bpf_xdp_link_update() calls dev_xdp_install() directly and skips dev_xdp_attach(), so the checks in dev_xdp_attach() do not run. A user can make an XDP link with a normal program and then swap in an offloaded or device-bound program with BPF_LINK_UPDATE, which puts it on the software path. Move the three program checks (offloaded, bound to another device, and device-bound in generic mode) from dev_xdp_attach() into dev_xdp_install(), so both the attach path and the link update path are covered. Fixes: 026a4c28e1db3 ("bpf, xdp: Implement LINK_UPDATE for BPF XDP link") Signed-off-by: Jiayuan Chen --- net/core/dev.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index af260ff5462a..3281f226c1e5 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -10329,6 +10329,21 @@ static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode, netdev_assert_locked_ops_compat(dev); + if (prog) { + if (mode != XDP_MODE_HW && bpf_prog_is_offloaded(prog->aux)) { + NL_SET_ERR_MSG(extack, "Using offloaded program without HW_MODE flag is not supported"); + return -EINVAL; + } + if (bpf_prog_is_dev_bound(prog->aux) && !bpf_offload_dev_match(prog, dev)) { + NL_SET_ERR_MSG(extack, "Program bound to different device"); + return -EINVAL; + } + if (bpf_prog_is_dev_bound(prog->aux) && mode == XDP_MODE_SKB) { + NL_SET_ERR_MSG(extack, "Can't attach device-bound programs in generic mode"); + return -EINVAL; + } + } + if (dev->cfg->hds_config == ETHTOOL_TCP_DATA_SPLIT_ENABLED && prog && !prog->aux->xdp_has_frags) { NL_SET_ERR_MSG(extack, "unable to install XDP to device using tcp-data-split"); @@ -10480,18 +10495,6 @@ static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time"); return -EEXIST; } - if (!offload && bpf_prog_is_offloaded(new_prog->aux)) { - NL_SET_ERR_MSG(extack, "Using offloaded program without HW_MODE flag is not supported"); - return -EINVAL; - } - if (bpf_prog_is_dev_bound(new_prog->aux) && !bpf_offload_dev_match(new_prog, dev)) { - NL_SET_ERR_MSG(extack, "Program bound to different device"); - return -EINVAL; - } - if (bpf_prog_is_dev_bound(new_prog->aux) && mode == XDP_MODE_SKB) { - NL_SET_ERR_MSG(extack, "Can't attach device-bound programs in generic mode"); - return -EINVAL; - } if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) { NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device"); return -EINVAL; -- 2.43.0