diff options
| author | Eduard Zingerman <eddyz87@gmail.com> | 2025-04-23 13:53:27 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-25 10:48:08 +0200 |
| commit | 1062b7612cbd19ea25ccac9a29b25353b67141cc (patch) | |
| tree | d1b7aecc35d3be9110cdb176d3d7150013337e31 | |
| parent | d0e94a5bb99df7905dcdd3d27661d0545b18f3c5 (diff) | |
selftests/bpf: validate that tail call invalidates packet pointers
commit d9706b56e13b7916461ca6b4b731e169ed44ed09 upstream.
Add a test case with a tail call done from a global sub-program. Such
tails calls should be considered as invalidating packet pointers.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20241210041100.1898468-9-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_sock.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_sock.c b/tools/testing/selftests/bpf/progs/verifier_sock.c index e85f0f1deac7..3c8f6646e33d 100644 --- a/tools/testing/selftests/bpf/progs/verifier_sock.c +++ b/tools/testing/selftests/bpf/progs/verifier_sock.c @@ -50,6 +50,13 @@ struct { __uint(map_flags, BPF_F_NO_PREALLOC); } sk_storage_map SEC(".maps"); +struct { + __uint(type, BPF_MAP_TYPE_PROG_ARRAY); + __uint(max_entries, 1); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(__u32)); +} jmp_table SEC(".maps"); + SEC("cgroup/skb") __description("skb->sk: no NULL check") __failure __msg("invalid mem access 'sock_common_or_null'") @@ -1005,4 +1012,25 @@ int invalidate_pkt_pointers_from_global_func(struct __sk_buff *sk) return TCX_PASS; } +__noinline +int tail_call(struct __sk_buff *sk) +{ + bpf_tail_call_static(sk, &jmp_table, 0); + return 0; +} + +/* Tail calls invalidate packet pointers. */ +SEC("tc") +__failure __msg("invalid mem access") +int invalidate_pkt_pointers_by_tail_call(struct __sk_buff *sk) +{ + int *p = (void *)(long)sk->data; + + if ((void *)(p + 1) > (void *)(long)sk->data_end) + return TCX_DROP; + tail_call(sk); + *p = 42; /* this is unsafe */ + return TCX_PASS; +} + char _license[] SEC("license") = "GPL"; |