From a63bf556160fb19591183383da6757f52119981d Mon Sep 17 00:00:00 2001 From: Jakub Sitnicki Date: Mon, 27 May 2024 13:20:09 +0200 Subject: selftests/bpf: Cover verifier checks for mutating sockmap/sockhash Verifier enforces that only certain program types can mutate sock{map,hash} maps, that is update it or delete from it. Add test coverage for these checks so we don't regress. Signed-off-by: Jakub Sitnicki Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20240527-sockmap-verify-deletes-v1-3-944b372f2101@cloudflare.com --- .../selftests/bpf/progs/verifier_sockmap_mutate.c | 187 +++++++++++++++++++++ 1 file changed, 187 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/verifier_sockmap_mutate.c (limited to 'tools/testing/selftests/bpf/progs/verifier_sockmap_mutate.c') diff --git a/tools/testing/selftests/bpf/progs/verifier_sockmap_mutate.c b/tools/testing/selftests/bpf/progs/verifier_sockmap_mutate.c new file mode 100644 index 000000000000..fe4b123187b8 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/verifier_sockmap_mutate.c @@ -0,0 +1,187 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include + +#include "bpf_misc.h" + +#define __always_unused __attribute__((unused)) + +char _license[] SEC("license") = "GPL"; + +struct sock { +} __attribute__((preserve_access_index)); + +struct bpf_iter__sockmap { + union { + struct sock *sk; + }; +} __attribute__((preserve_access_index)); + +struct { + __uint(type, BPF_MAP_TYPE_SOCKHASH); + __uint(max_entries, 1); + __type(key, int); + __type(value, int); +} sockhash SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_SOCKMAP); + __uint(max_entries, 1); + __type(key, int); + __type(value, int); +} sockmap SEC(".maps"); + +enum { CG_OK = 1 }; + +int zero = 0; + +static __always_inline void test_sockmap_delete(void) +{ + bpf_map_delete_elem(&sockmap, &zero); + bpf_map_delete_elem(&sockhash, &zero); +} + +static __always_inline void test_sockmap_update(void *sk) +{ + if (sk) { + bpf_map_update_elem(&sockmap, &zero, sk, BPF_ANY); + bpf_map_update_elem(&sockhash, &zero, sk, BPF_ANY); + } +} + +static __always_inline void test_sockmap_lookup_and_update(void) +{ + struct bpf_sock *sk = bpf_map_lookup_elem(&sockmap, &zero); + + if (sk) { + test_sockmap_update(sk); + bpf_sk_release(sk); + } +} + +static __always_inline void test_sockmap_mutate(void *sk) +{ + test_sockmap_delete(); + test_sockmap_update(sk); +} + +static __always_inline void test_sockmap_lookup_and_mutate(void) +{ + test_sockmap_delete(); + test_sockmap_lookup_and_update(); +} + +SEC("action") +__success +int test_sched_act(struct __sk_buff *skb) +{ + test_sockmap_mutate(skb->sk); + return 0; +} + +SEC("classifier") +__success +int test_sched_cls(struct __sk_buff *skb) +{ + test_sockmap_mutate(skb->sk); + return 0; +} + +SEC("flow_dissector") +__success +int test_flow_dissector_delete(struct __sk_buff *skb __always_unused) +{ + test_sockmap_delete(); + return 0; +} + +SEC("flow_dissector") +__failure __msg("program of this type cannot use helper bpf_sk_release") +int test_flow_dissector_update(struct __sk_buff *skb __always_unused) +{ + test_sockmap_lookup_and_update(); /* no access to skb->sk */ + return 0; +} + +SEC("iter/sockmap") +__success +int test_trace_iter(struct bpf_iter__sockmap *ctx) +{ + test_sockmap_mutate(ctx->sk); + return 0; +} + +SEC("raw_tp/kfree") +__failure __msg("cannot update sockmap in this context") +int test_raw_tp_delete(const void *ctx __always_unused) +{ + test_sockmap_delete(); + return 0; +} + +SEC("raw_tp/kfree") +__failure __msg("cannot update sockmap in this context") +int test_raw_tp_update(const void *ctx __always_unused) +{ + test_sockmap_lookup_and_update(); + return 0; +} + +SEC("sk_lookup") +__success +int test_sk_lookup(struct bpf_sk_lookup *ctx) +{ + test_sockmap_mutate(ctx->sk); + return 0; +} + +SEC("sk_reuseport") +__success +int test_sk_reuseport(struct sk_reuseport_md *ctx) +{ + test_sockmap_mutate(ctx->sk); + return 0; +} + +SEC("socket") +__success +int test_socket_filter(struct __sk_buff *skb) +{ + test_sockmap_mutate(skb->sk); + return 0; +} + +SEC("sockops") +__success +int test_sockops_delete(struct bpf_sock_ops *ctx __always_unused) +{ + test_sockmap_delete(); + return CG_OK; +} + +SEC("sockops") +__failure __msg("cannot update sockmap in this context") +int test_sockops_update(struct bpf_sock_ops *ctx) +{ + test_sockmap_update(ctx->sk); + return CG_OK; +} + +SEC("sockops") +__success +int test_sockops_update_dedicated(struct bpf_sock_ops *ctx) +{ + bpf_sock_map_update(ctx, &sockmap, &zero, BPF_ANY); + bpf_sock_hash_update(ctx, &sockhash, &zero, BPF_ANY); + return CG_OK; +} + +SEC("xdp") +__success +int test_xdp(struct xdp_md *ctx __always_unused) +{ + test_sockmap_lookup_and_mutate(); + return XDP_PASS; +} -- cgit v1.2.3