From 40702f168a9edf8eeb47c63adf7bc2eaede6bfbe Mon Sep 17 00:00:00 2001 From: "Mike Rapoport (Microsoft)" Date: Thu, 3 Sep 2026 12:28:28 +0300 Subject: [PATCH] mm/vmalloc: set area's page_order after allocation succeeds __vmalloc_area_node() calls set_vm_area_page_order() to set area's page_order before actually allocating pages to populate the area. If allocation of large pages in HUGE_VMAP case fails midway, this leaves the area with elevated page_order throughout the cleanup path. There is no actual issue with this because the only place that currently relies on area->page_order on the cleanup path is the loop calculating the direct map alias range in vm_reset_perms() and it anyway skips unpopulated pages. But having set_vm_area_page_order() in the middle of __vmalloc_area_node() makes things very obscure, hard to reason about and error prone against future changes of the cleanup path. Move the call to set_vm_area_page_order() just before the successful return from __vmalloc_area_node() where page order is guaranteed. While on it, initialize local page_order variable with its declaration. Link: https://lore.kernel.org/20260903-execmem-set-vm-perms-v0-2-v3-2-949b64a9f755@kernel.org Signed-off-by: Mike Rapoport (Microsoft) Signed-off-by: Andrew Morton Reviewed-by: Uladzislau Rezki (Sony) Reviewed-by: Dev Jain Cc: Albert Ou Cc: Alexander Gordeev Cc: Alexandre Ghiti Cc: Andy Lutomirski Cc: "Borislav Petkov (AMD)" Cc: Brendan Jackman Cc: Catalin Marinas Cc: Christian Borntraeger Cc: Dave Hansen Cc: David Hildenbrand Cc: Gerald Schaefer Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: Ingo Molnar Cc: Len Brown Cc: Palmer Dabbelt Cc: Peter Zijlstra Cc: "Rafael J. Wysocki" Cc: Ryan Roberts Cc: Sven Schnelle Cc: Vasily Gorbik Cc: WANG Xuerui Cc: Will Deacon Cc: Kevin Brodsky --- mm/vmalloc.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 22566e0b6e38..9bd94e2f2895 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3873,7 +3873,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, unsigned long size = get_vm_area_size(area); unsigned long array_size; unsigned long nr_small_pages = size >> PAGE_SHIFT; - unsigned int page_order; + unsigned int page_order = page_shift - PAGE_SHIFT; unsigned int flags; int ret; @@ -3901,9 +3901,6 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, goto fail; } - set_vm_area_page_order(area, page_shift - PAGE_SHIFT); - page_order = vm_area_page_order(area); - /* * High-order nofail allocations are really expensive and * potentially dangerous (pre-mature OOM, disruptive reclaim @@ -3958,6 +3955,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, goto fail; } + set_vm_area_page_order(area, page_order); return area->addr; fail: