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CVE-2021-47637 (GCVE-0-2021-47637)

Vulnerability from cvelistv5 – Published: 2025-02-26 01:54 – Updated: 2026-05-11 13:58
VLAI
Title
ubifs: Fix deadlock in concurrent rename whiteout and inode writeback
Summary
In the Linux kernel, the following vulnerability has been resolved: ubifs: Fix deadlock in concurrent rename whiteout and inode writeback Following hung tasks: [ 77.028764] task:kworker/u8:4 state:D stack: 0 pid: 132 [ 77.028820] Call Trace: [ 77.029027] schedule+0x8c/0x1b0 [ 77.029067] mutex_lock+0x50/0x60 [ 77.029074] ubifs_write_inode+0x68/0x1f0 [ubifs] [ 77.029117] __writeback_single_inode+0x43c/0x570 [ 77.029128] writeback_sb_inodes+0x259/0x740 [ 77.029148] wb_writeback+0x107/0x4d0 [ 77.029163] wb_workfn+0x162/0x7b0 [ 92.390442] task:aa state:D stack: 0 pid: 1506 [ 92.390448] Call Trace: [ 92.390458] schedule+0x8c/0x1b0 [ 92.390461] wb_wait_for_completion+0x82/0xd0 [ 92.390469] __writeback_inodes_sb_nr+0xb2/0x110 [ 92.390472] writeback_inodes_sb_nr+0x14/0x20 [ 92.390476] ubifs_budget_space+0x705/0xdd0 [ubifs] [ 92.390503] do_rename.cold+0x7f/0x187 [ubifs] [ 92.390549] ubifs_rename+0x8b/0x180 [ubifs] [ 92.390571] vfs_rename+0xdb2/0x1170 [ 92.390580] do_renameat2+0x554/0x770 , are caused by concurrent rename whiteout and inode writeback processes: rename_whiteout(Thread 1) wb_workfn(Thread2) ubifs_rename do_rename lock_4_inodes (Hold ui_mutex) ubifs_budget_space make_free_space shrink_liability __writeback_inodes_sb_nr bdi_split_work_to_wbs (Queue new wb work) wb_do_writeback(wb work) __writeback_single_inode ubifs_write_inode LOCK(ui_mutex) ↑ wb_wait_for_completion (Wait wb work) <-- deadlock! Reproducer (Detail program in [Link]): 1. SYS_renameat2("/mp/dir/file", "/mp/dir/whiteout", RENAME_WHITEOUT) 2. Consume out of space before kernel(mdelay) doing budget for whiteout Fix it by doing whiteout space budget before locking ubifs inodes. BTW, it also fixes wrong goto tag 'out_release' in whiteout budget error handling path(It should at least recover dir i_size and unlock 4 ubifs inodes).
Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-10-01 19:50 UTC
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 , < 9dddc8211430fb851ddf0b168e3a00c6f66cc185 (git)
Affected: 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 , < 37bdf1ad592555ecda1d55b89f6e393e4c0589d1 (git)
Affected: 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 , < 83e42a78428fc354f5e2049935b84c8d8d29b787 (git)
Affected: 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 , < c58af8564a7b08757173009030b74baf4b2b762b (git)
Affected: 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 , < 70e9090acc32348cedc5def0cd6d5c126efc97b9 (git)
Affected: 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 , < 8b278c8dcfb565cb65eceb62a38cbf7a7c326db5 (git)
Affected: 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 , < afd427048047e8efdedab30e8888044e2be5aa9c (git)
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Linux Linux Affected: 4.9
Unaffected: 0 , < 4.9 (semver)
Unaffected: 4.19.238 , ≤ 4.19.* (semver)
Unaffected: 5.4.189 , ≤ 5.4.* (semver)
Unaffected: 5.10.110 , ≤ 5.10.* (semver)
Unaffected: 5.15.33 , ≤ 5.15.* (semver)
Unaffected: 5.16.19 , ≤ 5.16.* (semver)
Unaffected: 5.17.2 , ≤ 5.17.* (semver)
Unaffected: 5.18 , ≤ * (original_commit_for_fix)
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              "confidentialityImpact": "NONE",
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nubifs: Fix deadlock in concurrent rename whiteout and inode writeback\n\nFollowing hung tasks:\n[   77.028764] task:kworker/u8:4    state:D stack:    0 pid:  132\n[   77.028820] Call Trace:\n[   77.029027]  schedule+0x8c/0x1b0\n[   77.029067]  mutex_lock+0x50/0x60\n[   77.029074]  ubifs_write_inode+0x68/0x1f0 [ubifs]\n[   77.029117]  __writeback_single_inode+0x43c/0x570\n[   77.029128]  writeback_sb_inodes+0x259/0x740\n[   77.029148]  wb_writeback+0x107/0x4d0\n[   77.029163]  wb_workfn+0x162/0x7b0\n\n[   92.390442] task:aa              state:D stack:    0 pid: 1506\n[   92.390448] Call Trace:\n[   92.390458]  schedule+0x8c/0x1b0\n[   92.390461]  wb_wait_for_completion+0x82/0xd0\n[   92.390469]  __writeback_inodes_sb_nr+0xb2/0x110\n[   