{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-36027", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-17T13:50:33.159Z", "datePublished": "2024-05-30T15:10:17.129Z", "dateUpdated": "2026-08-05T11:31:41.392Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:31:41.392Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: zoned: do not flag ZEROOUT on non-dirty extent buffer\n\nBtrfs clears the content of an extent buffer marked as\nEXTENT_BUFFER_ZONED_ZEROOUT before the bio submission. This mechanism is\nintroduced to prevent a write hole of an extent buffer, which is once\nallocated, marked dirty, but turns out unnecessary and cleaned up within\none transaction operation.\n\nCurrently, btrfs_clear_buffer_dirty() marks the extent buffer as\nEXTENT_BUFFER_ZONED_ZEROOUT, and skips the entry function. If this call\nhappens while the buffer is under IO (with the WRITEBACK flag set,\nwithout the DIRTY flag), we can add the ZEROOUT flag and clear the\nbuffer's content just before a bio submission. As a result:\n\n1) it can lead to adding faulty delayed reference item which leads to a\n FS corrupted (EUCLEAN) error, and\n\n2) it writes out cleared tree node on disk\n\nThe former issue is previously discussed in [1]. The corruption happens\nwhen it runs a delayed reference update. So, on-disk data is safe.\n\n[1] https://lore.kernel.org/linux-btrfs/3f4f2a0ff1a6c818050434288925bdcf3cd719e5.1709124777.git.naohiro.aota@wdc.com/\n\nThe latter one can reach on-disk data. But, as that node is already\nprocessed by btrfs_clear_buffer_dirty(), that will be invalidated in the\nnext transaction commit anyway. So, the chance of hitting the corruption\nis relatively small.\n\nAnyway, we should skip flagging ZEROOUT on a non-DIRTY extent buffer, to\nkeep the content under IO intact." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable path is reached through ordinary filesystem syscalls (write, unlink, fsync) on a locally mounted btrfs, driving tree COW/free and metadata writeback. No network protocol handler is involved.\nAC:L - The attacker controls both sides of the race — metadata churn produces the btrfs_clear_buffer_dirty() calls while fsync()/dirty-metadata thresholds produce concurrent writeback — and lock_extent_buffer_for_io() drops the tree lock before bio submission, leaving the window completely unguarded; clean_log_buffer() hits it on every log commit, so it can be hammered continuously.\nPR:L - Any unprivileged local user with write access to the btrfs mount can drive tree-block frees and fsync-triggered metadata writeback; there is no capability check, root requirement, or ioctl gate anywhere on the path.\nUI:N - The attacker performs the entire sequence themselves with a self-driven write/delete/fsync workload; no other user or administrator has to take any action.\nS:U - The corruption is confined to the kernel's own filesystem metadata and the mounted volume, within a single security authority. No hypervisor, IOMMU, or sandbox boundary is crossed.\nC:N - The buffer is overwritten with zeros rather than exposed — there is no out-of-bounds read, no kernel pointer leak, and the zeroed block is written with an uncomputed checksum so a subsequent read fails verification with EIO instead of returning data.\nI:H - A zeroed tree node reaches persistent storage and faulty delayed reference items corrupt the extent tree, destroying shared btrfs metadata (including log-tree nodes holding fsync-promised data) that belongs to every file and user on the volume, not just the attacker.\nA:H - The faulty delayed ref triggers btrfs_abort_transaction(-EUCLEAN), which routes through __btrfs_handle_fs_error() to btrfs_set_sb_rdonly() and forces the filesystem read-only, while the BUG_ON sites in the backref update path can panic the kernel outright and on-disk metadata/log corruption can leave the volume unmountable." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/btrfs/extent_io.c" ], "versions": [ { "version": "aa6313e6ff2bfbf736a2739047bba355d8241584", "lessThan": "f4b994fccbb6f294c4b31a6ca0114b09f7245043", "status": "affected", "versionType": "git" }, { "version": "aa6313e6ff2bfbf736a2739047bba355d8241584", "lessThan": "68879386180c0efd5a11e800b0525a01068c9457", "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/btrfs/extent_io.c" ], "versions": [ { "version": "6.8", "status": "affected" }, { "version": "0", "lessThan": "6.8", "status": "unaffected", "versionType": "semver" }, { "version": "6.8.8", "lessThanOrEqual": "6.8.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.9", "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": "6.8", "versionEndExcluding": "6.8.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.9" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f4b994fccbb6f294c4b31a6ca0114b09f7245043" }, { "url": "https://git.kernel.org/stable/c/68879386180c0efd5a11e800b0525a01068c9457" } ], "title": "btrfs: zoned: do not flag ZEROOUT on non-dirty extent buffer", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2024-06-17T17:34:25.215751Z", "id": "CVE-2024-36027", "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": "2024-06-17T17:34:35.864Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-02T03:30:12.531Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/f4b994fccbb6f294c4b31a6ca0114b09f7245043", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/68879386180c0efd5a11e800b0525a01068c9457", "tags": [ "x_transferred" ] } ] } ] } }