Re: [PATCH] mm/slub: initialize the free pointer of the bootstrap kmem_cache_node

[Harry Yoo (Meta)]

On Sat, 10 Oct 2026 22:39:06 +0200, Karl Mehltretter wrote:
> With slub_debug=FZPU, validating kmem_cache_node reports
> 
>   BUG kmem_cache_node (Not tainted): Freepointer corrupt
>   Object 0xffff888000140040 @offset=64 fp=0x5a5a5a5a5a5a5a5a
> 
> and taints the kernel. Poisoning places the bootstrap object's free
> pointer outside the object, where check_object() checks it even while
> allocated.
> 
> [...]

Applied to mm/slab.git slab/for-next, thanks!

[1/1] mm/slub: initialize the free pointer of the bootstrap kmem_cache_node
      commit: 10a5ff7555ae3042393d8a662a25dca9b38ea415

Note: I did not add Cc: stable because it only affects slab_debug users
and requires writing to 'validate' field, which requires the root.

-- 
Cheers,
Harry / Hyeonggon