92.390472]  writeback_inodes_sb_nr+0x14/0x20\n[   92.390476]  ubifs_budget_space+0x705/0xdd0 [ubifs]\n[   92.390503]  do_rename.cold+0x7f/0x187 [ubifs]\n[   92.390549]  ubifs_rename+0x8b/0x180 [ubifs]\n[   92.390571]  vfs_rename+0xdb2/0x1170\n[   92.390580]  do_renameat2+0x554/0x770\n\n, are caused by concurrent rename whiteout and inode writeback processes:\n\trename_whiteout(Thread 1)\t        wb_workfn(Thread2)\nubifs_rename\n  do_rename\n    lock_4_inodes (Hold ui_mutex)\n    ubifs_budget_space\n      make_free_space\n        shrink_liability\n\t  __writeback_inodes_sb_nr\n\t    bdi_split_work_to_wbs (Queue new wb work)\n\t\t\t\t\t      wb_do_writeback(wb work)\n\t\t\t\t\t\t__writeback_single_inode\n\t\t\t\t\t          ubifs_write_inode\n\t\t\t\t\t            LOCK(ui_mutex)\n\t\t\t\t\t\t\t   \u2191\n\t      wb_wait_for_completion (Wait wb work) \u003c-- deadlock!\n\nReproducer (Detail program in [Link]):\n  1. SYS_renameat2(\"/mp/dir/file\", \"/mp/dir/whiteout\", RENAME_WHITEOUT)\n  2. Consume out of space before kernel(mdelay) doing budget for whiteout\n\nFix it by doing whiteout space budget before locking ubifs inodes.\nBTW, it also fixes wrong goto tag \u0027out_release\u0027 in whiteout budget\nerror handling path(It should at least recover dir i_size and unlock\n4 ubifs inodes)."
        }
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        "dateUpdated": "2026-05-11T13:58:14.868Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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      "references": [
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          "url": "https://git.kernel.org/stable/c/9dddc8211430fb851ddf0b168e3a00c6f66cc185"
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        {
          "url": "https://git.kernel.org/stable/c/37bdf1ad592555ecda1d55b89f6e393e4c0589d1"
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        {
          "url": "https://git.kernel.org/stable/c/83e42a78428fc354f5e2049935b84c8d8d29b787"
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          "url": "https://git.kernel.org/stable/c/c58af8564a7b08757173009030b74baf4b2b762b"
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          "url": "https://git.kernel.org/stable/c/70e9090acc32348cedc5def0cd6d5c126efc97b9"
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        {
          "url": "https://git.kernel.org/stable/c/afd427048047e8efdedab30e8888044e2be5aa9c"
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      "title": "ubifs: Fix deadlock in concurrent rename whiteout and inode writeback",
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    "cveId": "CVE-2021-47637",
    "datePublished": "2025-02-26T01:54:10.709Z",
    "dateReserved": "2025-02-26T01:48:21.519Z",
    "dateUpdated": "2026-05-11T13:58:14.868Z",
    "state": "PUBLISHED"
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    "epss": {
      "cve": "CVE-2021-47637",
      "date": "2026-09-17",
      "epss": "0.00189",
      "percentile": "0.08755"
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    "nvd": "{\"cve\":{\"id\":\"CVE-2021-47637\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-02-26T06:37:05.477\",\"lastModified\":\"2026-06-17T04:18:12.670\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nubifs: Fix deadlock in concurrent rename whiteout and inode writeback\\n\\nFollowing hung tasks:\\n[   77.028764] task:kworker/u8:4    state:D stack:    0 pid:  132\\n[   77.028820] Call Trace:\\n[   77.029027]  schedule+0x8c/0x1b0\\n[   77.029067]  mutex_lock+0x50/0x60\\n[   77.029074]  ubifs_write_inode+0x68/0x1f0 [ubifs]\\n[   77.029117]  __writeback_single_inode+0x43c/0x570\\n[   77.029128]  writeback_sb_inodes+0x259/0x740\\n[   77.029148]  wb_writeback+0x107/0x4d0\\n[   77.029163]  wb_workfn+0x162/0x7b0\\n\\n[   92.390442] task:aa              state:D stack:    0 pid: 1506\\n[   92.390448] Call Trace:\\n[   92.390458]  schedule+0x8c/0x1b0\\n[   92.390461]  wb_wait_for_completion+0x82/0xd0\\n[   92.390469]  __writeback_inodes_sb_nr+0xb2/0x110\\n[   92.390472]  writeback_inodes_sb_nr+0x14/0x20\\n[   92.390476]  ubifs_budget_space+0x705/0xdd0 [ubifs]\\n[   92.390503]  do_rename.cold+0x7f/0x187 [ubifs]\\n[   92.390549]  