{"id":"CVE-2025-71110","summary":"mm/slub: reset KASAN tag in defer_free() before accessing freed memory","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/slub: reset KASAN tag in defer_free() before accessing freed memory\n\nWhen CONFIG_SLUB_TINY is enabled, kfree_nolock() calls kasan_slab_free()\nbefore defer_free(). On ARM64 with MTE (Memory Tagging Extension),\nkasan_slab_free() poisons the memory and changes the tag from the\noriginal (e.g., 0xf3) to a poison tag (0xfe).\n\nWhen defer_free() then tries to write to the freed object to build the\ndeferred free list via llist_add(), the pointer still has the old tag,\ncausing a tag mismatch and triggering a KASAN use-after-free report:\n\n  BUG: KASAN: slab-use-after-free in defer_free+0x3c/0xbc mm/slub.c:6537\n  Write at addr f3f000000854f020 by task kworker/u8:6/983\n  Pointer tag: [f3], memory tag: [fe]\n\nFix this by calling kasan_reset_tag() before accessing the freed memory.\nThis is safe because defer_free() is part of the allocator itself and is\nexpected to manipulate freed memory for bookkeeping purposes.","modified":"2026-04-02T13:04:49.284292Z","published":"2026-01-14T15:05:57.952Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/71xxx/CVE-2025-71110.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/53ca00a19d345197a37a1bf552e8d1e7b091666c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/65d4e5af2a2e82f4fc50d8259aee208fbc6b2c1d"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/71xxx/CVE-2025-71110.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-71110"},{"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":"af92793e52c3a99b828ed4bdd277fd3e11c18d08"},{"fixed":"65d4e5af2a2e82f4fc50d8259aee208fbc6b2c1d"},{"fixed":"53ca00a19d345197a37a1bf552e8d1e7b091666c"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-71110.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"6.18.3"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-71110.json"}}],"schema_version":"1.7.5"}