From: Andrew Morton
mainline inclusion
from mainline-v5.11-rc1
commit 34fe653716b0d340bc26dd4823d2dbe00c57f849
category: bugfix
issue: #I3ZXZF
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
-----------------------------------------------
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:
Cc: Matthew Wilcox
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
Signed-off-by: Tong Tiangen
Reviewed-by: Chen Wandun
Signed-off-by: Chen Jun
Signed-off-by: Yu Changchun
---
mm/vmalloc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index c1243e0dac83..f988014288e6 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2463,9 +2463,11 @@ 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;
--
2.22.0
