The function close_xsk() unmap via munmap() the wrong memory pointer. The call xsk_umem__delete(xsk->umem) have already freed xsk->umem. Thus the call to munmap(xsk->umem, UMEM_SIZE) will have unpredictable behavior that can lead to Segmentation fault elsewhere, as man page explain subsequent references to these pages will generate SIGSEGV. Fixes: e2a46d54d7a1 ("selftests/bpf: Verify xdp_metadata xdp->af_xdp path") Reported-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx> Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> --- .../selftests/bpf/prog_tests/xdp_metadata.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c index e033d48288c0..241909d71c7e 100644 --- a/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c +++ b/tools/testing/selftests/bpf/prog_tests/xdp_metadata.c @@ -121,7 +121,7 @@ static void close_xsk(struct xsk *xsk) xsk_umem__delete(xsk->umem); if (xsk->socket) xsk_socket__delete(xsk->socket); - munmap(xsk->umem, UMEM_SIZE); + munmap(xsk->umem_area, UMEM_SIZE); } static void ip_csum(struct iphdr *iph)