From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-vs1-f51.google.com (mail-vs1-f51.google.com [209.85.217.51]) (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 A05FD3DD50F for ; Thu, 9 Apr 2026 15:19:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.217.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775747950; cv=none; b=WfNE26ANQ6VNpqxUpnm1rwjjufk5vBJr9WY2aHF8es1ymZtI1pICG+k1bDPhvYi0wXScotNBWfsa8zulAYLaYYaWBCGfKZhnlnigvzRF1XBkrBeHu4l7bT7Xt8xUyArQvzwVNOVuJlRlatBZiyACoM5Mqw3Dx37k/rBBxuNgQEA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775747950; c=relaxed/simple; bh=T/erxDjW9UFZzf7bm2hBpPwN8nVpBgLLyvaiBrM62xU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=XAQqafCbOwNxEnI3G/UN86wcxOAnI1cmJWu+/NAxj2hHK0h+HjE4OMu6axmrEhYjIe5ueOKgZUgBR8wQM5c2zRccukO1+YGlIyCFM2aX40aTrX7mlcXXwNFfOg0ExHxIrcbypj2msqHdsvbXJMk5GBhT44/DSGU8eHxwjltm9N0= 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=HnooKcP8; arc=none smtp.client-ip=209.85.217.51 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="HnooKcP8" Received: by mail-vs1-f51.google.com with SMTP id ada2fe7eead31-605048a9c94so278617137.0 for ; Thu, 09 Apr 2026 08:19:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1775747948; x=1776352748; 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=ht4C6Q0Frr+SWXmDtcQM792Kd3ZqmaPaKjBBDdw6zT0=; b=HnooKcP8Jh6f/JkmAkEhuzSmgCeHeKCjUNtCrPAQ7SbYaFC2OgU1Q6Il4hfjnN4ME4 ht/s4Rw0+2W5Fuf2uKd3O2bF0tl3XDLv0KWvUQLcgKm9++9NxHmgYVMIQtq7C+oP+86J oi4e9BYwiErJki7TE/fouAjZLDo70MTCgtuL9jWCWEmoWBcHX79B5IKAZD45+x/y96yX ka7gaD9pyaUbxver4bl8TT5QgWzZNnE5YUXW2fK4RD19Nc9Ezt2SzfSE/oUDzvfGJwZn xbY5KgX5vhYRPKc9hudluIW/Pvp5s0LogO6fQjmXRJtmYd7yVEMoXPqtMAXBIbRx6vxs DDCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775747948; x=1776352748; 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=ht4C6Q0Frr+SWXmDtcQM792Kd3ZqmaPaKjBBDdw6zT0=; b=oL5I1X28iio9IVsSoIlfYLFINsVyYrra6MCCfPW0KFSK7BNtGUikgJl4FRgm8VrTOI cxSN5prt9fxgFPtKZpa8HEcaQtBCLwkB9hNEMSt3PkhO4S2b++NtPCozYeU1yJzxtZWK nWlUFk6YEerOZR1zNkWPi/ac0+x3XpUCvhErZ5gqSEQJj12QSKOkTC1IYlQ+zzvFl9ME lljMuV8j3WKvSAYMxtohMn51+bNjVsSh4e5fOolz33EBUFsWrgvCnrPwjxdFqvZNHkAB 7VLwSgFIkjWScBtkoWpCa5DRAbW7I6tG0cotYwfQGdNOfdyVwSzznZaPYPxddZqtnawg OvYA== X-Gm-Message-State: AOJu0YykyGHrn7Fo4dGdF1Uo8udRXsNUDy+gGxuPL9fu4id6FgWyIt2O bx+RXco7EaNfcpuGIsPR/r4Z4d0eful9JJTguXaANBUsYlspsYN5p/fALWNbszZCEUyV7A== X-Gm-Gg: AeBDieu5cjwCrysWrSVpl3nptjN55p3rOCNE/SSsbopaXhiiCEKbTJ4CJUqcQ7zGWZx D8mZJBHrgr3e73ZPlIDSKuF+BSC3bxMB1oNBqUeoSlNb+/FvJuxxIpAN6w8Z6hXoBSB23P84NLP GWhALv8yY7+CVmEDke7IF6c1VzsDQ1RvTARzHYEGhP+M07WECRXZ1n8jbRiBXiYr/sWcqZ+LOU2 30iCsGeXvtZWAUxIDuXxoI+ZKT7YfAIT5oCbwAe7Aktw10WaE/zxNGooAq00uCBKuLwyR3V0T82 