From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f170.google.com (mail-qt1-f170.google.com [209.85.160.170]) (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 CA5D721E097 for ; Mon, 8 Jun 2026 12:22:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.170 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780921334; cv=none; b=VlHNGLVkbBIcWhP9YrKFSXHbHzo4RYxlMT9ZUVgFw/ffKiQJSm9KBGURWlOBn2dVAD6aUm7qoo//QrfUBStMFFDJIwE+vIV2i+JWopyiq4oTQQ5DAN4syWYqt1byyVMNbso+6XqDaoTFBtR0dPPFzpIZ9KrCmG7Wyfe721tkuI8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780921334; c=relaxed/simple; bh=ZNWWAVNfC9RmhryDBGopsCMLOBQ2uMLl+zRSZ1fBt4E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GnhSDfdkwI2UW71qL1NfwLEK50TrHAobfsrPd3XLtROutfBmYMS/ReMbNcHJwR6vQqN7u2dZe32ioVEzA9PxRp1XCJus+nYLHh+Kbx7bmMD2pINqsesPBHB9ydieZ8z4j9elSUfzaNxDFOcqKEcj1zPMF38JbjVHCU2EHAXNRak= 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=YxZFyBSc; arc=none smtp.client-ip=209.85.160.170 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="YxZFyBSc" Received: by mail-qt1-f170.google.com with SMTP id d75a77b69052e-517a5cafc3dso21372131cf.3 for ; Mon, 08 Jun 2026 05:22:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1780921332; x=1781526132; 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=xPe7RROwML8YBDC9iBsnC3XTfs6XjaM8KgeZwP62gHY=; b=YxZFyBScln/mLqyJheMjmyadkd6svfhMaj+b9QqT3ZtoT6IuqJqpRGNDa8r/swzqus habZjfgrawnUZq3m1H2lAJlCC49mi5zJfitljqqSOSbpRjUvYRjY82A/FERrakd/oPrm CtvqjKIy6tWie9DFLtu/8qHprbvSEM6WE4jY+pNF8saqupI3TGypU9voYF9NY/nO8CUq hNyRQW0TciOuDGEGBLRkPyu3wgu1Eclq1ozR29OphJzwpg68ZpjguzoAE+s41vRk2T/7 y4mKkqHQjJDyhrCiV2CsO9kSZ55HZVNMxAUrfYIDwuMfiQXBOcvxXSLXcS98sUi5XFIB w1Vw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780921332; x=1781526132; 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=xPe7RROwML8YBDC9iBsnC3XTfs6XjaM8KgeZwP62gHY=; b=EdI0Y/0ajlVhjTKA48EPKZy64j2jYxIo0XIjt9DzpUObo2oswbkchYPjPIPlu4wTlt Z4CmZSk5HMuGdGdNlBxbePJwgci1EMgdcOfDZ9L7gJps3deejeEM//ZuDBUb4nB8AyOs AwWwsG+Xa3KsbwM3hbbFdq5taJmr5Nz5BJQRYXeeO5u9zlRC6e1bCG7Lra8hiS4gKrgT 0SSB1k4q1VFfl/yIX4agvYUT2ve8XNa5fqrvvOapNeotsVAgyPJQi4gdUOE6vWwdg1TD jRQoG2acB2GNn9OKflUuFytCctwKKJYBUiDY72QrX3fXx94M0HGEdA/IwSq4nJ8XJ6fE lVPQ== X-Forwarded-Encrypted: i=1; AFNElJ+QI7jZAa0ILSEQ5tssi5qYZDqQvnesQo5x05UxvmFbmIVbcGHK+wen3m2P2+SonFvRWx/kEQxTYa9zjco=@vger.kernel.org X-Gm-Message-State: AOJu0YzLHg8wd5J6DPYpq9l+sD0vkTyjumKpdeq3+/YLQ0D2ReaF2VPE S1HSlG52jIEfgNlfqml4iROg4Ks9Ag+JrkrZDeGaqfxMcUM7XQuAZl7W X-Gm-Gg: Acq92OFJSfyyO9UpZBkTBqs3nIiNucekAy7R46daeM6wawxJLNeqSIKUNEqomdhssoZ 7q2fKycL+AJS6jBX2LyZ2ml6eE78KRceOazA5MFCPEymBEK+u1m10NORaNgDIAUjt0ELiOCuj1O x34r2Kqjp8NFwwypGZAZAFQrd8Q6EysFR75R2CDDsBvOe7NVFJCug39YXfV+A5qaQyaPlrkDsyO Ou/EIhgYv7u3RgFmz1UZHRuVtANWmzXj/W0gg70Myx5dOhol9ZzzDJarBF3kQnvASqrxEWJd2/X JTgv2WBZlzJXqRvPWClGDhGPEQ7b7ixuNTVn9cjpllYx+4ZhktMT8jXVkm1L2+EMfG/imgvHHpB bUysvfSjhxIfefORPcCGt7nQiYCijbJ/0HHH5zuBjPtjXicuPyVUr3eh2gneWg4FRx5MwKopQ2e qkARJagGdstKndTXwi8UcW4M6M1gz1upvZCO487JR2PqRMC4qAVDQYsYBuV+W97wqUG9dUXMeed cLyI/2F2k7LjuzZ58+Kzre6s6xxwx0= X-Received: by 2002:a05:622a:a08:b0:516:d943:175f with SMTP id d75a77b69052e-51795c3dea1mr204571121cf.52.1780921331814; Mon, 08 Jun 2026 05:22:11 -0700 (PDT) Received: from server0 (c-68-48-65-54.hsd1.mi.comcast.net. [68.48.65.54]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-517af149fa5sm46086911cf.3.2026.06.08.05.22.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Jun 2026 05:22:11 -0700 (PDT) From: Michael Bommarito To: Jon Maloy , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Ying Xue , netdev@vger.kernel.org, tipc-discussion@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: [PATCH net v3 1/3] tipc: require net admin for TIPCv2 netlink mutators Date: Mon, 8 Jun 2026 08:22:04 -0400 Message-ID: <20260608122206.458290-2-michael.bommarito@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260608122206.458290-1-michael.bommarito@gmail.com> References: <20260608122206.458290-1-michael.bommarito@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7bit