CVE-2025-71110
Gravedad:
Pendiente de análisis
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
14/01/2026
Última modificación:
14/01/2026
Descripción
*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
mm/slub: reset KASAN tag in defer_free() before accessing freed memory<br />
<br />
When CONFIG_SLUB_TINY is enabled, kfree_nolock() calls kasan_slab_free()<br />
before defer_free(). On ARM64 with MTE (Memory Tagging Extension),<br />
kasan_slab_free() poisons the memory and changes the tag from the<br />
original (e.g., 0xf3) to a poison tag (0xfe).<br />
<br />
When defer_free() then tries to write to the freed object to build the<br />
deferred free list via llist_add(), the pointer still has the old tag,<br />
causing a tag mismatch and triggering a KASAN use-after-free report:<br />
<br />
BUG: KASAN: slab-use-after-free in defer_free+0x3c/0xbc mm/slub.c:6537<br />
Write at addr f3f000000854f020 by task kworker/u8:6/983<br />
Pointer tag: [f3], memory tag: [fe]<br />
<br />
Fix this by calling kasan_reset_tag() before accessing the freed memory.<br />
This is safe because defer_free() is part of the allocator itself and is<br />
expected to manipulate freed memory for bookkeeping purposes.



