From: Shivam Kalra Date: Tue, 19 May 2026 12:12:15 +0000 (+0530) Subject: mm/vmalloc: use physical page count for vrealloc() grow-in-place check X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d57ac904ffdce6c06e9a113fce603420c041b48c;p=thirdparty%2Flinux.git mm/vmalloc: use physical page count for vrealloc() grow-in-place check Update the grow-in-place check in vrealloc() to compare the requested size against the actual physical page count (vm->nr_pages) rather than the virtual area size (alloced_size, derived from get_vm_area_size()). Currently both values are equivalent, but the upcoming vrealloc() shrink functionality will free pages without reducing the virtual reservation size. After such a shrink, the old alloced_size-based comparison would incorrectly allow a grow-in-place operation to succeed and attempt to access freed pages. Switch to vm->nr_pages now so the check remains correct once shrink support is added. Link: https://lore.kernel.org/20260519-vmalloc-shrink-v14-2-70b96ee3e9c9@zohomail.in Signed-off-by: Shivam Kalra Reviewed-by: Uladzislau Rezki (Sony) Cc: Alice Ryhl Cc: Danilo Krummrich Signed-off-by: Andrew Morton --- diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 5555601b9529..3e159b74cfab 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -4343,6 +4343,12 @@ void *vrealloc_node_align_noprof(const void *p, size_t size, unsigned long align if (unlikely(flags & __GFP_THISNODE) && nid != NUMA_NO_NODE && nid != page_to_nid(vmalloc_to_page(p))) goto need_realloc; + } else { + /* + * If p is NULL, vrealloc behaves exactly like vmalloc. + * Skip the shrink and in-place grow paths. + */ + goto need_realloc; } /* @@ -4361,7 +4367,7 @@ void *vrealloc_node_align_noprof(const void *p, size_t size, unsigned long align /* * We already have the bytes available in the allocation; use them. */ - if (size <= alloced_size) { + if (size <= vm->nr_pages << PAGE_SHIFT) { /* * No need to zero memory here, as unused memory will have * already been zeroed at initial allocation time or during