From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-46.mta1.migadu.com [95.215.58.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D5F5E4AA566 for ; Thu, 3 Sep 2026 12:53:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.46 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788440003; cv=none; b=I1KKvsI9m6Qw1bQXJE7h7nrEL9uTdoOCu3nsl4q+F/oectjJt22h3b5TsVnDWeEscY4qJ4bFmv79yUi/jBo+YwuSq6DwbGma256RqkHaaEYjgQhTbIw/FOZox/xgzcnIp9+yjEKQIOAdtC33r1Nam7hDuZBnpcgn8gmkfqDLubE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788440003; c=relaxed/simple; bh=UlTZVZlpxTLFXO8JJRdJ8MXuTqmOeVcpCsf//AOZZCE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=MybLAPSiERq57npSPPnhv3JQPPXqLbdke+CnCk8Z6FeHp3qtUz8xRGvsTuN4EcKkfbDO5xeVMyaa7SIKncsgaSpUBksLSbY8zVYMZK6istbkodr386kIddk7qel6mBXPPzfM4TXxLZws+nt0B8WNpFCH+7tDV0LA+Z95reivuu4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=bZgCCfHJ; arc=none smtp.client-ip=95.215.58.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="bZgCCfHJ" X-Envelope-To: netdev@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=UlTZVZlpxTLFXO8JJRdJ8MXuTqmOeVcpCsf//AOZZCE=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1788439998; v=1; x=1789044798; b=bZgCCfHJwIyAAkUIHMriFrmR1b1F7tyZwl3fdu9z9UCeZsj2Ep7DEIyUSEmgF+ZhMVLWiEvw zyYYk1BeX8qgwCaCvP8majsvebQqpmTIzeIQAVPXlFPzTB95++c2u/q1A+GTnGmeZszJFKDFLtf gi3y7yEVr4Bab5NY9KUjsef4= X-Envelope-To: netdev@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 5ce3ad7db0c8ff24; Thu, 03 Sep 2026 12:53:18 +0000 X-Mizu-Trace-ID: 5ce3ad7db0c8ff24 X-Migadu-Flow: FLOW_OUT From: Jiayuan Chen To: bpf@vger.kernel.org Cc: Jiayuan Chen , Xiang Mei , Daniel Borkmann , John Fastabend , Stanislav Fomichev , Martin KaFai Lau , Alexei Starovoitov , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Ihor Solodrai , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Shuah Khan , Aditi Ghag , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH bpf 1/2] bpf: Fix out-of-bounds read of sk_protocol in bpf_sock_destroy() Date: Thu, 3 Sep 2026 20:52:48 +0800 Message-ID: <20260903125306.299943-1-jiayuan.chen@linux.dev> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit sk_protocol lives in struct sock, not in struct sock_common. A timewait or request sock handed to bpf_sock_destroy() by the tcp iterator is neither, so reading sk->sk_protocol runs past the object: ================================================================== BUG: KASAN: slab-out-of-bounds in bpf_sock_destroy+0xc7/0xe0 Read of size 2 at addr ffff8881047d11b4 by task test_progs/428 Tainted: [W]=WARN Call Trace: dump_stack_lvl+0x91/0xf0 print_report+0xd1/0x630 kasan_report+0xf3/0x130 __asan_report_load2_noabort+0x14/0x30 bpf_sock_destroy+0xc7/0xe0 bpf_prog_c3dd61f9d9cd9f37_iter_tcp6_timewait+0x9f/0xb7 bpf_iter_run_prog+0x538/0xde0 bpf_iter_tcp_seq_show+0x26b/0x4b0 bpf_seq_read+0x424/0x1210 vfs_read+0x197/0xe40 ksys_read+0x119/0x240 __x64_sys_read+0x72/0xc0 x64_sys_call+0x647/0x27e0 do_syscall_64+0xe5/0x610 entry_SYSCALL_64_after_hwframe+0x76/0x7e Only check sk_protocol on full socks. tcp_abort() already knows how to deal with TIME_WAIT and NEW_SYN_RECV socks. Also fix the comment, it never matched the code. Fixes: 4ddbcb886268 ("bpf: Add bpf_sock_destroy kfunc") Reported-by: Xiang Mei (Microsoft) Closes: https://lore.kernel.org/bpf/20260702224519.800135-1-xmei5@asu.edu/ Signed-off-by: Jiayuan Chen --- net/core/filter.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 61940e753552..1bbb72138ac6 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -12912,8 +12912,8 @@ __bpf_kfunc_start_defs(); * @sock: Pointer to socket to be destroyed * * Return: - * On error, may return EPROTONOSUPPORT, EINVAL. - * EPROTONOSUPPORT if protocol specific destroy handler is not supported. + * On error, may return EOPNOTSUPP, EINVAL. + * EOPNOTSUPP if protocol specific destroy handler is not supported. * 0 otherwise */ __bpf_kfunc int bpf_sock_destroy(struct sock_common *sock) @@ -12925,8 +12925,12 @@ __bpf_kfunc int bpf_sock_destroy(struct sock_common *sock) * Supporting protocols will need to acquire sock lock in the BPF context * prior to invoking this kfunc. */ - if (!sk->sk_prot->diag_destroy || (sk->sk_protocol != IPPROTO_TCP && - sk->sk_protocol != IPPROTO_UDP)) + if (!sk->sk_prot->diag_destroy) + return -EOPNOTSUPP; + + if (sk_fullsock(sk) && + sk->sk_protocol != IPPROTO_TCP && + sk->sk_protocol != IPPROTO_UDP) return -EOPNOTSUPP; return sk->sk_prot->diag_destroy(sk, ECONNABORTED); -- 2.43.0