{"id":"CVE-2021-47343","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-47343","generatedAt":"2026-10-27T21:48:23.440Z","title":"In the Linux kernel, the following vulnerability has been resolved: dm btree remove: assign new_root only when removal succeeds remove_raw() in dm_btree_remove() may fail due to IO read error (e.g. read the content of origin block fails during…","description":"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","published":"2024-05-21T15:15:21.000Z","lastModified":"2026-08-04T10:16:59.000Z","status":"Modified","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-1188"],"affected":["linux/linux kernel"],"epss":{"score":0.0027,"percentile":0.19024,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.27%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/4c84b3e0728ffe10d89c633694c35a02b5c477dc","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/73f27adaa73e3057a9ec464e33c4f54d34ea5de3","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/89bf942314b78d454db92427201421b5dec132d9","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8fbae4a1bdb5b889490cdee929e68540151536e5","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/964d57d1962d7e68f0f578f05d9ae4a104d74851","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ad365e9351ac2b450e7e79932ff6abf59342d91a","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b6e58b5466b2959f83034bead2e2e1395cca8aeb","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ba47e65a5de3e0e8270301a409fc63d3129fdb9e","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c154775619186781aaf8a99333ac07437a1768d5","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4c84b3e0728ffe10d89c633694c35a02b5c477dc","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/73f27adaa73e3057a9ec464e33c4f54d34ea5de3","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/89bf942314b78d454db92427201421b5dec132d9","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/8fbae4a1bdb5b889490cdee929e68540151536e5","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/964d57d1962d7e68f0f578f05d9ae4a104d74851","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/ad365e9351ac2b450e7e79932ff6abf59342d91a","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/b6e58b5466b2959f83034bead2e2e1395cca8aeb","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/ba47e65a5de3e0e8270301a409fc63d3129fdb9e","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/c154775619186781aaf8a99333ac07437a1768d5","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-47343","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}