From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f171.google.com (mail-pl1-f171.google.com [209.85.214.171]) (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 436D33783A0 for ; Tue, 7 Jul 2026 02:52:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783392774; cv=none; b=PsE1n9JZFjV4zca24B+O7pYpcNmRqzy08KZ9MQix4RcjsLQ52KpewTawHE7Bm1/w0GnLD9kayl5WV0lUwAmOmz39jz76TpBT1YJKXoQRVkDcJJt2t5qvrcZVQyev+iam87iSVjEsxZHEstKGZuhUtMI1q3h35tb3XCDa6AZkBic= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783392774; c=relaxed/simple; bh=5M2YrcPiptfqbXGkJTbIpEJldIHFNKqIymihIVN/6sE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qbeIFG36pNZ+5VEIhVRBpnfKuqdo6L7nvFE6bev2uM6WJ3LRB62HpEowU3Cqomq7KniiRN2mdQX5H2JQMOaUNMQkCkK/FTVOhX628ld5yPmgIAo1Lfl9lWS7ROHvkdBDa/XcoRJZo+vQTd9JaSJ4fjvx8K612IlktcoDVKpxDTg= 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=aae0lUia; arc=none smtp.client-ip=209.85.214.171 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="aae0lUia" Received: by mail-pl1-f171.google.com with SMTP id d9443c01a7336-2cabc0a1ab6so40401175ad.0 for ; Mon, 06 Jul 2026 19:52:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1783392772; x=1783997572; 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=PoCszZUb0XOemc0ojDDfrmQI7JkvJWihi2/+4QrQwik=; b=aae0lUiah55hRbbWxvvOOgkSQIDA7x/rFoBMQGDhOjz+F2zJr7nsUwUyDTUj3NqH+5 w1kMDNjvtjHB9wRkvIzGMr52/VVOChyjteGuCepI8qb/Fh2oOBUZf0z6+0pEfrmKRhbo Fr/VIuh/DQfKzMxcdvPG35aHfGDwFqS/r9TCJzAmKMXeEl+RrPgi0VbxAiNj8RC9C3hC aN53iNzG7IzMVABc806jQisLxR2V+AIspqlvnqQB4+/+IjfP5Qbr4ivpT2b3lMpi5NeR KAaSZFiu1OPrH/jypIpOJguZMQ2God0gK5VNoQ/0U2jnz9qTm7Te9aPxyF1WjjwLpPrf rEmg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783392772; x=1783997572; 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=PoCszZUb0XOemc0ojDDfrmQI7JkvJWihi2/+4QrQwik=; b=hyyxyxCX4zULsqM/HpsKnru7jr/y9zYlpy+bf/zEjVIbxDNWNhMxZVnwa3MK9Tcq/r uxSAjvSP7J0huqItGTR+zA5g8UsOHmMqy3Qm4bOstLpXWlYTUmtw9Mn+x/5h/Royjnbn llJ7xT7YJorx34bE3IrAltotnORZVLEX0EsgyA1FfXw3b0dnlsDQMki2dbQXqDKQdChk p/kJux+VQfkukgSnC1t0oSb2iEUmqXu92F8UVvq0BzZtkB9hrzPtH2ieFq7F04I/RgWG uZZ1hKbm1btQyGVxT1EXscCsWMHS6MlXipxzSzqOo92BBYH9uFHbCvjfjyX9jisNi8Nu B4Hg== X-Gm-Message-State: AOJu0Yz+eZkJXBm92fTFjTJTOvYnKzsbr55be+YDUbrFmD27OjpGbGPU epesBXWeQq8IQbo5it1LRc0qcj6wlwrxSwOa6EjOTschpvDVJMz7bySl X-Gm-Gg: AfdE7ckUDVztRzH1+IeNJNadF1WM1vsCiqf+v2H7YeriWGZxaRsqga7r40FmNrjUPIv T1aKCKhf8AAcTqhN8lAVRC6BEGSgM4wAbfQHKVOjYT1d0AlIoMw9+vLEDpfdgXXEKmkUrGy3Bks SqIGnWqFZp41Zy++JP1xY2TumoPpW8pPZbLgp3sdHJaOlNmWiRAo2+a/68fnvwWPW3QXwG3jpAx gT7mSHMSA6AxY/y8I73+TuGyBwbJ1L97w7031r1MT1sJn7cXGCsyZPbQQujMPI+7NAe9QYthglI CLA9KAhLRcgDI2EKBZhd5A21i6KQ+NQ4+XIJqVR7VHifXUESIwJAdmoKGWrbO/fTBnKtl0kereX NBGw9QTwU0LzW/Wo9EyUV/bUlTk3B7EPtEkHZk08LvWpIC7rqGBagWlhAp1t50dtV9l7YnPiLOH 70lzr6Gvg03agbkSCL469hoEwupQfg6KYqaScJu9KyEZHJSbQ6izTa X-Received: by 2002:a17:903:b4b:b0:2ca:b1f6:b0c5 with SMTP id d9443c01a7336-2ccbf1a43edmr34606565ad.38.1783392772292; Mon, 06 Jul 2026 19:52:52 -0700 (PDT) Received: from KRHW1CJW23.bytedance.net ([139.177.225.229]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2ccc9d1e914sm3333165ad.50.2026.07.06.19.52.50 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Mon, 06 Jul 2026 19:52:51 -0700 (PDT) From: Zhao Li To: Johannes Berg Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] wifi: cfg80211: validate rx/tx MLME callback frame lengths before access Date: Tue, 7 Jul 2026 10:52:41 +0800 Message-ID: <20260707025241.22223-1-enderaoelyther@gmail.com> X-Mailer: git-send-email 2.50.1 In-Reply-To: <488ed9862d5196b8f5ecf23f037fa6725fbe9a52.camel@sipsolutions.net> References: <20260612185042.66260-4-enderaoelyther@gmail.com> <488ed9862d5196b8f5ecf23f037fa6725fbe9a52.camel@sipsolutions.net> Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Mon, 2026-07-06 at 18:37 +0800, Johannes Berg wrote: > > Side effects of this change: > > - The WARN_ON(len < 2) is replaced by a silent early return, since > > these cfg80211 callbacks can legitimately receive short frames from > > drivers. > > Can they? How? You're right, that wording is wrong; no in-tree caller passes len < 2. mac80211 gates every path well above that (ieee80211_rx_mgmt_auth() at len < 24 + 6, ieee80211_rx_mgmt_deauth()/disassoc() at len < 24 + 2), and the locally built deauth/disassoc frames are always full size. The frames that do reach these callbacks undersized are short relative to their subtype, not shorter than 2 bytes. mwifiex accepts a 4-address ieee80211_hdr plus the 2-byte firmware length prefix. After it strips the prefix and removes addr4, pkt_len can be exactly 24: a bare 3-address management header with no reason-code body. WARN_ON(len < 2) does not fire on that, and cfg80211_process_deauth() then reads u.deauth.reason_code as a two-byte access starting at offset 24, immediately past the 24-byte buffer. So the len >= 2 check only guards the frame_control read; the per-subtype offsetofend() checks are the actual fix. I'll drop the WARN rather than keep it, because these are exported callbacks and a malformed frame from a driver should be dropped silently instead of backtraced. v2 rewrites the commit message to describe the mwifiex path instead of the inaccurate "legitimately receive short frames" claim; no code change. Thanks, Zhao Li