Re: [PATCH] mm: vmalloc: Check for page allocation failure before vmlist insertion

[David Rientjes <rientjes@google.com>]

On Mon, 5 Dec 2011, Mel Gorman wrote:

> 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.
> 

Right, for 3.1.x.

> Reported-and-tested-by: Luciano Chavez <lnx1138@linux.vnet.ibm.com>
> Signed-off-by: Mel Gorman <mgorman@suse.de>

Acked-by: David Rientjes <rientjes@google.com>

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