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| author |   Alexei Starovoitov <ast@kernel.org> | 2019-04-19 07:44:55 -0700 |
|---|---|---|
| committer |   Daniel Borkmann <daniel@iogearbox.net> | 2019-04-23 01:50:43 +0200 |
| commit | 45a73c17bfb92c3ceebedc80a750ef2c2931c26b (patch) | |
| tree | b87c6007123c872988d8939f8206a8ec8907bb39 /kernel | |
| parent | bpf: remove global variables (diff) | |
| download | linux-dev-45a73c17bfb92c3ceebedc80a750ef2c2931c26b.tar.xz linux-dev-45a73c17bfb92c3ceebedc80a750ef2c2931c26b.zip | |
bpf: drop bpf_verifier_lock
Drop bpf_verifier_lock for root to avoid being DoS-ed by unprivileged.
The BPF verifier is now fully parallel.
All unpriv users are still serialized by bpf_verifier_lock to avoid
exhausting kernel memory by running N parallel verifications.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 5f0eb5bd5589..423f242a5efb 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -8132,9 +8132,11 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, env->insn_aux_data[i].orig_idx = i; env->prog = *prog; env->ops = bpf_verifier_ops[env->prog->type]; + is_priv = capable(CAP_SYS_ADMIN); /* grab the mutex to protect few globals used by verifier */ - mutex_lock(&bpf_verifier_lock); + if (!is_priv) + mutex_lock(&bpf_verifier_lock); if (attr->log_level || attr->log_buf || attr->log_size) { /* user requested verbose verifier output @@ -8157,7 +8159,6 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, if (attr->prog_flags & BPF_F_ANY_ALIGNMENT) env->strict_alignment = false; - is_priv = capable(CAP_SYS_ADMIN); env->allow_ptr_leaks = is_priv; ret = replace_map_fd_with_map_ptr(env); @@ -8270,7 +8271,8 @@ err_release_maps: release_maps(env); *prog = env->prog; err_unlock: - mutex_unlock(&bpf_verifier_lock); + if (!is_priv) + mutex_unlock(&bpf_verifier_lock); vfree(env->insn_aux_data); err_free_env: kfree(env); |