[PATCH AUTOSEL 4.14 1/5] netlabel: fix shift wrapping bug in netlbl_catmap_setlong()

[Sasha Levin]

From: Dmitry Mastykin <dmastykin@xxxxxxxxxxxxx>

[ Upstream commit b403643d154d15176b060b82f7fc605210033edd ]

There is a shift wrapping bug in this code on 32-bit architectures.
NETLBL_CATMAP_MAPTYPE is u64, bitmap is unsigned long.
Every second 32-bit word of catmap becomes corrupted.

Signed-off-by: Dmitry Mastykin <dmastykin@xxxxxxxxxxxxx>
Acked-by: Paul Moore <paul@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/netlabel/netlabel_kapi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index 15fe2120b3109..14c3d640f94b9 100644
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -871,7 +871,8 @@ int netlbl_catmap_setlong(struct netlbl_lsm_catmap **catmap,
 
 	offset -= iter->startbit;
 	idx = offset / NETLBL_CATMAP_MAPSIZE;
-	iter->bitmap[idx] |= bitmap << (offset % NETLBL_CATMAP_MAPSIZE);
+	iter->bitmap[idx] |= (NETLBL_CATMAP_MAPTYPE)bitmap
+			     << (offset % NETLBL_CATMAP_MAPSIZE);
 
 	return 0;
 }
-- 
2.40.1