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. Acked-by: Jonathan Lemon <jonathan.lemon@xxxxxxxxx> 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 8fafa3ce3ae6..e3e99ee5631b 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -716,7 +716,7 @@ 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