The patch titled
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
has been added to the -mm tree. Its filename is
mm-vmallocc-__vmalloc_area_node-avoid-32-bit-overflow.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-vmallocc-__vmalloc_area_node-avoid-32-bit-overflow.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-vmallocc-__vmalloc_area_node-avoid-32-bit-overflow.patch
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------------------------------------------------------
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: mm/vmalloc.c:__vmalloc_area_node(): avoid 32-bit overflow
With a machine with 3 TB (more than 2 TB memory). If you use vmalloc to
allocate > 2 TB memory, the array_size below will be overflowed.
The array_size is an unsigned int and can only be used to allocate less
than 2 TB memory. If you pass 2*1028*1028*1024*1024 = 2 * 2^40 in the
argument of vmalloc. The array_size will become 2*2^31 = 2^32. The 2^32
cannot be store with a 32 bit integer.
The fix is to change the type of array_size to unsigned long.
[akpm@xxxxxxxxxxxxxxxxxxxx: rework for current mainline]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=210023
Reported-by: <hsinhuiwu@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmalloc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/mm/vmalloc.c~mm-vmallocc-__vmalloc_area_node-avoid-32-bit-overflow
+++ a/mm/vmalloc.c
@@ -2461,9 +2461,11 @@ static void *__vmalloc_area_node(struct
{
const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
unsigned int nr_pages = get_vm_area_size(area) >> PAGE_SHIFT;
- unsigned int array_size = nr_pages * sizeof(struct page *), i;
+ unsigned long array_size
+ unsigned int i;
struct page **pages;
+ array_size = (unsigned long)nr_pages * sizeof(struct page *);
gfp_mask |= __GFP_NOWARN;
if (!(gfp_mask & (GFP_DMA | GFP_DMA32)))
gfp_mask |= __GFP_HIGHMEM;
_
Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are
mm.patch
mm-swap_state-skip-meaningless-swap-cache-readahead-when-ra_infowin-==-0-fix.patch
mm-vmallocc-__vmalloc_area_node-avoid-32-bit-overflow.patch
mm-vmstat-fix-proc-sys-vm-stat_refresh-generating-false-warnings-fix-2.patch
lib-test_bitmapc-add-for_each_set_clump-test-cases-checkpatch-fixes.patch
kernel-forkc-export-kernel_thread-to-modules.patch
