mm: add vmalloc check return patch.

Herton notes:

-------
   > commit f5252e009d5b87071a919221e4f6624184005368 upstream.
   >
   > The /proc/vmallocinfo shows information about vmalloc allocations in
   > vmlist that is a linklist of vm_struct.  It, however, may access pages
   > field of vm_struct where a page was not allocated.  This results in a null
   > pointer access and leads to a kernel panic.
   >
   > Why this happens: In __vmalloc_node_range() called from vmalloc(), newly
   > allocated vm_struct is added to vmlist at __get_vm_area_node() and then,
   > some fields of vm_struct such as nr_pages and pages are set at
   > __vmalloc_area_node().  In other words, it is added to vmlist before it is
   > fully initialized.  At the same time, when the /proc/vmallocinfo is read,
   > it accesses the pages field of vm_struct according to the nr_pages field
   > at show_numa_info().  Thus, a null pointer access happens.
   >
   > The patch adds the newly allocated vm_struct to the vmlist *after* it is
   > fully initialized.  So, it can avoid accessing the pages field with
   > unallocated page when show_numa_info() is called.
   >
   > Signed-off-by: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
   > Cc: Andrew Morton <akpm@linux-foundation.org>
   > Cc: David Rientjes <rientjes@google.com>
   > Cc: Namhyung Kim <namhyung@gmail.com>
   > Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
   > Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
   > Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
   > Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
   > [PG: .34 has VMALLOC_START/END vs. start/end in f5252e009d5]
   > Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
   [...]

   commit 1368edf0647ac112d8cfa6ce47257dc950c50f5c ("mm: vmalloc: check for
   page allocation failure before vmlist insertion") addresses a regression
   on this change, something to consider for inclusion in this stable
   update as well.
-------

Reported-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

2 files changed, 50 insertions, 0 deletions

diff --git a/queue/mm-vmalloc-check-for-page-allocation-failure-before-.patch b/queue/mm-vmalloc-check-for-page-allocation-failure-before-.patch
new file mode 100644
index 0000000..567647d
--- /dev/null
+++ b/queue/mm-vmalloc-check-for-page-allocation-failure-before-.patch
@@ -0,0 +1,49 @@
+From b977fc06307a5290bf5251a5768beb4b5210945d Mon Sep 17 00:00:00 2001
+From: Mel Gorman <mgorman@suse.de>
+Date: Thu, 8 Dec 2011 14:34:30 -0800
+Subject: [PATCH] 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 <mgorman@suse.de>
+Reported-by: Luciano Chavez <lnx1138@linux.vnet.ibm.com>
+Tested-by: Luciano Chavez <lnx1138@linux.vnet.ibm.com>
+Reviewed-by: Rik van Riel <riel@redhat.com>
+Acked-by: David Rientjes <rientjes@google.com>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
+
+diff --git a/mm/vmalloc.c b/mm/vmalloc.c
+index 3843789..edece35 100644
+--- a/mm/vmalloc.c
++++ b/mm/vmalloc.c
+@@ -1601,6 +1601,8 @@ static void *__vmalloc_node(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
+-- 
+1.7.12.rc2
+
diff --git a/queue/series b/queue/series
index f535b65..3eeab94 100644
--- a/queue/series
+++ b/queue/series
@@ -139,6 +139,7 @@ media-Remove-the-old-V4L1-v4lgrab.c-file.patch
 drm-i915-Sanity-check-pread-pwrite.patch
 drm-i915-Rephrase-pwrite-bounds-checking-to-avoid-an.patch
 mm-avoid-null-pointer-access-in-vm_struct-via-proc-v.patch
+mm-vmalloc-check-for-page-allocation-failure-before-.patch
 kbuild-Fix-passing-Wno-options-to-gcc-4.4.patch
 USB-serial-pl2303-rm-duplicate-id.patch
 USB-Fix-Corruption-issue-in-USB-ftdi-driver-ftdi_sio.patch