bpf, mlx5: fix mlx5e_create_rq taking reference on prog (97bc402d) · Commits · 戴 / test

In mlx5e_create_rq(), when creating a new queue, we call bpf_prog_add() but without checking the return value. bpf_prog_add() can fail since ("bpf: fix refcnt overflow"), so we really must check it. Take the reference right when we assign it to the rq from priv->xdp_prog, and just drop the reference on error path. Destruction in mlx5e_destroy_rq() looks good, though. Fixes: ("net/mlx5e: XDP fast RX drop bpf programs support") Signed-off-by:

Daniel Borkmann <daniel@iogearbox.net> Acked-by:

Saeed Mahameed <saeedm@mellanox.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx5/core/en_main.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -513,7 +513,13 @@ static int mlx5e_create_rq(struct mlx5e_channel *c,
		rq->channel = c;
		rq->ix = c->ix;
		rq->priv = c->priv;
		rq->xdp_prog = priv->xdp_prog;

		rq->xdp_prog = priv->xdp_prog ? bpf_prog_inc(priv->xdp_prog) : NULL;
		if (IS_ERR(rq->xdp_prog)) {
		err = PTR_ERR(rq->xdp_prog);
		rq->xdp_prog = NULL;
		goto err_rq_wq_destroy;
		}

		rq->buff.map_dir = DMA_FROM_DEVICE;
		if (rq->xdp_prog)
		@@ -590,12 +596,11 @@ static int mlx5e_create_rq(struct mlx5e_channel *c,
		rq->page_cache.head = 0;
		rq->page_cache.tail = 0;

		if (rq->xdp_prog)
		bpf_prog_add(rq->xdp_prog, 1);

		return 0;

		err_rq_wq_destroy:
		if (rq->xdp_prog)
		bpf_prog_put(rq->xdp_prog);
		mlx5_wq_destroy(&rq->wq_ctrl);

		return err;

kernel/bpf/syscall.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -696,6 +696,7 @@ struct bpf_prog bpf_prog_inc(struct bpf_prog prog)
		{
		return bpf_prog_add(prog, 1);
		}
		EXPORT_SYMBOL_GPL(bpf_prog_inc);

		static struct bpf_prog __bpf_prog_get(u32 ufd, enum bpf_prog_type type)
		{

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