ubifs_rename+0x8b/0x180 [ubifs]\\n[   92.390571]  vfs_rename+0xdb2/0x1170\\n[   92.390580]  do_renameat2+0x554/0x770\\n\\n, are caused by concurrent rename whiteout and inode writeback processes:\\n\\trename_whiteout(Thread 1)\\t        wb_workfn(Thread2)\\nubifs_rename\\n  do_rename\\n    lock_4_inodes (Hold ui_mutex)\\n    ubifs_budget_space\\n      make_free_space\\n        shrink_liability\\n\\t  __writeback_inodes_sb_nr\\n\\t    bdi_split_work_to_wbs (Queue new wb work)\\n\\t\\t\\t\\t\\t      wb_do_writeback(wb work)\\n\\t\\t\\t\\t\\t\\t__writeback_single_inode\\n\\t\\t\\t\\t\\t          ubifs_write_inode\\n\\t\\t\\t\\t\\t            LOCK(ui_mutex)\\n\\t\\t\\t\\t\\t\\t\\t   \u2191\\n\\t      wb_wait_for_completion (Wait wb work) \u003c-- deadlock!\\n\\nReproducer (Detail program in [Link]):\\n  1. SYS_renameat2(\\\"/mp/dir/file\\\", \\\"/mp/dir/whiteout\\\", RENAME_WHITEOUT)\\n  2. Consume out of space before kernel(mdelay) doing budget for whiteout\\n\\nFix it by doing whiteout space budget before locking ubifs inodes.\\nBTW, it also fixes wrong goto tag \u0027out_release\u0027 in whiteout budget\\nerror handling path(It should at least recover dir i_size and unlock\\n4 ubifs inodes).\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad:\\n\\nubifs: Se corrige interbloqueo en concurrencia de un renombrado con whiteout simult\u00e1neo a la escritura del inodo.\\n\\nTareas colgadas:\\n[   77.028764] task:kworker/u8:4    state:D stack:    0 pid:  132\\n[   77.028820] Call Trace:\\n[   77.029027]  schedule+0x8c/0x1b0\\n[   77.029067]  mutex_lock+0x50/0x60\\n[   77.029074]  ubifs_write_inode+0x68/0x1f0 [ubifs]\\n[   77.029117]  __writeback_single_inode+0x43c/0x570\\n[   77.029128]  writeback_sb_inodes+0x259/0x740\\n[   77.029148]  wb_writeback+0x107/0x4d0\\n[   77.029163]  wb_workfn+0x162/0x7b0\\n\\n[   92.390442] task:aa              state:D stack:    0 pid: 1506\\n[   92.390448] Call Trace:\\n[   92.390458]  schedule+0x8c/0x1b0\\n[   92.390461]  wb_wait_for_completion+0x82/0xd0\\n[   92.390469]  __writeback_inodes_sb_nr+0xb2/0x110\\n[   92.390472]  writeback_inodes_sb_nr+0x14/0x20\\n[   92.390476]  ubifs_budget_space+0x705/0xdd0 [ubifs]\\n[   92.390503]  do_rename.cold+0x7f/0x187 [ubifs]\\n[   92.390549]  ubifs_rename+0x8b/0x180 [ubifs]\\n[   92.390571]  vfs_rename+0xdb2/0x1170\\n[   92.390580]  do_renameat2+0x554/0x770\\n\\n, ocasionado por procesos simult\u00e1neos de renombrado con whiteout y escritura del inodo:\\n\\trename_whiteout(Thread 1)\\t        wb_workfn(Thread2)\\nubifs_rename\\n  do_rename\\n    lock_4_inodes (Hold ui_mutex)\\n    ubifs_budget_space\\n      make_free_space\\n        shrink_liability\\n\\t  __writeback_inodes_sb_nr\\n\\t    bdi_split_work_to_wbs (Queue new wb work)\\n\\t\\t\\t\\t\\t      wb_do_writeback(wb work)\\n\\t\\t\\t\\t\\t\\t__writeback_single_inode\\n\\t\\t\\t\\t\\t          ubifs_write_inode\\n\\t\\t\\t\\t\\t            LOCK(ui_mutex)\\n\\t\\t\\t\\t\\t\\t\\t   ?\\n\\t      wb_wait_for_completion (Wait wb work) \u0026lt;-- \u00a1interbloqueo!\\n\\nCaso de prueba:\\n  1. SYS_renameat2(\\\"/mp/dir/file\\\", \\\"/mp/dir/whiteout\\\", RENAME_WHITEOUT)\\n  2. Consumir todo el espacio antes de que kernel(mdelay) planifique el whiteout\\n\\nArreglado calculando el espacio de whiteout antes de bloquear los inodos de ubifs.\\n\\nTambi\u00e9n soluciona etiqueta la etiqueta goto err\u00f3nea \u0027out_release\u0027 en el flujo de errores\\nde la planificaci\u00f3n del whiteout (al menos deber\u00eda recuperar el directorio i_size y desbloquear 4 inodos de ubifs).\\n\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/ubifs/dir.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"9e0a1fff8db56eaaebb74b4a3ef65f86811c4798\",\"lessThan\":\"9dddc8211430fb851ddf0b168e3a00c6f66cc185\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"9e0a1fff8db56eaaebb74b4a3ef65f86811c4798\",\"lessThan\":\"37bdf1ad592555ecda1d55b89f6e393e4c0589d1\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"9e0a1fff8db56eaaebb74b4a3ef65f86811c4798\",\"lessThan\":\"83e42a78428fc354f5e2049935b84c8d8d29b787\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"9e0a1fff8db56eaaebb74b4a3ef65f86811c4798\",\"lessThan\":\"c58af8564a7b08757173009030b74baf4b2b762b\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"9e0a1fff8db56eaaebb74b4a3ef65f86811c4798\",\"lessThan\":\"70e9090acc32348cedc5def0cd6d5c126efc97b9\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"9e0a1fff8db56eaaebb74b4a3ef65f86811c4798\",\"lessThan\":\"8b278c8dcfb565cb65eceb62a38cbf7a7c326db5\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"9e0a1fff8db56eaaebb74b4a3ef65f86811c4798\",\"lessThan\":\"afd427048047e8efdedab30e8888044e2be5aa9c\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/ubifs/dir.