From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f69.google.com (mail-pj1-f69.google.com [209.85.216.69]) (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 8D7D834A791 for ; Fri, 14 Aug 2026 19:13:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786734823; cv=none; b=Ji6yHR8kgrFCIPismJYN7b+xlp4/CMP64c11sAhG28UakWetDhJ4Iixwu+A+RJgWOK7XKCanEWiY4xIaKeUex43sfrO+gVqcmGuXn/Y9bRQrkjmkkK/w35PV1oud9aKqlA0OFPcK6KoyE5+Bpi8tNGTMokIpveHFWvKOEGEsNMc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786734823; c=relaxed/simple; bh=5p4vDcOFaP8EVLCmru+xfFEOSu3zZ/sBd3hEC2MTLIM=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=kcjMMOXq5pT3CKnCcIQpAltX5fLSx2H7CPQ7jNrDSZOp35KucnARJN1Gd+QQMEYoKa2vhZfArG1nCUeR8wCO3e3BXjL93Q43jru/5UFr2G1nVdBGUUP3+jJj/ZR1R17wrqsSViHfnNlhlnXoFZIEXN8PePbQHYisi4DNNfEu8NQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--almasrymina.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=RrFDSgrU; arc=none smtp.client-ip=209.85.216.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--almasrymina.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="RrFDSgrU" Received: by mail-pj1-f69.google.com with SMTP id 98e67ed59e1d1-38ec0f510a9so2980680a91.2 for ; Fri, 14 Aug 2026 12:13:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1786734818; x=1787339618; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=wy8ZG+hsJyjx1JOOYY1/2Ksno+/B24t+7EIU7vbc/rY=; b=RrFDSgrUBQM8aDzzPxRlmUJAPze1tclVWSzNDCqGECcKNYaBqTLIUuUShj/t545fRn 0kzpupOd6PgO7FALeYGKMRhFYqiMnqPCsTWW9xN0zQUqUxIy6BGTeh3lG+KYqiR5wg1H aQ/TxECKQ9d/Q/XmbNd/9IjkG/uVzXzGfeQ9nQoggRXX9E964OMv4B63kyP8vdEL/b5F 99ecmfDcd9j3GprzDsnBilhMsg6rdFzWxVRJt0xM4rljM8pzUoYfHTwpkqzXVt8W6E2/ yuu3M6i6jTubYMbq9YwzIfaTjYpuDQwENKM1z7Fvsp/jN0vF9xxBbjVwSF6O0+LvjJ2l CzuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786734818; x=1787339618; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=wy8ZG+hsJyjx1JOOYY1/2Ksno+/B24t+7EIU7vbc/rY=; b=LHaI0Vr8YAg+txZz7ff/e3Da3nrC23e4yriAmawLOiH7FrGQszmljj0h99PdZakbGn eflMJTsWaC33rtufvbe6e7UygpB6CG+wO7hCe3+tqVc2/GYVxs1FwByMoG0RSql+rNar 2MnQA8swSyDS5R0zSOeqzy/lSBN1DakYMBNIwd0BULN+nd1+eWc+HgY3SI4SHnPcVyT7 LA/UERyBS/WfgrEYokGCgr0Dl1MTySl/zmCGucOcskkaB1OX/N4Uei9VpJDjIGn+71WP xeQdot7oysNoeGINhhEhdDE9WxN5e0AYn5wiXj0HdNsuRt6sI5bkwsDZU+KdZHpA/S6f GHAg== X-Forwarded-Encrypted: i=1; AHgh+RomMfKF1s272uSBt9mCVEhZ/2jwu9V4H37E/hT8m9Zm0e2gIDTssE9+imhwJZ0BhHBupiI5z+SKoKPDIz0=@vger.kernel.org X-Gm-Message-State: AOJu0YxIVbxTO+8yL+QsUJEnIs1cS+T6pFoydZaVNhvRn5dpYUX4a+l4 7bshn11AqbAzeEi7c4j7k7msoXWhxNz0gdjdBMKnIgPCKN1f/xroq7Pufw7ovo/Zv8EwBpRALo0 qjE83MOKidf+q3xhXyhgK+DYqng== X-Received: from dygg11.prod.google.com ([2002:a05:693c:80cb:b0:311:6294:c296]) (user=almasrymina job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:a125:b0:3c0:e6c3:224a with SMTP id adf61e73a8af0-3cc71dce94dmr8654667637.37.1786734818491; Fri, 14 Aug 2026 12:13:38 -0700 (PDT) Date: Fri, 14 Aug 2026 19:13:31 +0000 In-Reply-To: <20260814191336.187243-1-almasrymina@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260814191336.187243-1-almasrymina@google.com> X-Mailer: git-send-email 2.55.0.691.gc56d675ccc-goog Message-ID: <20260814191336.187243-2-almasrymina@google.com> Subject: [PATCH net v4 2/2] net: tcp: block mixing readable and unreadable frags From: Mina Almasry To: Jakub Kicinski , Kaiyuan Zhang , Willem de Bruijn , Eric Dumazet , Mina Almasry , Paolo Abeni , Stanislav Fomichev , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, dev@openvswitch.org Cc: "David S. Miller" , Simon Horman , Neal Cardwell , Kuniyuki Iwashima , Aaron Conole , Eelco Chaudron , Ilya Maximets , Jason Xing , Pavel Begunkov , Bobby Eshleman , Florian Westphal Content-Type: text/plain; charset="UTF-8" Protect tcp_sendmsg_locked() from mistakenly mixing readable and unreadable page fragments in the same SKB. Check that the devmem binding matches the existing SKB's readability. If a mismatch is detected, avoid collapsing and create a new segment. Fixes: bd61848900bff ("net: devmem: Implement TX path") Suggested-by: Eric Dumazet Cc: Pavel Begunkov Cc: Stanislav Fomichev Cc: Bobby Eshleman Signed-off-by: Mina Almasry --- v4: - Adopt Eric's suggestion to check 'binding' against SKB readability alongside tcp_skb_can_collapse_to(). - Drop pre-existing Reviewed-by tags due to significant implementation changes. v3: https://lore.kernel.org/r/20260811195405.3979177-2-almasrymina@google.com v2: https://lore.kernel.org/r/20260810180956.2348280-2-almasrymina@google.com v1: https://lore.kernel.org/r/20260801125308.1342897-3-almasrymina@google.com --- net/ipv4/tcp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 455441f1b6949..b4237d0e994d6 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1240,7 +1240,8 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size) trace_tcp_sendmsg_locked(sk, msg, skb, size_goal); - if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) { + if (copy <= 0 || !tcp_skb_can_collapse_to(skb) || + unlikely(skb_frags_readable(skb) != !binding)) { bool first_skb; new_segment: -- 2.55.0.691.gc56d675ccc-goog