{"id":"CVE-2025-68262","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-68262","generatedAt":"2026-10-28T09:26:14.218Z","title":"In the Linux kernel, the following vulnerability has been resolved: crypto: zstd - fix double-free in per-CPU stream cleanup The crypto/zstd module has a double-free bug that occurs when multiple tfms are allocated and freed.","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.","published":"2025-12-16T15:15:56.000Z","lastModified":"2026-10-14T13:10:00.000Z","status":"Deferred","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":null,"cwe":[],"affected":[],"epss":{"score":0.00184,"percentile":0.07885,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"unknown","text":"Not yet scored. NVD analysis is pending; check back once CVSS and EPSS values are published."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/48bc9da3c97c15f1ea24934bcb3b736acd30163d","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dc0f4509b0ed5d82bef78e058db0ac4df04d0695","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e983feaa79de1e46c9087fb9f02fedb0e5397ce6","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-68262","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."}