From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f53.google.com (mail-pj1-f53.google.com [209.85.216.53]) (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 C6185CA5A for ; Sat, 20 Jun 2026 02:44:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781923483; cv=none; b=UqC4g+81j/99XmWh+KJgYjfCLHwbRv+VBL8D8wJlA5plg73rvLuRY/U5gHL4KFS7Wm2bO4Kv36YyH2YXvya7LWX42d3MGIZUW2jo3vOcBYKUlXiHXWIs8NZbSTO2cEYW7RiEaOUtqjrZFn2wmnoJDldUqMcB4fpp0AaojgqYCOw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781923483; c=relaxed/simple; bh=m/iiaSixnfb83KYCCVPaoDdsHHEYkoZLQwm1uMN5ZmA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uDW3Dsd2FYNr/7WiBWFOlgzmX7DL+BmM7ieOPEL0YZengUP4hT2E5xgYnsWHJ2okMhaH9UGY9rAUqNtoxIADMSYgB8d2N2ZCH8hluzYiaj6MmuMeINdunqAVYDxyg//R+Ij7tNcPP/mZ6t1QdJNmvuB1MkdpCItNXPAtbilnBPs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=dXr0xoqZ; arc=none smtp.client-ip=209.85.216.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dXr0xoqZ" Received: by mail-pj1-f53.google.com with SMTP id 98e67ed59e1d1-36c68964315so1339907a91.2 for ; Fri, 19 Jun 2026 19:44:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1781923482; x=1782528282; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Q5XmdnIL5m1N2UxN+NzNP0kc0ABgydLtyGivJ9LKVXo=; b=dXr0xoqZG4ZQRF/uDv70mNaSstEMhgyY8UeArvahH5mEp2bXQOKIl3atUrbj0ryY9s pnF4R1ZTOmde8mgHe4hwiisOFWcgRYsLXU2XDXW1kbXLvy55PVK6oYhSFpufbWQ3usLN qLG/Zd0/ZWOw0QPDZVEZ3GMCJIwbjcC42LIsfvan2IOrDUCXy4QbG9pdeEdu7OMns1L2 RWXoMDaz87o1wwEu87WWjGcOwZ+X9a0DT4PSmKMf/5pEyzvlblyVJtCpcbB828oN2Sty WfP19HxQtC7/6AmJquzuNAvwMprt1p8VBWDe9uWxH54HWLO/euQN3b48azYwUWbZxZZf MEtw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781923482; x=1782528282; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=Q5XmdnIL5m1N2UxN+NzNP0kc0ABgydLtyGivJ9LKVXo=; b=nTNGnqODlIOTdZoX7eTpk3qZ4ovmcpgySP0rsU5X+XUnp3YZmYVE/4c6BUcxFPtBgN oxjavOCxn1AsbyG4RYM/POgN8+DDfIjMM0F4rCMRZQ4p9zXJUvxe08rjn4i+RGRyw02x 43/hpsK/AUVyNHaos9xGEDYn8Co+AG/iVs4a1v64b0HMMooXPFzZd83ImwA9hRHOtb5G OgvkL43G9yprv3lopB+Ym9AJR0UWg7g4Xmr/lI+54o+XOe6cW2coal7HGt573kFo1xhD VHveILOaNqN0nN8KXPNt4JFw2Askl6dvw6wvNj51WlJ/5QKV6BYJgOSpzc2BianPPUa6 NU/g== X-Forwarded-Encrypted: i=1; AFNElJ9vB1Sgu1/GG6RKVCSPj3ckiMDuwEmciwPT5Yz5PHOOYySEWTjDYAHufRSnC5cK0poZOzAoW5o=@vger.kernel.org X-Gm-Message-State: AOJu0YyGrs+6+Je+swYHZqXKnXuJpczUfs9bZ2GrdgOGZ9Po3xn9Gjvu 8eti3bIvpbZuAVxOueFPRq4dmUJG/Le4y19QKwOLKn0XzprYNcmsB5r9 X-Gm-Gg: AfdE7cmWWhiaW3TfPSRy5dGgESIvO9uGMH3QM42dzv9+kBDye7TQxmrWn2M2OLBGPQr 9fPxw9AFQ8IXS8FB7NogM6nWkqTyMtB2mw3Jyb1bpEzhj4l4GgSU6fbSsDpHiEAX/e6hNn6LK6k EGgRmv3ivLsFFwpNWBZWOrkMD9njVkBfri/lvttidBITf/Q68r3dp14IIgJ8PT/Cm9CF49Ujcqf 8qLr1t5vmRQx6p/OffKvd088sjSBAq5XkOUbibzZFUNM7D22dKoplsPyZJlPKlAFA3ybiu3gp1i AZzpB/bR8u9Bk3Th+dkZBp5A0AfiFD4MudDeOBm2YxcHGhUrzU6f2E2tsms7wPYQmS7oG2xUQAL bMcgFFbL4MxGTRAvLza/dYDX0RRi8SU7mRf9PyZi6t3GJMRtoOMX+1az37ZnsJfFLLq5w1Hf/5M pGia1ZbZnIRDaOGYaMyw/bZ4PkAOJufjQpKsEhedC5PXrsxs948WV1RNcQ9LGGAA== X-Received: by 2002:a17:90b:4ad2:b0:369:c5f4:9681 with SMTP id 98e67ed59e1d1-37d4e8588e2mr1766868a91.22.1781923482074; Fri, 19 Jun 2026 19:44:42 -0700 (PDT) Received: from cps-manycore-1.. ([147.46.174.222]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-37d1600975asm1087971a91.0.2026.06.19.19.44.