From 084f7e2377e89ccbc8375b5486c6b4c16682f602 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 5 Nov 2021 13:39:59 -0700 Subject: mm/large system hash: avoid possible NULL deref in alloc_large_system_hash If __vmalloc() returned NULL, is_vm_area_hugepages(NULL) will fault if CONFIG_HAVE_ARCH_HUGE_VMALLOC=y Link: https://lkml.kernel.org/r/20210915212530.2321545-1-eric.dumazet@gmail.com Fixes: 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings") Signed-off-by: Eric Dumazet Reviewed-by: Andrew Morton Cc: Nicholas Piggin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 23d3339ac4e8..133dad9f4669 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8762,7 +8762,8 @@ void *__init alloc_large_system_hash(const char *tablename, } else if (get_order(size) >= MAX_ORDER || hashdist) { table = __vmalloc(size, gfp_flags); virt = true; - huge = is_vm_area_hugepages(table); + if (table) + huge = is_vm_area_hugepages(table); } else { /* * If bucketsize is not a power-of-two, we may free -- cgit v1.2.3