{"id":"CVE-2026-23195","summary":"cgroup/dmem: avoid pool UAF","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ncgroup/dmem: avoid pool UAF\n\nAn UAF issue was observed:\n\nBUG: KASAN: slab-use-after-free in page_counter_uncharge+0x65/0x150\nWrite of size 8 at addr ffff888106715440 by task insmod/527\n\nCPU: 4 UID: 0 PID: 527 Comm: insmod    6.19.0-rc7-next-20260129+ #11\nTainted: [O]=OOT_MODULE\nCall Trace:\n\u003cTASK\u003e\ndump_stack_lvl+0x82/0xd0\nkasan_report+0xca/0x100\nkasan_check_range+0x39/0x1c0\npage_counter_uncharge+0x65/0x150\ndmem_cgroup_uncharge+0x1f/0x260\n\nAllocated by task 527:\n\nFreed by task 0:\n\nThe buggy address belongs to the object at ffff888106715400\nwhich belongs to the cache kmalloc-512 of size 512\nThe buggy address is located 64 bytes inside of\nfreed 512-byte region [ffff888106715400, ffff888106715600)\n\nThe buggy address belongs to the physical page:\n\nMemory state around the buggy address:\nffff888106715300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\nffff888106715380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n\u003effff888106715400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n\t\t\t\t     ^\nffff888106715480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\nffff888106715500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n\nThe issue occurs because a pool can still be held by a caller after its\nassociated memory region is unregistered. The current implementation frees\nthe pool even if users still hold references to it (e.g., before uncharge\noperations complete).\n\nThis patch adds a reference counter to each pool, ensuring that a pool is\nonly freed when its reference count drops to zero.","modified":"2026-08-12T03:51:34.289571286Z","published":"2026-02-14T16:27:21.621Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23195.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/99a2ef500906138ba58093b9893972a5c303c734"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d3081353acaa6a638dcf75726066ea556a2de8d5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23195.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23195"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b168ed458ddecc176f3b9a1f4bcd83d7a4541c14"},{"fixed":"d3081353acaa6a638dcf75726066ea556a2de8d5"},{"fixed":"99a2ef500906138ba58093b9893972a5c303c734"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23195.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.14.0"},{"fixed":"6.18.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23195.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}