{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-47637", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-02-26T01:48:21.519Z", "datePublished": "2025-02-26T01:54:10.709Z", "dateUpdated": "2026-05-11T13:58:14.868Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T13:58:14.868Z" }, "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 ↑\n\t wb_wait_for_completion (Wait wb work) <-- 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 'out_release' in whiteout budget\nerror handling path(It should at least recover dir i_size and unlock\n4 ubifs inodes)." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ubifs/dir.c" ], "versions": [ { "version": "9e0a1fff8db56eaaebb74b4a3ef65f86811c4798", "lessThan": "9dddc8211430fb851ddf0b168e3a00c6f66cc185", "status": "affected", "versionType": "git" }, { "version": "9e0a1fff8db56eaaebb74b4a3ef65f86811c4798", "lessThan": "37bdf1ad592555ecda1d55b89f6e393e4c0589d1", "status": "affected", "versionType": "git" }, { "version": "9e0a1fff8db56eaaebb74b4a3ef65f86811c4798", "lessThan": "83e42a78428fc354f5e2049935b84c8d8d29b787", "status": "affected", "versionType": "git" }, { "version": "9e0a1fff8db56eaaebb74b4a3ef65f86811c4798", "lessThan": "c58af8564a7b08757173009030b74baf4b2b762b", "status": "affected", "versionType": "git" }, { "version": "9e0a1fff8db56eaaebb74b4a3ef65f86811c4798", "lessThan": "70e9090acc32348cedc5def0cd6d5c126efc97b9", "status": "affected", "versionType": "git" }, { "version": "9e0a1fff8db56eaaebb74b4a3ef65f86811c4798", "lessThan": "8b278c8dcfb565cb65eceb62a38cbf7a7c326db5", "status": "affected", "versionType": "git" }, { "version": "9e0a1fff8db56eaaebb74b4a3ef65f86811c4798", "lessThan": "afd427048047e8efdedab30e8888044e2be5aa9c", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ubifs/dir.c" ], "versions": [ { "version": "4.9", "status": "affected" }, { "version": "0", "lessThan": "4.9", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.238", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.189", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.110", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.33", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.16.19", "lessThanOrEqual": "5.16.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.17.2", "lessThanOrEqual": "5.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.18", "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": "4.9", "versionEndExcluding": "4.19.238" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.4.189" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.10.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.15.33" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.16.19" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.17.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.18" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9dddc8211430fb851ddf0b168e3a00c6f66cc185" }, { "url": "https://git.kernel.org/stable/c/37bdf1ad592555ecda1d55b89f6e393e4c0589d1" }, { "url": "https://git.kernel.org/stable/c/83e42a78428fc354f5e2049935b84c8d8d29b787" }, { "url": "https://git.kernel.org/stable/c/c58af8564a7b08757173009030b74baf4b2b762b" }, { "url": "https://git.kernel.org/stable/c/70e9090acc32348cedc5def0cd6d5c126efc97b9" }, { "url": "https://git.kernel.org/stable/c/8b278c8dcfb565cb65eceb62a38cbf7a7c326db5" }, { "url": "https://git.kernel.org/stable/c/afd427048047e8efdedab30e8888044e2be5aa9c" } ], "title": "ubifs: Fix deadlock in concurrent rename whiteout and inode writeback", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2021-47637", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2025-10-01T19:50:51.071622Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-667", "description": "CWE-667 Improper Locking" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-10-01T19:57:08.665Z" } } ] } }