[Ocfs2-devel] [PATCH 2/7] buffer: Promote to unsigned long long before shifting

Matthew Wilcox (Oracle) willy at infradead.org
Sun Oct 4 11:04:23 PDT 2020


On 32-bit systems, this shift will overflow for files larger than 4GB.

Cc: stable at vger.kernel.org
Fixes: 5417169026c3 ("[FS] Implement block_page_mkwrite.")
Signed-off-by: Matthew Wilcox (Oracle) <willy at infradead.org>
---
 fs/buffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index 50bbc99e3d96..66f4765e60ee 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2515,7 +2515,7 @@ int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
 	}
 
 	/* page is wholly or partially inside EOF */
-	if (((page->index + 1) << PAGE_SHIFT) > size)
+	if (((page->index + 1ULL) << PAGE_SHIFT) > size)
 		end = size & ~PAGE_MASK;
 	else
 		end = PAGE_SIZE;
-- 
2.28.0




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