{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47600","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-05-24T15:11:00.736Z","datePublished":"2024-06-19T14:54:00.981Z","dateUpdated":"2026-08-05T08:48:32.894Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T08:48:32.894Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm btree remove: fix use after free in rebalance_children()\n\nMove dm_tm_unlock() after dm_tm_dec()."}],"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 UAF is in dm-btree rebalance_children(), reached via local dm-thin metadata updates (discard → dm_thin_remove_range → dm_btree_remove/remove_leaves) or CAP_SYS_ADMIN dm-ioctl pool messages, not via network or adjacent protocols.\nAC:L - An attacker who can discard/unmap on a thin volume fully drives btree shrinkage into the single-child collapse path where unlock precedes dm_block_location(); no conditions outside attacker control are required, and UAFs are AC:L per guidance.\nPR:L - On hosts already using dm-thin/LVM thin pools, an unprivileged user with access to a thin-backed filesystem or device can issue discards (e.g. deletes under discard mounts or BLKDISCARD) that hit this path; creating the pool needs CAP_SYS_ADMIN but is a deployment precondition.\nUI:N - The attacker triggers the vulnerable remove/rebalance path themselves through their own I/O or ioctls; no separate victim action is required.\nS:U - This is a host-kernel heap use-after-free within the same OS security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - Unlocking the child block then reading dm_block_location(child) is a use-after-free on the bufio buffer; reclaim/spray of that object enables arbitrary kernel memory disclosure.\nI:H - The UAF can feed an attacker-controlled block number into dm_tm_dec(), corrupting the space map and yielding heap/metadata corruption primitives exploitable for arbitrary write and control-flow hijack.\nA:H - Any use-after-free can oops/panic the kernel (KASAN UAF or invalid access after reclaim), fully impacting availability even without successful code execution."}]}],"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":"a48f6a2bf33734ec5669ee03067dfb6c5b4818d6","status":"affected","versionType":"git"},{"version":"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4","lessThan":"66ea642af6fd4eacb5d0271a922130fcf8700424","status":"affected","versionType":"git"},{"version":"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4","lessThan":"b03abd0aa09c05099f537cb05b8460c4298f0861","status":"affected","versionType":"git"},{"version":"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4","lessThan":"293f957be5e39720778fb1851ced7f5fba6d51c3","status":"affected","versionType":"git"},{"version":"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4","lessThan":"501ecd90efdc9b2edc6c28852ecd098a4adf8f00","status":"affected","versionType":"git"},{"version":"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4","lessThan":"0e21e6cd5eebfc929ac5fa3b97ca2d4ace3cb6a3","status":"affected","versionType":"git"},{"version":"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4","lessThan":"607beb420b3fe23b948a9bf447d993521a02fbbb","status":"affected","versionType":"git"},{"version":"3241b1d3e0aaafbfcd320f4d71ade629728cc4f4","lessThan":"1b8d2789dad0005fd5e7d35dab26a8e1203fb6da","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":"4.4.296","lessThanOrEqual":"4.4.*","status":"unaffected","versionType":"semver"},{"version":"4.9.294","lessThanOrEqual":"4.9.*","status":"unaffected","versionType":"semver"},{"version":"4.14.259","lessThanOrEqual":"4.14.*","status":"unaffected","versionType":"semver"},{"version":"4.19.222","lessThanOrEqual":"4.19.*","status":"unaffected","versionType":"semver"},{"version":"5.4.168","lessThanOrEqual":"5.4.*","status":"unaffected","versionType":"semver"},{"version":"5.10.88","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.11","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"5.16","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":"4.4.296"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.2","versionEndExcluding":"4.9.294"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.2","versionEndExcluding":"4.14.259"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.2","versionEndExcluding":"4.19.222"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.2","versionEndExcluding":"5.4.168"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.2","versionEndExcluding":"5.10.88"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.2","versionEndExcluding":"5.15.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.2","versionEndExcluding":"5.16"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/a48f6a2bf33734ec5669ee03067dfb6c5b4818d6"},{"url":"https://git.kernel.org/stable/c/66ea642af6fd4eacb5d0271a922130fcf8700424"},{"url":"https://git.kernel.org/stable/c/b03abd0aa09c05099f537cb05b8460c4298f0861"},{"url":"https://git.kernel.org/stable/c/293f957be5e39720778fb1851ced7f5fba6d51c3"},{"url":"https://git.kernel.org/stable/c/501ecd90efdc9b2edc6c28852ecd098a4adf8f00"},{"url":"https://git.kernel.org/stable/c/0e21e6cd5eebfc929ac5fa3b97ca2d4ace3cb6a3"},{"url":"https://git.kernel.org/stable/c/607beb420b3fe23b948a9bf447d993521a02fbbb"},{"url":"https://git.kernel.org/stable/c/1b8d2789dad0005fd5e7d35dab26a8e1203fb6da"}],"title":"dm btree remove: fix use after free in rebalance_children()","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2024-06-20T17:58:48.172185Z","id":"CVE-2021-47600","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":"2024-06-20T18:07:48.062Z"}},{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-04T05:47:40.382Z"},"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/a48f6a2bf33734ec5669ee03067dfb6c5b4818d6","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/66ea642af6fd4eacb5d0271a922130fcf8700424","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/b03abd0aa09c05099f537cb05b8460c4298f0861","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/293f957be5e39720778fb1851ced7f5fba6d51c3","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/501ecd90efdc9b2edc6c28852ecd098a4adf8f00","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/0e21e6cd5eebfc929ac5fa3b97ca2d4ace3cb6a3","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/607beb420b3fe23b948a9bf447d993521a02fbbb","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/1b8d2789dad0005fd5e7d35dab26a8e1203fb6da","tags":["x_transferred"]}]}]}}