{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-43076", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:55.983Z", "datePublished": "2026-05-06T07:40:13.634Z", "dateUpdated": "2026-08-05T12:25:47.888Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:25:47.888Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate inline data i_size during inode read\n\nWhen reading an inode from disk, ocfs2_validate_inode_block() performs\nvarious sanity checks but does not validate the size of inline data. If\nthe filesystem is corrupted, an inode's i_size can exceed the actual\ninline data capacity (id_count).\n\nThis causes ocfs2_dir_foreach_blk_id() to iterate beyond the inline data\nbuffer, triggering a use-after-free when accessing directory entries from\nfreed memory.\n\nIn the syzbot report:\n - i_size was 1099511627576 bytes (~1TB)\n - Actual inline data capacity (id_count) is typically <256 bytes\n - A garbage rec_len (54648) caused ctx->pos to jump out of bounds\n - This triggered a UAF in ocfs2_check_dir_entry()\n\nFix by adding a validation check in ocfs2_validate_inode_block() to ensure\ninodes with inline data have i_size <= id_count. This catches the\ncorruption early during inode read and prevents all downstream code from\noperating on invalid data." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable OCFS2 inode and directory parsing is reached through a locally mounted crafted filesystem image or local directory enumeration, not by network packet processing. A loopback or local block-device image is a reasonable delivery path, so Local is higher and more appropriate than Physical.\nAC:L - The trigger is a deterministic malformed inline-data inode with i_size greater than id_count; syzbot and the fix discussion show reliable crashes without a race. The attacker controls the filesystem metadata, including the malformed size relationship.\nPR:N - Direct mounting of OCFS2 requires CAP_SYS_ADMIN and OCFS2 lacks FS_USERNS_MOUNT, so an unprivileged attacker cannot self-mount it through a user namespace. In the higher-severity crafted-image scenario, the victim/admin performs the privileged mount, so the attacker needs no pre-existing privileges.\nUI:R - Exploitation requires a victim or system component to mount the crafted OCFS2 filesystem and, depending on state, allow mount recovery or directory enumeration to run. That mount/open/enumeration action is user interaction.\nS:U - The impact is within the kernel instance processing the malicious filesystem. There is no VM, IOMMU, or separate security authority boundary crossed.\nC:H - The bug reads past the inline data buffer into freed memory in ocfs2_check_dir_entry, and readdir can process dirent fields and names from that memory. This is a kernel memory-safety issue with plausible high confidentiality impact.\nI:H - Although the observed report is a UAF read, it is a use-after-free over kernel memory during attacker-controlled metadata parsing. Per the required kernel guidance and uncertainty rule, UAF is scored as potentially enabling high integrity compromise.\nA:H - The syzbot report demonstrates a KASAN use-after-free in kernel context, and malformed metadata can repeatedly trigger invalid freed-memory access. A kernel oops or panic is a high availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ocfs2/inode.c" ], "versions": [ { "version": "23193e513d1cd69411469f028d56fd175d4a6b07", "lessThan": "d012c782abcabe68b5b9e71be58a15e9f9d83dc1", "status": "affected", "versionType": "git" }, { "version": "23193e513d1cd69411469f028d56fd175d4a6b07", "lessThan": "bcd46bc261b215b3b12c557a978299eafa02ecdd", "status": "affected", "versionType": "git" }, { "version": "23193e513d1cd69411469f028d56fd175d4a6b07", "lessThan": "131c0b573e1b467b7d553e9ff38003f1acd8f5f2", "status": "affected", "versionType": "git" }, { "version": "23193e513d1cd69411469f028d56fd175d4a6b07", "lessThan": "37f074e65f24f10f8d8df224a572e4cb9e6faf63", "status": "affected", "versionType": "git" }, { "version": "23193e513d1cd69411469f028d56fd175d4a6b07", "lessThan": "c1de19e891be3bfb3e1d0c7cf07bbb8fb3b77c1b", "status": "affected", "versionType": "git" }, { "version": "23193e513d1cd69411469f028d56fd175d4a6b07", "lessThan": "cd2d765aa7157f852999842af32148128c735d39", "status": "affected", "versionType": "git" }, { "version": "23193e513d1cd69411469f028d56fd175d4a6b07", "lessThan": "77d0295725109d77f5854ef5b58c0d06c08168cc", "status": "affected", "versionType": "git" }, { "version": "23193e513d1cd69411469f028d56fd175d4a6b07", "lessThan": "1524af3685b35feac76662cc551cbc37bd14775f", "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/ocfs2/inode.c" ], "versions": [ { "version": "2.6.24", "status": "affected" }, { "version": "0", "lessThan": "2.6.24", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.258", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.209", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.136", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.83", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.24", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.14", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "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": "2.6.24", "versionEndExcluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "6.6.136" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "6.12.83" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "6.18.24" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "6.19.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.24", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/d012c782abcabe68b5b9e71be58a15e9f9d83dc1" }, { "url": "https://git.kernel.org/stable/c/bcd46bc261b215b3b12c557a978299eafa02ecdd" }, { "url": "https://git.kernel.org/stable/c/131c0b573e1b467b7d553e9ff38003f1acd8f5f2" }, { "url": "https://git.kernel.org/stable/c/37f074e65f24f10f8d8df224a572e4cb9e6faf63" }, { "url": "https://git.kernel.org/stable/c/c1de19e891be3bfb3e1d0c7cf07bbb8fb3b77c1b" }, { "url": "https://git.kernel.org/stable/c/cd2d765aa7157f852999842af32148128c735d39" }, { "url": "https://git.kernel.org/stable/c/77d0295725109d77f5854ef5b58c0d06c08168cc" }, { "url": "https://git.kernel.org/stable/c/1524af3685b35feac76662cc551cbc37bd14775f" } ], "title": "ocfs2: validate inline data i_size during inode read", "x_generator": { "engine": "bippy-1.2.0" } } } }