From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-vs2-f12.google.com (mail-vs2-f12.google.com [74.125.227.12]) (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 CD89C4BA1D3 for ; Tue, 15 Sep 2026 17:30:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.227.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789493418; cv=none; b=t6+CL6PcTNPMd4itCwaCf9v7+kgsPcxRw7aZjBKRnBHtQ1I9HFbXq4+NqH/VDlhs4NMprKzRrgL49Y0nJdUEX/b5kYEEOnCmABaiwNYLMD4jl3lGI/vEucqV2z5QUiLiZcmQw84VxhkApaF0pc07j5CckydCjYjb99VQbDOeIMc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789493418; c=relaxed/simple; bh=VwBUcuZPFg1BLZxP9DxF8spw7i/So+6y5IlyEFSLMuc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Y5YB+4guQ8ObhYW62tmqYC2ZP+Th2hwxAAhoPzz4lYd3qY8VnmxWeZtGcuLDYUr3HATssycy8g6HhxI0403Pg3LHL2mqkYXKBLgWk07pdZ4drb7lvQ4fTrFC0fBrf8u0EiCmETjfP13KNZQd3HQd6wG4cvmECrOYBXl6UYYGngE= 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=FExjj1uo; arc=none smtp.client-ip=74.125.227.12 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="FExjj1uo" Received: by mail-vs2-f12.google.com with SMTP id 71dfb90a1353d-5c67e4d8d8aso2955303e0c.1 for ; Tue, 15 Sep 2026 10:30:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1789493415; x=1790098215; darn=lists.linux.dev; h=content-transfer-encoding:content-type:mime-version:references :in-reply-to:message-id:date:subject:cc:to:from:from:to:cc:subject :date:message-id:reply-to:content-type; bh=VwBUcuZPFg1BLZxP9DxF8spw7i/So+6y5IlyEFSLMuc=; b=FExjj1uo4MKfwYbbjxVdcS8gZVjDTCWN3Shkzw1sd3yHnfl2tZ67FWu75vSMB4I7O6 6L7c5PzgCMaU6KHrbfiSenjdOANWG0zzy7Y2qDztzeME3L+9vDiXO5H0Z5igxq01lk1e /b7NJzP360sLwyZr1w+0G8nO1oSEZWaEOEJC4bqgvs9H4sFt+U2UU8HqWPgUkFpXwqt1 lGzZmO+rckfjzImOq/ZwHj9x3DY8oZDV0cajNJg+N5JghTcv/LXXgHvaIj42txijWrTh wf5puRrjUOVGbUHO1QhKVOmgELaby55juu3u9Rj41MdIjp/mHjClAnG0yAAtHhkb2fLu TrhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789493415; x=1790098215; h=content-transfer-encoding:content-type: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 :content-type; bh=VwBUcuZPFg1BLZxP9DxF8spw7i/So+6y5IlyEFSLMuc=; b=QLG8hiQbXSzlQ7VlTuHTVlw8Xzjw/suKqWO7PhVuIaMyjqD667kBj2okE+5vcLcid9 au9oP8o70evnVdmZu+o9/zQNM0LUi3bJ9NwxXR8Wdh/Ix25S+15jDWspRxEOXc6wGuwh hr1S7AeEfqxMI8GyCQSEbEmVNkn8AHDANRbRsZGwo0o8vnRiiuQZ6TsKH2aidKE1lwzj 6W1eudsq0xM2wx2gZNU5A+hRhpPP5unMabCIUtFQ0ZDHyOVhvBVBS4ZaDrySHlsDr/pg Q7+iLZttSjKDRxgRM5jG7zRvCVcuq6QryzFzG/thvjbQeXTu+/7qwM/X/POp+OIb0a/s NOew== X-Forwarded-Encrypted: i=1; AKwUvBxvOsPsaKCipwqp6O1kFZKGX/oPsSFixWwVM9fxcHYySMVsWj3Z0oQFqspl013osr+r8DtjLQkEv/0uXto7wQ==@lists.linux.dev X-Gm-Message-State: AFuF++md+sAaqXJdyJEj1GttmXOMMmsipYRMszBtyKW8R+PKlD/VP4hs rS25SDknQaJYkFDDvQbqvXxzqCJkYQCnJ9XVqEJYEJa6cSlVPncw0OKA X-Gm-Gg: AYBFou0iqrfI6G7zk66rvA4QpPPq01n/CZ7P6F8pZ19I3YWoIVEMsxGCkkBPKuuGUVl PLRQSve0+F0Zww5dHLifJ02ifns/Aj2QhfRr6GTyxJViCUkqi+k7YDNLtZgQGXH52aCi1qSnuzT l3pky/MI6D79uF3WQseYVgXbuj4GbLSM30MDGBPdt/wMUDLCB/f+nzVpVrrA2Sh16uz3m+CTKDd K3Cf3mMiEDbsgGivGpIgvr48FZajQ9vS71ltXy0tpROQ2+0ftbos0v3oZPfEZ5iix5sAAuGpiPU QR+CW0okOSuotRvsLEkg3EIm3q5UCDNVK8bbl/rcKrqw9SXxfZiHZVSMfimyq+BNxgifnYQc2wi mgc2JAI6SyknPwBneAdp6XoCpvccKs1bsyzApWJRYxeXblgG41At01hjEWouYHZi31PNsaKxSKG y0zgAOeU6Ajrgt3uKTQMTQ8x6fhulU6JIZQC5KQV0cYM36fs0IewSUHUiA1wn17WoB X-Received: by 2002:a05:6122:894:b0:5c7:ebed:1018 with SMTP id 71dfb90a1353d-5c981d87e33mr5580194e0c.8.1789493415229; Tue, 15 Sep 2026 10:30:15 -0700 (PDT) Received: from beelink.. ([187.13.206.89]) by smtp.gmail.com with ESMTPSA id 71dfb90a1353d-5c9989fa82esm153202e0c.4.2026.09.15.10.30.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Sep 2026 10:30:14 -0700 (PDT) From: Aldo Ariel Panzardo To: Luigi Leonardi , Stefano Garzarella Cc: Bobby Eshleman , davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, virtualization@lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Aldo Ariel Panzardo Subject: Re: [PATCH v2] vsock: ignore empty child namespace mode writes Date: Tue, 15 Sep 2026 14:29:33 -0300 Message-ID: <20260915172952.3174810-1-qwe.aldo@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260915141547.3010692-1-qwe.aldo@gmail.com> References: <20260915141547.3010692-1-qwe.aldo@gmail.com> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Luigi, Stefano, Thanks for taking a look. Luigi — nothing fancy, I was just reading sysctl handlers and noticed that __vsock_net_mode_string() bails early on a zero-length write without touching new_mode. Since the child mode can only be set once, an empty write that sneaks through locks it with whatever was on the stack. CONFIG_INIT_STACK_ALL_ZERO hides the whole thing, which is probably why nobody hit it in practice. Stefano — yeah, makes more sense to bail before calling the helper at all. Fixed in v3, and I added the CCs I missed. Cheers, Aldo