{"id":"CVE-2026-93216","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_owner: use memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()\n\nprint_page_owner_memcg() reads page->memcg_data via READ_ONCE() at the\nstart to guar…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_owner: use memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()\n\nprint_page_owner_memcg() reads page->memcg_data via READ_ONCE() at the\nstart to guar…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= fcf8935832b86d3437f00e732c6d0d4d2819d6a9 < 46761406e14381dc35f498c247a87565b87ea2ef","Linux >= fcf8935832b86d3437f00e732c6d0d4d2819d6a9 < 90f095b816e25c6a9e4446d299bac5007fdcb3df","Linux 5.18"],"published":"2026-09-24","updated":"2026-09-24","sourceUpdated":"2026-09-24T16:17:16.670","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-93216","references":[{"url":"https://git.kernel.org/stable/c/46761406e14381dc35f498c247a87565b87ea2ef","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/90f095b816e25c6a9e4446d299bac5007fdcb3df","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-24T15:45:56.670Z","slug":"CVE-2026-93216","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_owner: use memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()\n\nprint_page_owner_memcg() reads page->memcg_data via READ_ONCE() at the\nstart to guard against tail pages and NULL data.  However, it later\nre-reads page->memcg_data locklessly in two places:\n\n1: page_memcg_check(page)\n\n2: PageMemcgKmem(page) (via folio_memcg_kmem(), which includes\n   VM_BUG_ON assertions for tail pages and MEMCG_DATA_OBJEXTS)\n\nIf the page is concurrently freed and reallocated as a THP tail page or\nslab page between these calls, the VM_BUG_ON assertions can trigger on\nCONFIG_DEBUG_VM=y builds, crashing the kernel.\n\nFix both TOCTOU issues by using the memcg_data snapshot throughout.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}