From 7e9062c8c8172253a86b3db01e52f8e576306a95 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 8 Dec 2011 14:34:30 -0800 Subject: mm: vmalloc: check for page allocation failure before vmlist insertion commit 1368edf0647ac112d8cfa6ce47257dc950c50f5c upstream. Commit f5252e00 ("mm: avoid null pointer access in vm_struct via /proc/vmallocinfo") adds newly allocated vm_structs to the vmlist after it is fully initialised. Unfortunately, it did not check that __vmalloc_area_node() successfully populated the area. In the event of allocation failure, the vmalloc area is freed but the pointer to freed memory is inserted into the vmlist leading to a a crash later in get_vmalloc_info(). This patch adds a check for ____vmalloc_area_node() failure within __vmalloc_node_range. It does not use "goto fail" as in the previous error path as a warning was already displayed by __vmalloc_area_node() before it called vfree in its failure path. Credit goes to Luciano Chavez for doing all the real work of identifying exactly where the problem was. Signed-off-by: Mel Gorman Reported-by: Luciano Chavez Tested-by: Luciano Chavez Reviewed-by: Rik van Riel Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/vmalloc.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'mm') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 56faf3163ee2..3a65d6f74226 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1634,6 +1634,8 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, return NULL; addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller); + if (!addr) + return NULL; /* * In this function, newly allocated vm_struct is not added -- cgit v1.2.3