diff options
| author | Eduard Zingerman <eddyz87@gmail.com> | 2024-12-09 20:10:56 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-12-10 10:24:57 -0800 |
| commit | 3f23ee5590d9605dbde9a5e1d4b97637a4803329 (patch) | |
| tree | ba5bbd7b1d1644892c1ee453a6050e85412080b3 /tools/testing/selftests/bpf/progs/verifier_sock.c | |
| parent | 51081a3f25c742da5a659d7fc6fd77ebfdd555be (diff) | |
selftests/bpf: test for changing packet data from global functions
Check if verifier is aware of packet pointers invalidation done in
global functions. Based on a test shared by Nick Zavaritsky in [0].
[0] https://lore.kernel.org/bpf/0498CA22-5779-4767-9C0C-A9515CEA711F@gmail.com/
Suggested-by: Nick Zavaritsky <mejedi@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20241210041100.1898468-5-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/progs/verifier_sock.c')
| -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 d3e70e38e442..51826379a1aa 100644 --- a/tools/testing/selftests/bpf/progs/verifier_sock.c +++ b/tools/testing/selftests/bpf/progs/verifier_sock.c @@ -1037,4 +1037,32 @@ __naked void sock_create_read_src_port(void) : __clobber_all); } +__noinline +long skb_pull_data2(struct __sk_buff *sk, __u32 len) +{ + return bpf_skb_pull_data(sk, len); +} + +__noinline +long skb_pull_data1(struct __sk_buff *sk, __u32 len) +{ + return skb_pull_data2(sk, len); +} + +/* global function calls bpf_skb_pull_data(), which invalidates packet + * pointers established before global function call. + */ +SEC("tc") +__failure __msg("invalid mem access") +int invalidate_pkt_pointers_from_global_func(struct __sk_buff *sk) +{ + int *p = (void *)(long)sk->data; + + if ((void *)(p + 1) > (void *)(long)sk->data_end) + return TCX_DROP; + skb_pull_data1(sk, 0); + *p = 42; /* this is unsafe */ + return TCX_PASS; +} + char _license[] SEC("license") = "GPL"; |