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/[email protected] Fixes: 121e6f3 ("mm/vmalloc: hugepage vmalloc mappings") Signed-off-by: Eric Dumazet <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Nicholas Piggin <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
ambv · Nov 6, 2021 · 084f7e2 · 084f7e2
1 parent 34b46ef
commit 084f7e2
Showing 1 changed file with 2 additions and 1 deletion.
diff --git 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