{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-47343", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-21T14:28:16.979Z", "datePublished": "2024-05-21T14:35:50.293Z", "dateUpdated": "2026-08-05T08:47:20.543Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:47:20.543Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm btree remove: assign new_root only when removal succeeds\n\nremove_raw() in dm_btree_remove() may fail due to IO read error\n(e.g. read the content of origin block fails during shadowing),\nand the value of shadow_spine::root is uninitialized, but\nthe uninitialized value is still assign to new_root in the\nend of dm_btree_remove().\n\nFor dm-thin, the value of pmd->details_root or pmd->root will become\nan uninitialized value, so if trying to read details_info tree again\nout-of-bound memory may occur as showed below:\n\n general protection fault, probably for non-canonical address 0x3fdcb14c8d7520\n CPU: 4 PID: 515 Comm: dmsetup Not tainted 5.13.0-rc6\n Hardware name: QEMU Standard PC\n RIP: 0010:metadata_ll_load_ie+0x14/0x30\n Call Trace:\n sm_metadata_count_is_more_than_one+0xb9/0xe0\n dm_tm_shadow_block+0x52/0x1c0\n shadow_step+0x59/0xf0\n remove_raw+0xb2/0x170\n dm_btree_remove+0xf4/0x1c0\n dm_pool_delete_thin_device+0xc3/0x140\n pool_message+0x218/0x2b0\n target_message+0x251/0x290\n ctl_ioctl+0x1c4/0x4d0\n dm_ctl_ioctl+0xe/0x20\n __x64_sys_ioctl+0x7b/0xb0\n do_syscall_64+0x40/0xb0\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n\nFixing it by only assign new_root when removal succeeds" } ], "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 vulnerable path is reached only through local device-mapper operations—dmsetup ioctls on /dev/mapper/control (pool message → delete/create) or local block I/O/discard on a dm-thin volume that calls dm_thin_remove_range → dm_btree_remove—not via network packet processing.\nAC:L - An attacker can reliably force the first shadow_step to fail (leaving spine.root uninitialized) by exhausting metadata space so dm_sm_new_block returns -ENOSPC during discard/remove, or—on the admin path—by placing dm-flakey under the metadata device; neither depends on a race or layout outside attacker influence.\nPR:L - Although the dmsetup path requires capable(CAP_SYS_ADMIN), dm_btree_remove is also reachable from unprivileged discard/write I/O on a thin volume via dm_thin_remove_range/__remove_range with no capability check, which is the common cloud/container deployment of dm-thin.\nUI:N - The attacker issues the discard, writes that fill metadata, or dmsetup delete themselves; no separate victim action such as mounting a crafted filesystem is required.\nS:U - Corruption and the resulting oops remain inside the host kernel’s dm-thin/persistent-data authority and do not cross a VM, IOMMU, or other security boundary.\nC:H - The uninitialized new_root is later used as a metadata block number; at the time of the bug sm_ll_lookup_bitmap had no bounds check, so metadata_ll_load_ie performs an unbounded out-of-bounds read of kernel memory (as the commit’s non-canonical GPF demonstrates), which per guidance scores Confidentiality High.\nI:H - The same unbounded index path exists in metadata_ll_save_ie (OOB write), and installing attacker-influenceable stack garbage as pmd->root/details_root causes subsequent btree shadowing/updates to read and write metadata through a corrupted root—memory-corruption integrity impact High under the stated guidance.\nA:H - The documented consequence is a general protection fault / kernel oops when the corrupted root is reused (metadata_ll_load_ie GPF in the commit), which is a complete availability loss." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/md/persistent-data/dm-btree-remove.c" ], "versions": [ { "version": "3241b1d3e0aaafbfcd320f4d71ade629728cc4f4", "lessThan": "4c84b3e0728ffe10d89c633694c35a02b5c477dc", "status": "affected", "versionType": "git" }, { "version": "3241b1d3e0aaafbfcd320f4d71ade629728cc4f4", "lessThan": "c154775619186781aaf8a99333ac07437a1768d5", "status": "affected", "versionType": "git" }, { "version": "3241b1d3e0aaafbfcd320f4d71ade629728cc4f4", "lessThan": "73f27adaa73e3057a9ec464e33c4f54d34ea5de3", "status": "affected", "versionType": "git" }, { "version": "3241b1d3e0aaafbfcd320f4d71ade629728cc4f4", "lessThan": "8fbae4a1bdb5b889490cdee929e68540151536e5", "status": "affected", "versionType": "git" }, { "version": "3241b1d3e0aaafbfcd320f4d71ade629728cc4f4", "lessThan": "964d57d1962d7e68f0f578f05d9ae4a104d74851", "status": "affected", "versionType": "git" }, { "version": "3241b1d3e0aaafbfcd320f4d71ade629728cc4f4", "lessThan": "ba47e65a5de3e0e8270301a409fc63d3129fdb9e", "status": "affected", "versionType": "git" }, { "version": "3241b1d3e0aaafbfcd320f4d71ade629728cc4f4", "lessThan": "89bf942314b78d454db92427201421b5dec132d9", "status": "affected", "versionType": "git" }, { "version": "3241b1d3e0aaafbfcd320f4d71ade629728cc4f4", "lessThan": "ad365e9351ac2b450e7e79932ff6abf59342d91a", "status": "affected", "versionType": "git" }, { "version": "3241b1d3e0aaafbfcd320f4d71ade629728cc4f4", "lessThan": "b6e58b5466b2959f83034bead2e2e1395cca8aeb", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/md/persistent-data/dm-btree-remove.c" ], "versions": [ { "version": "3.2", "status": "affected" }, { "version": "0", "lessThan": "3.2", "status": "unaffected", "versionType": "semver" }, { "version": "4.4.276", "lessThanOrEqual": "4.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.9.276", "lessThanOrEqual": "4.9.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.240", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.198", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.133", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.51", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.12.18", "lessThanOrEqual": "5.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.13.3", "lessThanOrEqual": "5.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.14", "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": "3.2", "versionEndExcluding": "4.4.276" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2", "versionEndExcluding": "4.9.276" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2", "versionEndExcluding": "4.14.240" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2", "versionEndExcluding": "4.19.198" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2", "versionEndExcluding": "5.4.133" }, { "vulnerable": true, "criteria": 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"https://git.kernel.org/stable/c/964d57d1962d7e68f0f578f05d9ae4a104d74851" }, { "url": "https://git.kernel.org/stable/c/ba47e65a5de3e0e8270301a409fc63d3129fdb9e" }, { "url": "https://git.kernel.org/stable/c/89bf942314b78d454db92427201421b5dec132d9" }, { "url": "https://git.kernel.org/stable/c/ad365e9351ac2b450e7e79932ff6abf59342d91a" }, { "url": "https://git.kernel.org/stable/c/b6e58b5466b2959f83034bead2e2e1395cca8aeb" } ], "title": "dm btree remove: assign new_root only when removal succeeds", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CISA ADP Vulnrichment", "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2021-47343", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-05-23T19:04:19.383705Z" } } } ], "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": 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