_request+0x34/0x15c\n virtblk_request_done+0x38/0x74 [virtio_blk]\n blk_done_softirq+0xc4/0x110\n __do_softirq+0x128/0x38c\n __irq_exit_rcu+0x118/0x150\n irq_exit+0x1c/0x30\n __handle_domain_irq+0x8c/0xf0\n gic_handle_irq+0x84/0x108\n el1_irq+0xcc/0x180\n arch_cpu_idle+0x18/0x40\n default_idle_call+0x4c/0x1a0\n cpuidle_idle_call+0x168/0x1e0\n do_idle+0xb4/0x104\n cpu_startup_entry+0x30/0x9c\n secondary_start_kernel+0x104/0x180\n Code: d4210000 b0006161 910c8021 94013f4d (d4210000)\n ---[ end trace 4a88c6a074082f8c ]---\n Kernel panic - not syncing: Oops - BUG: Fatal exception in interrupt"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mm, thp: rescatar temprano en el colapso_archivo para la p\u00e1gina de reescritura. Actualmente, colapso_archivo no verifica expl\u00edcitamente PG_writeback; en su lugar, page_has_private y try_to_release_page se utilizan para filtrar las p\u00e1ginas de reescritura. Esto no funciona para xfs con un tama\u00f1o de bloque igual o mayor que el tama\u00f1o de p\u00e1gina, porque en tal caso xfs no tiene p\u00e1gina-&gt;privada. Esto hace que colapso_file salga anticipadamente de la p\u00e1gina de reescritura. De lo contrario, xfs end_page_writeback entrar\u00e1 en p\u00e1nico de la siguiente manera. p\u00e1gina:fffffe00201bcc80 refcount:0 mapcount:0 mapeo:ffff0003f88c86a8 \u00edndice:0x0 pfn:0x84ef32 aops:xfs_address_space_operaciones [xfs] ino:30000b7 nombre dentry:\"libtest.so\" banderas: 0x57fffe0000008027(bloqueado|referenciado| actualizaci\u00f3n|activo|reescritura) sin formato : 57fffe0000008027 ffff80001b48bc28 ffff80001b48bc28 ffff0003f88c86a8 crudo: 0000000000000000 00000000000000000 00000000ffffffff p\u00e1gina volcada porque: VM_BUG_ON_PAGE(((unsigned int) page_ref_count(page) + 127u &lt;= 127u)) page-&gt;mem_cgroup:ffff0000c3e9a000 ----------- -[ cortar aqu\u00ed ]------------ \u00a1ERROR del kernel en include/linux/mm.h:1212! Error interno: Ups - ERROR: 0 [#1] M\u00f3dulos SMP vinculados en: ERROR: Estado de p\u00e1gina incorrecto en el proceso khugepaged pfn:84ef32 xfs(E) page:fffffe00201bcc80 refcount:0 mapcount:0 mapeo:0 index:0x0 pfn:0x84ef32 libcrc32c(E) rfkill(E) aes_ce_blk(E) crypto_simd(E) ... CPU: 25 PID: 0 Comm: swapper/25 Kdump: cargado Contaminado: ... pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--) Seguimiento de llamadas: end_page_writeback+0x1c0/0x214 iomap_finish_page_writeback+0x13c/0x204 iomap_finish_ioend+0xe8/0x19c iomap_writepage_end_bio+0x38/0x50 bio_endio+0x168/0x1ec blk_update_request+0x278/0x 3f0 blk_mq_end_request+0x34/0x15c virtblk_request_done+0x38/0x74 [virtio_blk ] blk_done_softirq+0xc4/0x110 __do_softirq+0x128/0x38c __irq_exit_rcu+0x118/0x150 irq_exit+0x1c/0x30 __handle_domain_irq+0x8c/0xf0 gic_handle_irq+0x84/0x108 xcc/0x180 arch_cpu_idle+0x18/0x40 default_idle_call+0x4c/0x1a0 cpuidle_idle_call+0x168/ 0x1e0 do_idle+0xb4/0x104 cpu_startup_entry+0x30/0x9c second_start_kernel+0x104/0x180 C\u00f3digo: d4210000 b0006161 910c8021 94013f4d (d4210000) ---[ end trace 4a88c6a074082f 8c ]--- P\u00e1nico en el kernel - no se sincroniza: Ups - ERROR: excepci\u00f3n fatal en la interrupci\u00f3n"}], "id": "CVE-2021-47492", "lastModified": "2026-08-04T10:17:05.447", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2021-47492", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2024-05-22T19:45:29.189112Z", "version": "2.0.3"}}]}, "published": "2024-05-22T09:15:11.030", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/5e669d8ab30ab61dec3c36e27b4711f07611e6fc"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/69a7fa5cb0de06c8956b040f19a7248c8c8308ca"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/74c42e1baacf206338b1dd6b6199ac964512b5bb"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/5e669d8ab30ab61dec3c36e27b4711f07611e6fc"