From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8A033246781; Thu, 20 Aug 2026 16:43:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787244209; cv=none; b=L3cZxJUKGaA26cohAsGA48nDOXiSviNEjsOLc0Vy8wJY8wkmBn1pSUEYR7mbVkzwb2z5QsccwHSOkDGcqVV557s6iVDac1a0JsY2FXzCQ7dm4LAgPTBObDdMDkdvQ1n29PWOXxPAEjnwWtJPcCfbHoY7yC2TpIPp5Ni9JrJW7+E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787244209; c=relaxed/simple; bh=xwd/M4b2T5TQXZv2y1HfMtzAAlR6HwurzkqlWtbNpfE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tV9KZXo1kGh50sJi6PoZYTjouL6PBMtNHYDgWCcZ7CqS/mVbixmZ7kq2pM7Qk/cDh3KAczX4VI466lqpmkrcCjY2UGMX8uaWpJLDrO9hd6givUyHMiwufiRibdiuG3kjcWHEx6uFxSQdUPcGnIGRnyQfwDqhqJiR4yzrna9jDiA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=G5NY0BhG; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="G5NY0BhG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DBDE31F000E9; Thu, 20 Aug 2026 16:43:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787244208; bh=NVpp/TzTZ1kzmw7oHPJAdPrNODmE5jGoW0zbEejDoL0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=G5NY0BhGHMcVYTOlsmKK1QG3LrQAOerpyj+pt10BlBXkIInZCwsUL0xWjIm9CjHb0 O8VdfIIe5ZHu27z8OI8vgSOzh2RcgmbDY8Oc8OdtZb2r4WZs+Av1bHbTKcRFB+9Pqv lB+t6H3bx8BWrtCMyHTNAifdh5T75Nn4beIluPWc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Maoyi Xie , Mika Westerberg , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.10 088/235] net: thunderbolt: Fix frags[] overflow by bounding frame_count Date: Thu, 20 Aug 2026 16:55:24 +0200 Message-ID: <20260820145219.125099916@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260820145216.426568665@linuxfoundation.org> References: <20260820145216.426568665@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maoyi Xie [ Upstream commit 55d9895f89970501fe126d1026b586b04a224c27 ] tbnet_poll() assembles a multi-frame ThunderboltIP packet into one skb. The first frame goes into the skb linear area and every further frame is added as a page fragment. skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, hdr_size, frame_size, TBNET_RX_PAGE_SIZE - hdr_size); A packet of frame_count frames therefore ends up with frame_count - 1 fragments. tbnet_check_frame() only bounds the peer supplied frame_count to TBNET_RING_SIZE / 4 (64), which is far above MAX_SKB_FRAGS (17 by default). A peer that sends a packet of 19 or more small frames pushes nr_frags past MAX_SKB_FRAGS, so skb_add_rx_frag() writes past skb_shinfo()->frags[] and corrupts memory after the shared info. Tighten the start of packet bound to MAX_SKB_FRAGS + 1 so a packet can never produce more fragments than frags[] can hold. This matches the recent skb frags overflow fixes in other receive paths, for example f0813bcd2d9d ("net: wwan: t7xx: fix potential skb->frags overflow in RX path") and 600dc40554dc ("net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()"). Fixes: e69b6c02b4c3 ("net: Add support for networking over Thunderbolt cable") Cc: stable@vger.kernel.org Signed-off-by: Maoyi Xie Acked-by: Mika Westerberg Link: https://patch.msgid.link/178163152194.2486768.14724194232649760778@maoyixie.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/thunderbolt.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/net/thunderbolt.c +++ b/drivers/net/thunderbolt.c @@ -724,8 +724,12 @@ static bool tbnet_check_frame(struct tbn return true; } - /* Start of packet, validate the frame header */ - if (frame_count == 0 || frame_count > TBNET_RING_SIZE / 4) { + /* Start of packet, validate the frame header. tbnet_poll() puts the + * first frame in the skb linear area and every further frame in a page + * fragment, so a packet may not span more than MAX_SKB_FRAGS + 1 frames + * without overflowing skb_shinfo()->frags[]. + */ + if (frame_count == 0 || frame_count > MAX_SKB_FRAGS + 1) { net->stats.rx_length_errors++; return false; }