cTHHWksoTTfVA8Mo6g3umKFE6QHbmThUXOVqCRnH2jysWSUf+opEYPPJCSpkJxh/w+NSg2oaHiK Y1r2BAaKU6Td54dJCnH4QCX+2nE0bTlj09GiFMLK5iAzLIiKLp4J42vcNcXPoYHfuWWjBoPKaPn MK7/g0qIqJvLZe62m0lOGVMSfdN0atvBmXmd3oRRfyOznF2lkmsbh3SWx5nadis7fOD/x2lKTDm R7MXgXKmF1jNt8tr4P+kzmcK6BOaa+OL3BCAFI= X-Received: by 2002:a67:e113:0:b0:5f5:4d9b:bd67 with SMTP id ada2fe7eead31-605a4e20b60mr8913640137.6.1775747948440; Thu, 09 Apr 2026 08:19:08 -0700 (PDT) Received: from TDC4045031631.e0cglfehwr0e5gttmepj3hi3hf.ux.internal.cloudapp.net ([20.63.37.123]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8a5969156d3sm202318526d6.31.2026.04.09.08.19.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Apr 2026 08:19:08 -0700 (PDT) From: Ashutosh Desai To: netdev@vger.kernel.org Cc: Eric Dumazet , linux-hams@vger.kernel.org, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, linux-kernel@vger.kernel.org, Ashutosh Desai Subject: [PATCH v2] rose: fix OOB reads on short CLEAR REQUEST frames. Date: Thu, 9 Apr 2026 15:19:06 +0000 Message-Id: <20260409151906.2218957-1-ashutoshdesai993@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit rose_process_rx_frame() passes skb directly to rose_decode(), which reads skb->data[2] without any prior length check. For CLEAR REQUEST frames the state machines then read skb->data[3] and skb->data[4] as the cause and diagnostic bytes. The original fix checked skb->len after the rose_decode() call, which was wrong for two reasons: rose_decode() already accessed skb->data[2] before the check ran, and skb->len counts bytes across non-linear fragments while skb->data only covers the linear head - so even a passing len check doesn't guarantee the bytes are safe to read directly. Eric Dumazet pointed out that pskb_may_pull() is the right approach here. Add a pskb_may_pull(skb, 3) check before rose_decode() to cover its frame[2] access, and a pskb_may_pull(skb, 5) check afterwards for the CLEAR REQUEST path to cover the cause and diagnostic reads. Suggested-by: Eric Dumazet Signed-off-by: Ashutosh Desai --- net/rose/rose_in.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/net/rose/rose_in.c b/net/rose/rose_in.c index 0276b393f..b9f01a11e 100644 --- a/net/rose/rose_in.c +++ b/net/rose/rose_in.c @@ -269,8 +269,18 @@ int rose_process_rx_frame(struct sock *sk, struct sk_buff *skb) if (rose->state == ROSE_STATE_0) return 0; + if (!pskb_may_pull(skb, 3)) { + kfree_skb(skb); + return 0; + } + frametype = rose_decode(skb, &ns, &nr, &q, &d, &m); + if (frametype == ROSE_CLEAR_REQUEST && !pskb_may_pull(skb, 5)) { + kfree_skb(skb); + return 0; + } + switch (rose->state) { case ROSE_STATE_1: queued = rose_state1_machine(sk, skb, frametype); -- 2.34.1