{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-63812", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.013Z", "datePublished": "2026-07-19T12:02:13.606Z", "dateUpdated": "2026-08-17T04:51:19.062Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:51:19.062Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix incorrect FI_NO_EXTENT handling in __destroy_extent_node()\n\nWhen __destroy_extent_node() sets the inode flag FI_NO_EXTENT, it does\nnot reset the length of the largest extent to 0 and update the inode\nfolio. Since modifications to the extent tree are disallowed afterward,\nthe cached largest extent may become stale. This can trigger the\nfollowing error in xfstests generic/388:\n\nF2FS-fs (dm-0): sanity_check_extent_cache: inode (ino=1761) extent info [220057, 57, 6] is incorrect, run fsck to fix\n\nIn the f2fs_drop_inode path, __destroy_extent_node() does not need to\nguarantee that et->node_cnt is 0, because concurrency with writeback\nis expected in this path, and writeback may update the extent cache.\n\nThis patch reverts commit ed78aeebef05 (\"f2fs: fix node_cnt race between\nextent node destroy and writeback\"), and remove the unnecessary zero\ncheck of et->node_cnt." } ], "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 reached only through local VFS filesystem activity (write, unlink, concurrent writeback) on an F2FS mount, most severely on Android/embedded userdata partitions where F2FS is the default local filesystem.\nAC:L - An attacker can reliably orchestrate the inode-eviction/writeback race by unlinking files while writeback is in progress on the same inode, controlling both sides of the concurrency window.\nPR:L - Triggering the race requires only unprivileged write access to files on a mounted F2FS filesystem (e.g., creating, writing, and unlinking files in one's own directory on Android /data), not real root or CAP_SYS_ADMIN.\nUI:N - Exploitation requires no action from a separate victim; the attacker drives the file I/O and unlink operations that provoke the stale extent-cache state.\nS:U - Impact is confined to kernel/filesystem integrity on the affected host; there is no cross-security-authority boundary such as VM escape or container-to-host breakout.\nC:H - Stale largest-extent metadata persisted to the on-disk inode can cause subsequent reads (after inode reload or inode-number reuse) to map logical file offsets to wrong physical blocks, disclosing data from other files or freed blocks.\nI:H - Incorrect on-disk extent metadata corrupts the inode-to-block mapping and can cause wrong data blocks to be associated with a file, constituting exploitable filesystem metadata corruption with integrity impact beyond a simple crash.\nA:H - The stale cache triggers sanity_check_extent_cache failures (as seen in xfstests generic/388), f2fs_handle_error(ERROR_CORRUPTED_INODE), and potential kernel BUG_ON via f2fs_bug_on when CONFIG_F2FS_CHECK_FS is enabled, all causing denial of filesystem or kernel service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/f2fs/extent_cache.c" ], "versions": [ { "version": "42dd1c91f993431d0b399502479d00e6ad1bca71", "lessThan": "7e4d8f98be63f98856a5176b9188dada6e7ba9ee", "status": "affected", "versionType": "git" }, { "version": "ab1eaf9d5c99042f5b0243bf67a06283a4c0757f", "lessThan": "58a5deb220bcac4c73bf58954c0845644c997487", "status": "affected", "versionType": "git" }, { "version": "b0e4395870eb3441ddc959f6710b5f6ca61aff26", "lessThan": "20190e498057997532c7f186d081011f18e0a462", "status": "affected", "versionType": "git" }, { "version": "ed78aeebef05212ef7dca93bd931e4eff67c113f", "lessThan": "edf12cbeeeabe799bd2ee21fdb5c336cce6fbad7", "status": "affected", "versionType": "git" }, { "version": "ed78aeebef05212ef7dca93bd931e4eff67c113f", "lessThan": "1f70ddb28a3c71df124da5fa4040c808116d6bb9", "status": "affected", "versionType": "git" }, { "version": "0559a0e962aacbb47519e26ee663be04b72dcb92", "status": "affected", "versionType": "git" }, { "version": "6.6.140", "lessThan": "6.6.144", "status": "affected", "versionType": "semver" }, { "version": "6.12.88", "lessThan": "6.12.95", "status": "affected", "versionType": "semver" }, { "version": "6.18.30", "lessThan": "6.18.38", "status": "affected", "versionType": "semver" }, { "version": "7.0.7", "lessThan": "7.1", "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/f2fs/extent_cache.c" ], "versions": [ { "version": "7.1", "status": "affected" }, { "version": "0", "lessThan": "7.1", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.144", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.95", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.38", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.3", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.6.140", "versionEndExcluding": "6.6.144" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.88", "versionEndExcluding": "6.12.95" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.30", "versionEndExcluding": "6.18.38" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.1.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0.7" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/7e4d8f98be63f98856a5176b9188dada6e7ba9ee" }, { "url": "https://git.kernel.org/stable/c/58a5deb220bcac4c73bf58954c0845644c997487" }, { "url": "https://git.kernel.org/stable/c/20190e498057997532c7f186d081011f18e0a462" }, { "url": "https://git.kernel.org/stable/c/edf12cbeeeabe799bd2ee21fdb5c336cce6fbad7" }, { "url": "https://git.kernel.org/stable/c/1f70ddb28a3c71df124da5fa4040c808116d6bb9" } ], "title": "f2fs: fix incorrect FI_NO_EXTENT handling in __destroy_extent_node()", "x_generator": { "engine": "bippy-1.2.0" } } } }