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/69a7fa5cb0de06c8956b040f19a7248c8c8308ca"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/74c42e1baacf206338b1dd6b6199ac964512b5bb"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"affected_release": [{"advisory": "RHSA-2024:6753", "cpe": "cpe:/o:redhat:rhel_aus:8.6", "package": "kernel-0:4.18.0-372.123.1.el8_6", "product_name": "Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support", "release_date": "2024-09-18T00:00:00Z"}, {"advisory": "RHSA-2024:6753", "cpe": "cpe:/o:redhat:rhel_tus:8.6", "package": "kernel-0:4.18.0-372.123.1.el8_6", "product_name": "Red Hat Enterprise Linux 8.6 Telecommunications Update Service", "release_date": "2024-09-18T00:00:00Z"}, {"advisory": "RHSA-2024:6753", "cpe": "cpe:/o:redhat:rhel_e4s:8.6", "package": "kernel-0:4.18.0-372.123.1.el8_6", "product_name": "Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions", "release_date": "2024-09-18T00:00:00Z"}], "bugzilla": {"description": "kernel: mm, thp: bail out early in collapse_file for writeback page", "id": "2282924", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2282924"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "verified"}, "cwe": "CWE-372", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nmm, thp: bail out early in collapse_file for writeback page\nCurrently collapse_file does not explicitly check PG_writeback, instead,\npage_has_private and try_to_release_page are used to filter writeback\npages. This does not work for xfs with blocksize equal to or larger\nthan pagesize, because in such case xfs has no page->private.\nThis makes collapse_file bail out early for writeback page. Otherwise,\nxfs end_page_writeback will panic as follows.\npage:fffffe00201bcc80 refcount:0 mapcount:0 mapping:ffff0003f88c86a8 index:0x0 pfn:0x84ef32\naops:xfs_address_space_operations [xfs] ino:30000b7 dentry name:\"libtest.so\"\nflags: 0x57fffe0000008027(locked|referenced|uptodate|active|writeback)\nraw: 57fffe0000008027 ffff80001b48bc28 ffff80001b48bc28 ffff0003f88c86a8\nraw: 0000000000000000 0000000000000000 00000000ffffffff ffff0000c3e9a000\npage dumped because: VM_BUG_ON_PAGE(((unsigned int) page_ref_count(page) + 127u <= 127u))\npage->mem_cgroup:ffff0000c3e9a000\n------------[ cut here ]------------\nkernel BUG at include/linux/mm.h:1212!\nInternal error: Oops - BUG: 0 [#1] SMP\nModules linked in:\nBUG: Bad page state in process khugepaged pfn:84ef32\nxfs(E)\npage:fffffe00201bcc80 refcount:0 mapcount:0 mapping:0 index:0x0 pfn:0x84ef32\nlibcrc32c(E) rfkill(E) aes_ce_blk(E) crypto_simd(E) ...\nCPU: 25 PID: 0 Comm: swapper/25 Kdump: loaded Tainted: ...\npstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)\nCall trace:\nend_page_writeback+0x1c0/0x214\niomap_finish_page_writeback+0x13c/0x204\niomap_finish_ioend+0xe8/0x19c\niomap_writepage_end_bio+0x38/0x50\nbio_endio+0x168/0x1ec\nblk_update_request+0x278/0x3f0\nblk_mq_end_request+0x34/0x15c\nvirtblk_request_done+0x38/0x74 [virtio_blk]\nblk_done_softirq+0xc4/0x110\n__do_softirq+0x128/0x38c\n__irq_exit_rcu+0x118/0x150\nirq_exit+0x1c/0x30\n__handle_domain_irq+0x8c/0xf0\ngic_handle_irq+0x84/0x108\nel1_irq+0xcc/0x180\narch_cpu_idle+0x18/0x40\ndefault_idle_call+0x4c/0x1a0\ncpuidle_idle_call+0x168/0x1e0\ndo_idle+0xb4/0x104\ncpu_startup_entry+0x30/0x9c\nsecondary_start_kernel+0x104/0x180\nCode: d4210000 b0006161 910c8021 94013f4d (d4210000)\n---[ end trace 4a88c6a074082f8c ]---\nKernel panic - not syncing: Oops - BUG: Fatal exception in interrupt"], "name": "CVE-2021-47492", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-05-22T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-47492\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47492\nhttps://lore.kernel.org/linux-cve-announce/2024052241-CVE-2021-47492-ee88@gregkh/T"], "threat_severity": "Moderate"}

{}