Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: mm/slub: reset KASAN tag in defer_free() before accessing freed memory When CONFIG_SLUB_TINY is enabled, kfree_nolock() calls kasan_slab_free() before defer_free(). On ARM64 with MTE (Memory Tagging Extension), kasan_slab_free() poisons the memory and changes the tag from the original (e.g., 0xf3) to a poison tag (0xfe). When defer_free() then tries to write to the freed object to build the deferred free list via llist_add(), the pointer still has the old tag, causing a tag mismatch and triggering a KASAN use-after-free report: BUG: KASAN: slab-use-after-free in defer_free+0x3c/0xbc mm/slub.c:6537 Write at addr f3f000000854f020 by task kworker/u8:6/983 Pointer tag: [f3], memory tag: [fe] Fix this by calling kasan_reset_tag() before accessing the freed memory. This is safe because defer_free() is part of the allocator itself and is expected to manipulate freed memory for bookkeeping purposes.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected af92793e52c3a99b828ed4bdd277fd3e11c18d08 before 65d4e5af2a2e82f4fc50d8259aee208fbc6b2c1d; affected af92793e52c3a99b828ed4bdd277fd3e11c18d08 before 53ca00a19d345197a37a1bf552e8d1e7b091666c |
| Linux / Linux | affected 6.18; unaffected 0 before 6.18; unaffected 6.18.3 through 6.18.*; unaffected 6.19 through * |
CWE
No CWE identifiers supplied.