{"cve":"CVE-2025-68262","nvd":{"published":"2025-12-16T15:15:55.697","modified":"2026-10-14T13:10:00.187","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: zstd - fix double-free in per-CPU stream cleanup\n\nThe crypto/zstd module has a double-free bug that occurs when multiple\ntfms are allocated and freed.\n\nThe issue happens because zstd_streams (per-CPU contexts) are freed in\nzstd_exit() during every tfm destruction, rather than being managed at\nthe module level.  When multiple tfms exist, each tfm exit attempts to\nfree the same shared per-CPU streams, resulting in a double-free.\n\nThis leads to a stack trace similar to:\n\n  BUG: Bad page state in process kworker/u16:1  pfn:106fd93\n  page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x106fd93\n  flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)\n  page_type: 0xffffffff()\n  raw: 0017ffffc0000000 dead000000000100 dead000000000122 0000000000000000\n  raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000\n  page dumped because: nonzero entire_mapcount\n  Modules linked in: ...\n  CPU: 3 UID: 0 PID: 2506 Comm: kworker/u16:1 Kdump: loaded Tainted: G    B\n  Hardware name: ...\n  Workqueue: btrfs-delalloc btrfs_work_helper\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0x5d/0x80\n   bad_page+0x71/0xd0\n   free_unref_page_prepare+0x24e/0x490\n   free_unref_page+0x60/0x170\n   crypto_acomp_free_streams+0x5d/0xc0\n   crypto_acomp_exit_tfm+0x23/0x50\n   crypto_destroy_tfm+0x60/0xc0\n   ...\n\nChange the lifecycle management of zstd_streams to free the streams only\nonce during module cleanup.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/48bc9da3c97c15f1ea24934bcb3b736acd30163d","https://git.kernel.org/stable/c/dc0f4509b0ed5d82bef78e058db0ac4df04d0695","https://git.kernel.org/stable/c/e983feaa79de1e46c9087fb9f02fedb0e5397ce6"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:17:07.138532058+00:00"},"epss":{"cve":"CVE-2025-68262","score":0.00184,"percentile":0.07887,"date":"2026-10-25"},"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."]}