TIPCv2 registers mutating generic-netlink operations without admin permission flags. Generic netlink only checks CAP_NET_ADMIN when an operation sets GENL_ADMIN_PERM or GENL_UNS_ADMIN_PERM, so a local unprivileged process can currently change TIPC state through commands such as TIPC_NL_NET_SET, TIPC_NL_KEY_SET, TIPC_NL_KEY_FLUSH, and bearer enable/disable. The legacy TIPC netlink API already checks netlink_net_capable(..., CAP_NET_ADMIN) for administrative commands. Give the TIPCv2 mutators the equivalent generic-netlink gate. Use GENL_UNS_ADMIN_PERM for network-namespace scoped operations and GENL_ADMIN_PERM for TIPC_NL_MEDIA_SET, which updates the shared media defaults rather than state owned only by the target network namespace. A QEMU/KASAN repro run as uid/gid 65534 with zero effective capabilities previously succeeded in changing the network id and node identity, setting and flushing key material, and enabling/disabling a UDP bearer. With this patch applied the same operations fail with -EPERM. Fixes: 0655f6a8635b ("tipc: add bearer disable/enable to new netlink api") Link: https://lore.kernel.org/all/20260604163102.2658553-1-dominik.czarnota@trailofbits.com/ Assisted-by: Codex:gpt-5-5-xhigh Signed-off-by: Michael Bommarito --- v2: - Use GENL_ADMIN_PERM for TIPC_NL_MEDIA_SET because it updates global media defaults, while keeping GENL_UNS_ADMIN_PERM for netns-scoped mutators. net/tipc/netlink.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c index 1a9a5bdaccf4f..5bbe134284acc 100644 --- a/net/tipc/netlink.c +++ b/net/tipc/netlink.c @@ -152,11 +152,13 @@ static const struct genl_ops tipc_genl_v2_ops[] = { { .cmd = TIPC_NL_BEARER_DISABLE, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .flags = GENL_UNS_ADMIN_PERM, .doit = tipc_nl_bearer_disable, }, { .cmd = TIPC_NL_BEARER_ENABLE, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .flags = GENL_UNS_ADMIN_PERM, .doit = tipc_nl_bearer_enable, }, { @@ -168,11 +170,13 @@ static const struct genl_ops tipc_genl_v2_ops[] = { { .cmd = TIPC_NL_BEARER_ADD, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .flags = GENL_UNS_ADMIN_PERM, .doit = tipc_nl_bearer_add, }, { .cmd = TIPC_NL_BEARER_SET, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .flags = GENL_UNS_ADMIN_PERM, .doit = tipc_nl_bearer_set, }, { @@ -197,11 +201,13 @@ static const struct genl_ops tipc_genl_v2_ops[] = { { .cmd = TIPC_NL_LINK_SET, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .flags = GENL_UNS_ADMIN_PERM, .doit = tipc_nl_node_set_link, }, { .cmd = TIPC_NL_LINK_RESET_STATS, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .flags = GENL_UNS_ADMIN_PERM, .doit = tipc_nl_node_reset_link_stats, }, { @@ -213,6 +219,7 @@ static const struct genl_ops tipc_genl_v2_ops[] = { { .cmd = TIPC_NL_MEDIA_SET, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .flags = GENL_ADMIN_PERM, .doit = tipc_nl_media_set, }, { @@ -228,6 +235,7 @@ static const struct genl_ops tipc_genl_v2_ops[] = { { .cmd = TIPC_NL_NET_SET, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .flags = GENL_UNS_ADMIN_PERM, .doit = tipc_nl_net_set, }, { @@ -238,6 +246,7 @@ static const struct genl_ops tipc_genl_v2_ops[] = { { .cmd = TIPC_NL_MON_SET, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .flags = GENL_UNS_ADMIN_PERM, .doit = tipc_nl_node_set_monitor, }, { @@ -255,6 +264,7 @@ static const struct genl_ops tipc_genl_v2_ops[] = { { .cmd = TIPC_NL_PEER_REMOVE, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .flags = GENL_UNS_ADMIN_PERM, .doit = tipc_nl_peer_rm, }, #ifdef CONFIG_TIPC_MEDIA_UDP @@ -269,11 +279,13 @@ static const struct genl_ops tipc_genl_v2_ops[] = { { .cmd = TIPC_NL_KEY_SET, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .flags = GENL_UNS_ADMIN_PERM, .doit = tipc_nl_node_set_key, }, { .cmd = TIPC_NL_KEY_FLUSH, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .flags = GENL_UNS_ADMIN_PERM, .doit = tipc_nl_node_flush_key, }, #endif -- 2.53.0