filemap: avoid truncating 64-bit offset to 32 bits

marcone · pelwell · commit 44cb7813dcf3 · 2025-01-06T14:23:37.000Z
on 32-bit kernels, folio_seek_hole_data() was inadvertently truncating a
64-bit value to 32 bits, leading to a possible infinite loop when writing
to an xfs filesystem.

Signed-off-by: Marco Nelissen &lt;marco.nelissen@gmail.com&gt;
diff --git a/mm/filemap.c b/mm/filemap.c
@@ -3004,7 +3004,7 @@ static inline loff_t folio_seek_hole_data(struct xa_state *xas,
 		if (ops->is_partially_uptodate(folio, offset, bsz) ==
 							seek_data)
 			break;
-		start = (start + bsz) & ~(bsz - 1);
+		start = (start + bsz) & ~((u64)bsz - 1);
 		offset += bsz;
 	} while (offset < folio_size(folio));
 unlock:
