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| author | Alexei Starovoitov <ast@kernel.org> | 2019-04-01 21:27:44 -0700 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2019-04-04 01:27:38 +0200 |
| commit | 4f73379ec5c2891598aa715c6df7ac9afdc86fbf (patch) | |
| tree | f6399a8b833f0b5d9ec8931ed9c7372186ecf6ca /kernel/bpf/verifier.c | |
| parent | 71dde681a8cea1ccff2c7b3be83c043ab6b2a977 (diff) | |
| download | lwn-4f73379ec5c2891598aa715c6df7ac9afdc86fbf.tar.gz lwn-4f73379ec5c2891598aa715c6df7ac9afdc86fbf.zip | |
bpf: verbose jump offset overflow check
Larger programs may trigger 16-bit jump offset overflow check
during instruction patching. Make this error verbose otherwise
users cannot decipher error code without printks in the verifier.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index ad3494a881da..6dcfeb44bb8e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -6932,8 +6932,13 @@ static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 of struct bpf_prog *new_prog; new_prog = bpf_patch_insn_single(env->prog, off, patch, len); - if (!new_prog) + if (IS_ERR(new_prog)) { + if (PTR_ERR(new_prog) == -ERANGE) + verbose(env, + "insn %d cannot be patched due to 16-bit range\n", + env->insn_aux_data[off].orig_idx); return NULL; + } if (adjust_insn_aux_data(env, new_prog->len, off, len)) return NULL; adjust_subprog_starts(env, off, len); |