{"cve":"CVE-2021-47343","nvd":{"published":"2024-05-21T15:15:20.993","modified":"2026-08-04T10:16:58.677","status":"Modified","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","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-1188"],"references":["https://git.kernel.org/stable/c/4c84b3e0728ffe10d89c633694c35a02b5c477dc","https://git.kernel.org/stable/c/73f27adaa73e3057a9ec464e33c4f54d34ea5de3","https://git.kernel.org/stable/c/89bf942314b78d454db92427201421b5dec132d9","https://git.kernel.org/stable/c/8fbae4a1bdb5b889490cdee929e68540151536e5","https://git.kernel.org/stable/c/964d57d1962d7e68f0f578f05d9ae4a104d74851"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47343","score":0.0027,"percentile":0.19242,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}