{"id":"CVE-2025-68262","summary":"crypto: zstd - fix double-free in per-CPU stream cleanup","details":"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   \u003cTASK\u003e\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.","modified":"2026-05-15T04:14:11.709289779Z","published":"2025-12-16T14:45:04.198Z","related":["openSUSE-SU-2025:15836-1","openSUSE-SU-2026:10301-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/68xxx/CVE-2025-68262.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/48bc9da3c97c15f1ea24934bcb3b736acd30163d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dc0f4509b0ed5d82bef78e058db0ac4df04d0695"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e983feaa79de1e46c9087fb9f02fedb0e5397ce6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/68xxx/CVE-2025-68262.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-68262"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.17.0"},{"fixed":"6.17.12"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"6.18.1"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-68262.json"}}],"schema_version":"1.7.5"}