diff --git a/net/core/filter.c b/net/core/filter.c index 3bb0cb98a9be3ddabea959099ff2bbbb407ab76e..a374b8560bc4991b69e35eb8c3fb3b57371598a3 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2692,6 +2692,7 @@ static unsigned long xdp_get_metalen(const struct xdp_buff *xdp) BPF_CALL_2(bpf_xdp_adjust_head, struct xdp_buff *, xdp, int, offset) { + void *xdp_frame_end = xdp->data_hard_start + sizeof(struct xdp_frame); unsigned long metalen = xdp_get_metalen(xdp); void *data_start = xdp->data_hard_start + metalen; void *data = xdp->data + offset; @@ -2700,6 +2701,13 @@ BPF_CALL_2(bpf_xdp_adjust_head, struct xdp_buff *, xdp, int, offset) data > xdp->data_end - ETH_HLEN)) return -EINVAL; + /* Avoid info leak, when reusing area prev used by xdp_frame */ + if (data < xdp_frame_end) { + unsigned long clearlen = xdp_frame_end - data; + + memset(data, 0, clearlen); + } + if (metalen) memmove(xdp->data_meta + offset, xdp->data_meta, metalen);