From 2e06c57d66d3f6c26faa5f5b479fb3add34ce85a Mon Sep 17 00:00:00 2001 From: Larysa Zaremba Date: Tue, 11 Jul 2023 12:59:26 +0200 Subject: xdp: use trusted arguments in XDP hints kfuncs Currently, verifier does not reject XDP programs that pass NULL pointer to hints functions. At the same time, this case is not handled in any driver implementation (including veth). For example, changing bpf_xdp_metadata_rx_timestamp(ctx, ×tamp); to bpf_xdp_metadata_rx_timestamp(ctx, NULL); in xdp_metadata test successfully crashes the system. Add KF_TRUSTED_ARGS flag to hints kfunc definitions, so driver code does not have to worry about getting invalid pointers. Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs") Reported-by: Stanislav Fomichev Closes: https://lore.kernel.org/bpf/ZKWo0BbpLfkZHbyE@google.com/ Signed-off-by: Larysa Zaremba Acked-by: Jesper Dangaard Brouer Acked-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20230711105930.29170-1-larysa.zaremba@intel.com Signed-off-by: Alexei Starovoitov --- net/core/xdp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/core/xdp.c b/net/core/xdp.c index 41e5ca8643ec..8362130bf085 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -741,7 +741,7 @@ __bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash, __diag_pop(); BTF_SET8_START(xdp_metadata_kfunc_ids) -#define XDP_METADATA_KFUNC(_, name) BTF_ID_FLAGS(func, name, 0) +#define XDP_METADATA_KFUNC(_, name) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS) XDP_METADATA_KFUNC_xxx #undef XDP_METADATA_KFUNC BTF_SET8_END(xdp_metadata_kfunc_ids) -- cgit v1.2.3