From: Kuniyuki Iwashima <kuniyu@google.com>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>
Cc: John Fastabend <john.fastabend@gmail.com>,
Eduard Zingerman <eddyz87@gmail.com>, Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@fomichev.me>,
Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>,
Michal Luczaj <mhal@rbox.co>,
Kuniyuki Iwashima <kuniyu@google.com>,
Kuniyuki Iwashima <kuni1840@gmail.com>,
bpf@vger.kernel.org, netdev@vger.kernel.org
Subject: [PATCH v1 bpf 0/2] bpf: Reject access to unix_sk(sk)->{peer,listener}.
Date: Sat, 7 Feb 2026 23:07:09 +0000 [thread overview]
Message-ID: <20260207230720.2542943-1-kuniyu@google.com> (raw)
Accessing unix_sk(sk)->{peer,listener} is only safe under
unix_state_lock().
There are many functions where bpf prog can access the fields
locklessly via fentry/fexit or bpf iter.
unix_sk(sk)->{peer,listener} could go away during such lockless
access by bpf.
This seires marks the fields with PTR_UNTRUSTED to prevent
such use-after-free.
Kuniyuki Iwashima (2):
bpf: Reject access to unix_sk(sk)->peer.
bpf: Reject access to unix_sk(sk)->listener.
kernel/bpf/verifier.c | 19 +++++++
.../selftests/bpf/progs/verifier_sock.c | 49 +++++++++++++++++++
2 files changed, 68 insertions(+)
--
2.53.0.rc2.204.g2597b5adb4-goog
next reply other threads:[~2026-02-07 23:07 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-07 23:07 Kuniyuki Iwashima [this message]
2026-02-07 23:07 ` [PATCH v1 bpf 1/2] bpf: Reject access to unix_sk(sk)->peer Kuniyuki Iwashima
2026-02-09 23:00 ` Alexei Starovoitov
2026-02-10 1:19 ` Kuniyuki Iwashima
2026-02-11 2:47 ` Alexei Starovoitov
2026-02-11 4:23 ` Kuniyuki Iwashima
2026-02-11 21:25 ` Alexei Starovoitov
2026-02-11 22:22 ` Kuniyuki Iwashima
2026-02-11 22:39 ` Alexei Starovoitov
2026-02-11 23:01 ` Kuniyuki Iwashima
2026-02-07 23:07 ` [PATCH v1 bpf 2/2] bpf: Reject access to unix_sk(sk)->listener Kuniyuki Iwashima
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