From: Björn Töpel <bjorn.topel@xxxxxxxxx>
The umem member of struct xdp_sock is read outside of the control
mutex, in the mmap implementation, and needs a WRITE_ONCE to avoid
potentional store-tearing.
Fixes: 423f38329d26 ("xsk: add umem fill queue support and mmap")
Signed-off-by: Björn Töpel <bjorn.topel@xxxxxxxxx>
---
net/xdp/xsk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 31236e61069b..6dde1857ed52 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -718,7 +718,7 @@ static int xsk_setsockopt(struct socket *sock, int level, int optname,
/* Make sure umem is ready before it can be seen by others */
smp_wmb();
- xs->umem = umem;
+ WRITE_ONCE(xs->umem, umem);
mutex_unlock(&xs->mutex);
return 0;
}
--
2.20.1
