From: Alexei Starovoitov <ast@kernel.org>
To: <davem@davemloft.net>
Cc: <daniel@iogearbox.net>, <netdev@vger.kernel.org>,
<bpf@vger.kernel.org>, <kernel-team@fb.com>
Subject: [PATCH bpf-next 2/2] bpf: drop bpf_verifier_lock
Date: Fri, 19 Apr 2019 07:44:55 -0700 [thread overview]
Message-ID: <20190419144455.853134-3-ast@kernel.org> (raw)
In-Reply-To: <20190419144455.853134-1-ast@kernel.org>
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>
---
kernel/bpf/verifier.c | 8 +++++---
1 file 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 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
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);
--
2.20.0
next prev parent reply other threads:[~2019-04-19 18:58 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-19 14:44 [PATCH bpf-next 0/2] bpf: parallel verification Alexei Starovoitov
2019-04-19 14:44 ` [PATCH bpf-next 1/2] bpf: remove global variables Alexei Starovoitov
2019-04-19 14:44 ` Alexei Starovoitov [this message]
2019-04-19 19:34 ` [PATCH bpf-next 0/2] bpf: parallel verification Andrii Nakryiko
2019-04-22 23:58 ` Daniel Borkmann
2019-04-23 0:06 ` Alexei Starovoitov
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