Commit 1368edf0 authored by Mel Gorman's avatar Mel Gorman Committed by Linus Torvalds

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: default avatarMel Gorman <mgorman@suse.de>
Reported-by: default avatarLuciano Chavez <lnx1138@linux.vnet.ibm.com>
Tested-by: default avatarLuciano Chavez <lnx1138@linux.vnet.ibm.com>
Reviewed-by: default avatarRik van Riel <riel@redhat.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>		[3.1.x+]
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d0215638
......@@ -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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