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Jun 2026 19:44:41 -0700 (PDT) From: Sechang Lim To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , John Fastabend , Jakub Sitnicki , Eduard Zingerman Cc: Eric Dumazet , Kuniyuki Iwashima , Paolo Abeni , Willem de Bruijn , "David S . Miller" , Jakub Kicinski , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Kumar Kartikeya Dwivedi , Simon Horman , Shuah Khan , Jiayuan Chen , Bobby Eshleman , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH bpf-next v5 1/3] selftests/bpf: don't modify the skb in the strparser parser prog Date: Sat, 20 Jun 2026 02:44:16 +0000 Message-ID: <20260620024423.4141004-2-rhkrqnwk98@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260620024423.4141004-1-rhkrqnwk98@gmail.com> References: <20260620024423.4141004-1-rhkrqnwk98@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit sockmap_parse_prog.c is attached as an SK_SKB stream parser and modifies the skb: it calls bpf_skb_pull_data() and writes a byte into the packet. A stream parser runs on strparser's message head and must not modify it. A resize frees the frag_list segments strparser still tracks, leading to a use-after-free. Make the parser read-only. It only needs to return the message length, which keeps it attaching once packet-modifying parsers are rejected. Reviewed-by: Jiayuan Chen Signed-off-by: Sechang Lim --- .../selftests/bpf/progs/sockmap_parse_prog.c | 22 ------------------- 1 file changed, 22 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/sockmap_parse_prog.c b/tools/testing/selftests/bpf/progs/sockmap_parse_prog.c index c9abfe3a11af..56e9aebf05f2 100644 --- a/tools/testing/selftests/bpf/progs/sockmap_parse_prog.c +++ b/tools/testing/selftests/bpf/progs/sockmap_parse_prog.c @@ -5,28 +5,6 @@ SEC("sk_skb1") int bpf_prog1(struct __sk_buff *skb) { - void *data_end = (void *)(long) skb->data_end; - void *data = (void *)(long) skb->data; - __u8 *d = data; - int err; - - if (data + 10 > data_end) { - err = bpf_skb_pull_data(skb, 10); - if (err) - return SK_DROP; - - data_end = (void *)(long)skb->data_end; - data = (void *)(long)skb->data; - if (data + 10 > data_end) - return SK_DROP; - } - - /* This write/read is a bit pointless but tests the verifier and - * strparser handler for read/write pkt data and access into sk - * fields. - */ - d = data; - d[7] = 1; return skb->len; } -- 2.43.0