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authorMatthew Wilcox (Oracle) <willy@infradead.org>2020-10-13 08:46:29 -0400
committerMatthew Wilcox (Oracle) <willy@infradead.org>2020-10-13 08:53:29 -0400
commit84c34df158cf215b0cd1475ab3b8e6f212f81f23 (patch)
tree744410b0a8b2a36fa895e0e1033bb7ec93c1cbd8
parentf78b8250a076ac63ddd021c7ea9739bcc2f6f737 (diff)
XArray: Fix xas_create_range for ranges above 4 billion
The 'sibs' variable would be shifted as a 32-bit integer, so if 'shift' is more than 32, this is undefined behaviour. In practice, this doesn't happen because the page cache is the only user and nobody uses 16TB pages. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
-rw-r--r--lib/xarray.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/xarray.c b/lib/xarray.c
index 1fa5c5658e63..2046d676ab41 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -703,7 +703,7 @@ void xas_create_range(struct xa_state *xas)
unsigned char shift = xas->xa_shift;
unsigned char sibs = xas->xa_sibs;
- xas->xa_index |= ((sibs + 1) << shift) - 1;
+ xas->xa_index |= ((sibs + 1UL) << shift) - 1;
if (xas_is_node(xas) && xas->xa_node->shift == xas->xa_shift)
xas->xa_offset |= sibs;
xas->xa_shift = 0;