diff options
| author | Andrew Morton <akpm@linux-foundation.org> | 2020-12-14 19:08:43 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-15 12:13:41 -0800 |
| commit | 34fe653716b0d340bc26dd4823d2dbe00c57f849 (patch) | |
| tree | 53402bb0e2d5d266b9e1e76ef37133aa04c991e0 /mm/vmalloc.c | |
| parent | d5037d1d82b39d70e2f5952528f24172f33f5629 (diff) | |
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@linux-foundation.org: rework for current mainline]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=210023
Reported-by: <hsinhuiwu@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmalloc.c')
| -rw-r--r-- | mm/vmalloc.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 6ae491a8b210..8a2dc571bc8d 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2461,9 +2461,11 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, { 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; |