| Message ID | 20241126005206.3457974-1-andrii@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [mm/stable] mm: fix vrealloc()'s KASAN poisoning logic | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 7ed39d104201..f009b21705c1 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -4093,7 +4093,8 @@ void *vrealloc_noprof(const void *p, size_t size, gfp_t flags) /* Zero out spare memory. */ if (want_init_on_alloc(flags)) memset((void *)p + size, 0, old_size - size); - + kasan_poison_vmalloc(p + size, old_size - size); + kasan_unpoison_vmalloc(p, size, KASAN_VMALLOC_PROT_NORMAL); return (void *)p; }
When vrealloc() reuses already allocated vmap_area, we need to re-annotate poisoned and unpoisoned portions of underlying memory according to the new size. Note, hard-coding KASAN_VMALLOC_PROT_NORMAL might not be exactly correct, but KASAN flag logic is pretty involved and spread out throughout __vmalloc_node_range_noprof(), so I'm using the bare minimum flag here and leaving the rest to mm people to refactor this logic and reuse it here. Fixes: 3ddc2fefe6f3 ("mm: vmalloc: implement vrealloc()") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> --- mm/vmalloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)