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* [PATCH] mm: vmalloc: Check for page allocation failure before vmlist insertion
@ 2011-12-05 14:07 ` Mel Gorman
  0 siblings, 0 replies; 6+ messages in thread
From: Mel Gorman @ 2011-12-05 14:07 UTC (permalink / raw)
  To: Andrew Morton
  Cc: David Rientjes, Namhyung Kim, Luciano Chavez, Linux-MM, LKML

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.

If accepted, this should be considered a -stable candidate.

Reported-and-tested-by: Luciano Chavez <lnx1138@linux.vnet.ibm.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
 mm/vmalloc.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 3231bf3..1d8b32f 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

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^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2011-12-06 20:26 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-12-05 14:07 [PATCH] mm: vmalloc: Check for page allocation failure before vmlist insertion Mel Gorman
2011-12-05 14:07 ` Mel Gorman
2011-12-06  6:56 ` Rik van Riel
2011-12-06  6:56   ` Rik van Riel
2011-12-06 20:26 ` David Rientjes
2011-12-06 20:26   ` David Rientjes

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