[PATCH RFC v1 09/15] xdp: clear grow memory in bpf_xdp_adjust_tail()

[Jesper Dangaard Brouer <brouer@xxxxxxxxxx>]

To reviewers: Need some opinions if this is needed?

(TODO: Squash patch)
---
 net/core/filter.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c
index 0ceddee0c678..669f29992177 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3432,6 +3432,12 @@ BPF_CALL_2(bpf_xdp_adjust_tail, struct xdp_buff *, xdp, int, offset)
 	if (unlikely(data_end < xdp->data + ETH_HLEN))
 		return -EINVAL;
 
+	// XXX: To reviewers: How paranoid are we? Do we really need to
+	/* clear memory area on grow, as in-theory can contain uninit kmem */
+	if (offset > 0) {
+		memset(xdp->data_end, 0, offset);
+	}
+
 	xdp->data_end = data_end;
 
 	return 0;