{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-80808", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.794Z", "datePublished": "2026-09-04T15:13:28.562Z", "dateUpdated": "2026-10-19T08:44:01.677Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:44:01.677Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: stop retrying saturated xattr cache entries\n\next4_xattr_block_set() retries when a cache entry selected for reuse\nhas a saturated reference count after taking the buffer lock. The retry\nreturns to the mbcache lookup without making that entry ineligible, so\nit can select the same unusable entry indefinitely. A task spinning\nthere can hold the parent directory's i_rwsem and leave concurrent\nrmdir callers blocked.\n\nNormally a reusable entry has a reference count below\nEXT4_XATTR_REFCOUNT_MAX because the count and MBE_REUSABLE_B are\nupdated under the same buffer lock. A corrupted filesystem can violate\nthat invariant. The syzbot reproducer reports allocator and xattr\ncorruption before triggering this retry loop.\n\nCheck the untrusted on-disk count before incrementing it, avoiding\noverflow, and clear MBE_REUSABLE_B when it is already saturated. The\nnext lookup then skips the entry that was just proven unusable. This\nmirrors the normal transition at EXT4_XATTR_REFCOUNT_MAX; the release\npath marks the entry reusable again on the exact 1024-to-1023\ntransition.\n\nUsing the same QEMU harness and guest parameters, current unpatched\nLinux hung in 6 of 8 420-second trials with the do_rmdir signature;\nrepresentative NMI backtraces caught the owner spinning in\next4_xattr_block_set(). The patched kernel completed 28 of 28 trials\nwithout a hung-task report; the final twelve trials exercised the\nreviewed overflow-safe form of the change. syzbot's patch testing also\ncompleted without reproducing the hang." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ext4/xattr.c" ], "versions": [ { "version": "1a56cd972ce121b6cf2517a47a578782bbd2ec95", "lessThan": "119a2f053242ed75bdd2ebc95baf3ae7db6ccacf", "status": "affected", "versionType": "git" }, { "version": "1be97463696c7291a3e1547614e96432b0bd3add", "lessThan": "61631352a5b405c89be579de00903b72e6888aa4", "status": "affected", "versionType": "git" }, { "version": "65f8b80053a1b2fd602daa6814e62d6fa90e5e9b", "lessThan": "8865cd664484517703df5c18a965dc3227572b87", "status": "affected", "versionType": "git" }, { "version": "65f8b80053a1b2fd602daa6814e62d6fa90e5e9b", "lessThan": "a40c45268f4358207aa9c53764fed2e05f62986a", "status": "affected", "versionType": "git" }, { "version": "65f8b80053a1b2fd602daa6814e62d6fa90e5e9b", "lessThan": "889ec86464d261f026f6c334040cfc6c58c99d58", "status": "affected", "versionType": "git" }, { "version": "65f8b80053a1b2fd602daa6814e62d6fa90e5e9b", "lessThan": "4902a5cba21aeaf91e6b29e20e0967a5f6abdcd9", "status": "affected", "versionType": "git" }, { "version": "65f8b80053a1b2fd602daa6814e62d6fa90e5e9b", "lessThan": "55ee6533c1db7f7656fa8dd19637f3f8b8c08dc5", "status": "affected", "versionType": "git" }, { "version": "65f8b80053a1b2fd602daa6814e62d6fa90e5e9b", "lessThan": "dbd4aea175ad3c46436acb251e817b4374628072", "status": "affected", "versionType": "git" }, { "version": "65f8b80053a1b2fd602daa6814e62d6fa90e5e9b", "lessThan": "54b6bd40898de7906acb2bccc9a96d1b8e6b4323", "status": "affected", "versionType": "git" }, { "version": "98953044b3cdb2cb7d82e7365b659e2ed4f4ca4d", "status": "affected", "versionType": "git" }, { "version": "af8ecc8d20e72130771cc076bce7fcf17ccda6c4", "status": "affected", "versionType": "git" }, { "version": "c6fac5cf5a5098732623bcd00a8a3eb9f5465144", "status": "affected", "versionType": "git" }, { "version": "96fa141fa295ae9428da73c56c9852053b575c04", "status": "affected", "versionType": "git" }, { "version": "5.10.163", "lessThan": "5.10.267", "status": "affected", "versionType": "semver" }, { "version": "5.15.61", "lessThan": "5.15.218", "status": "affected", "versionType": "semver" }, { "version": "4.19.270", "lessThan": "4.20", "status": "affected", "versionType": "semver" }, { "version": "5.4.229", "lessThan": "5.5", "status": "affected", "versionType": "semver" }, { "version": "5.18.18", "lessThan": "5.19", "status": "affected", "versionType": "semver" }, { "version": "5.19.2", "lessThan": "5.20", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ext4/xattr.c" ], "versions": [ { "version": "6.0", "status": "affected" }, { "version": "0", "lessThan": "6.0", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.267", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.218", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.185", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.154", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.106", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.47", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.11", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.1", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "5.10.163", "versionEndExcluding": "5.10.267" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.61", "versionEndExcluding": "5.15.218" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.1.185" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.6.154" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.12.106" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.18.47" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "7.1.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "7.2.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "7.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.229" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18.18" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/119a2f053242ed75bdd2ebc95baf3ae7db6ccacf" }, { "url": "https://git.kernel.org/stable/c/61631352a5b405c89be579de00903b72e6888aa4" }, { "url": "https://git.kernel.org/stable/c/8865cd664484517703df5c18a965dc3227572b87" }, { "url": "https://git.kernel.org/stable/c/a40c45268f4358207aa9c53764fed2e05f62986a" }, { "url": "https://git.kernel.org/stable/c/889ec86464d261f026f6c334040cfc6c58c99d58" }, { "url": "https://git.kernel.org/stable/c/4902a5cba21aeaf91e6b29e20e0967a5f6abdcd9" }, { "url": "https://git.kernel.org/stable/c/55ee6533c1db7f7656fa8dd19637f3f8b8c08dc5" }, { "url": "https://git.kernel.org/stable/c/dbd4aea175ad3c46436acb251e817b4374628072" }, { "url": "https://git.kernel.org/stable/c/54b6bd40898de7906acb2bccc9a96d1b8e6b4323" } ], "title": "ext4: stop retrying saturated xattr cache entries", "x_generator": { "engine": "bippy-1.2.0" } } } }