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"4.9\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"4.9\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"4.19.238\",\"lessThanOrEqual\":\"4.19.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.4.189\",\"lessThanOrEqual\":\"5.4.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.110\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.33\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.16.19\",\"lessThanOrEqual\":\"5.16.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.17.2\",\"lessThanOrEqual\":\"5.17.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.18\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":5.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":3.6},{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":5.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":3.6}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2025-10-01T19:50:51.071622Z\",\"id\":\"CVE-2021-47637\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-667\"}]},{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-667\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"4.9\",\"versionEndExcluding\":\"4.19.238\",\"matchCriteriaId\":\"4F595F79-E987-432C-B888-4E73F3873ECD\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"4.20\",\"versionEndExcluding\":\"5.4.189\",\"matchCriteriaId\":\"8CB6E8F5-C2B1-46F3-A807-0F6104AC340F\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"5.5\",\"versionEndExcluding\":\"5.10.110\",\"matchCriteriaId\":\"91D3BFD0-D3F3-4018-957C-96CCBF357D79\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"5.11\",\"versionEndExcluding\":\"5.15.33\",\"matchCriteriaId\":\"27C42AE8-B387-43E2-938A-E1C8B40BE6D5\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"5.16\",\"versionEndExcluding\":\"5.16.19\",\"matchCriteriaId\":\"20C43679-0439-405A-B97F-685BEE50613B\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"5.17\",\"versionEndExcluding\":\"5.17.2\",\"matchCriteriaId\":\"210C679C-CF84-44A3-8939-E629C87E54BF\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/37bdf1ad592555ecda1d55b89f6e393e4c0589d1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/70e9090acc32348cedc5def0cd6d5c126efc97b9\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/83e42a78428fc354f5e2049935b84c8d8d29b787\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/8b278c8dcfb565cb65eceb62a38cbf7a7c326db5\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/9dddc8211430fb851ddf0b168e3a00c6f66cc185\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/afd427048047e8efdedab30e8888044e2be5aa9c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/c58af8564a7b08757173009030b74baf4b2b762b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2026-06-30T10:18:16+00:00",
      "cve": "CVE-2021-47637",
      "id": "CVE-2021-47637",
      "initial_release_date": "2021-01-01T00:00:00+00:00",
      "product_status:known_affected": "14",
      "product_status:known_not_affected": "260",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ubifs: Fix deadlock in concurrent rename whiteout and inode writeback",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-47637.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-31T01:53:19Z",
      "cve": "CVE-2021-47637",
      "id": "CVE-2021-47637",
      "initial_release_date": "2025-10-25T00:43:12Z",
      "product_status:known_affected": "334",
      "product_status:known_not_affected": "358",
      "product_status:recommended": "223",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2021-47637",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2021-47637.json",
      "version": "14"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.