From 1368edf0647ac112d8cfa6ce47257dc950c50f5c 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 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 Cc: [3.1.x+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 3231bf33287..1d8b32f0713 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1633,6 +1633,8 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, goto fail; 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