On Wed, Feb 1, 2023 at 10:13 AM Jesper Dangaard Brouer
<brouer@xxxxxxxxxx> wrote:
>
> 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>
Good catch, thank you!
Acked-by: Stanislav Fomichev <sdf@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)
>
>
