{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-49850", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-05-01T14:05:17.230Z", "datePublished": "2025-05-01T14:10:05.167Z", "dateUpdated": "2026-05-11T19:07:57.952Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T19:07:57.952Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix deadlock in nilfs_count_free_blocks()\n\nA semaphore deadlock can occur if nilfs_get_block() detects metadata\ncorruption while locating data blocks and a superblock writeback occurs at\nthe same time:\n\ntask 1 task 2\n------ ------\n* A file operation *\nnilfs_truncate()\n nilfs_get_block()\n down_read(rwsem A) <--\n nilfs_bmap_lookup_contig()\n ... generic_shutdown_super()\n nilfs_put_super()\n * Prepare to write superblock *\n down_write(rwsem B) <--\n nilfs_cleanup_super()\n * Detect b-tree corruption * nilfs_set_log_cursor()\n nilfs_bmap_convert_error() nilfs_count_free_blocks()\n __nilfs_error() down_read(rwsem A) <--\n nilfs_set_error()\n down_write(rwsem B) <--\n\n *** DEADLOCK ***\n\nHere, nilfs_get_block() readlocks rwsem A (= NILFS_MDT(dat_inode)->mi_sem)\nand then calls nilfs_bmap_lookup_contig(), but if it fails due to metadata\ncorruption, __nilfs_error() is called from nilfs_bmap_convert_error()\ninside the lock section.\n\nSince __nilfs_error() calls nilfs_set_error() unless the filesystem is\nread-only and nilfs_set_error() attempts to writelock rwsem B (=\nnilfs->ns_sem) to write back superblock exclusively, hierarchical lock\nacquisition occurs in the order rwsem A -> rwsem B.\n\nNow, if another task starts updating the superblock, it may writelock\nrwsem B during the lock sequence above, and can deadlock trying to\nreadlock rwsem A in nilfs_count_free_blocks().\n\nHowever, there is actually no need to take rwsem A in\nnilfs_count_free_blocks() because it, within the lock section, only reads\na single integer data on a shared struct with\nnilfs_sufile_get_ncleansegs(). This has been the case after commit\naa474a220180 (\"nilfs2: add local variable to cache the number of clean\nsegments\"), that is, even before this bug was introduced.\n\nSo, this resolves the deadlock problem by just not taking the semaphore in\nnilfs_count_free_blocks()." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nilfs2/the_nilfs.c" ], "versions": [ { "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3", "lessThan": "3c89ca6d3dfa6c09c515807a7a97a521f5d5147e", "status": "affected", "versionType": "git" }, { "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3", "lessThan": "8b4506cff6630bb474bb46a2a75c31e533a756ba", "status": "affected", "versionType": "git" }, { "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3", "lessThan": "f0cc93080d4c09510b74ecba87fd778cca390bb1", "status": "affected", "versionType": "git" }, { "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3", "lessThan": "36ff974b0310771417c0be64b64aa221bd70d63d", "status": "affected", "versionType": "git" }, { "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3", "lessThan": "1d4ff73062096c21b47954d2996b4df259777bda", "status": "affected", "versionType": "git" }, { "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3", "lessThan": "abc082aac0d9b6b926038fc3adb7008306581be2", "status": "affected", "versionType": "git" }, { "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3", "lessThan": "cb029b54953420f7a2d65100f1c5107f14411bdc", "status": "affected", "versionType": "git" }, { "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3", "lessThan": "8ac932a4921a96ca52f61935dbba64ea87bbd5dc", "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/nilfs2/the_nilfs.c" ], "versions": [ { "version": "2.6.38", "status": "affected" }, { "version": "0", "lessThan": "2.6.38", "status": "unaffected", "versionType": "semver" }, { "version": "4.9.334", "lessThanOrEqual": "4.9.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.300", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.267", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.225", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.155", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.79", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.0.9", "lessThanOrEqual": "6.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1", "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": "2.6.38", "versionEndExcluding": "4.9.334" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "4.14.300" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "4.19.267" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "5.4.225" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "5.10.155" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "5.15.79" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.0.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3c89ca6d3dfa6c09c515807a7a97a521f5d5147e" }, { "url": "https://git.kernel.org/stable/c/8b4506cff6630bb474bb46a2a75c31e533a756ba" }, { "url": "https://git.kernel.org/stable/c/f0cc93080d4c09510b74ecba87fd778cca390bb1" }, { "url": "https://git.kernel.org/stable/c/36ff974b0310771417c0be64b64aa221bd70d63d" }, { "url": "https://git.kernel.org/stable/c/1d4ff73062096c21b47954d2996b4df259777bda" }, { "url": "https://git.kernel.org/stable/c/abc082aac0d9b6b926038fc3adb7008306581be2" }, { "url": "https://git.kernel.org/stable/c/cb029b54953420f7a2d65100f1c5107f14411bdc" }, { "url": "https://git.kernel.org/stable/c/8ac932a4921a96ca52f61935dbba64ea87bbd5dc" } ], "title": "nilfs2: fix deadlock in nilfs_count_free_blocks()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "problemTypes": [ { "descriptions": [ { "type": "CWE", "cweId": "CWE-667", "lang": "en", "description": "CWE-667 Improper Locking" } ] } ], "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": { "timestamp": "2025-10-01T16:11:54.441454Z", "id": "CVE-2022-49850", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-10-01T16:11:57.101Z" } } ] } }