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 C269130EF7E; Tue, 21 Jul 2026 19:56:24 +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=1784663785; cv=none; b=gf5TyvlIkF7w72ESAxDa/5xDbaycdKMHEvSRujW1Fhg1xC9/JVnHAfqvodMwk5Q2RhV3GIOhcfX0MYpwAflZ7hNrG1R5gOM5tOwfLpOhEIFTEnBsTZgXBYDR1csv4gUcUKW3fVx/bJJxkUWDbxomEp9PZEA4noUMYq+HomaPPZY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784663785; c=relaxed/simple; bh=kom/yImSFT1m7Fdk8GVM7bvO4EEeLMmQBizqPVwpUfE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LmGJ8lZmk1l+MLWFIua7nsF9536nvuU/qzUmfOkucLZvalPksviKpTSMs8G9uck8DdRG1Ror0Br5H/KNLSVuGcm9IGe8mYPf/NVvvsVSThPkxWdaGg6NljCcT5+iXdBUw+ABK2NmVSs7tlBXLbmJUhqx/6bBmrlflZM6MtpBuKU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=h0WWC6sr; 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="h0WWC6sr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 337E91F000E9; Tue, 21 Jul 2026 19:56:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784663784; bh=Fj/B1wzCS80j24fT87fl1wKkOGsLkM33LWJw/yk6xuU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=h0WWC6srdNTKvZmx4e/xH/LL9S4QxbfN3A50L8Zx7oOp1PrZaN79Jqy59wkHEMTvf LrIhz5CNL8vviAme3t5BfAiHiMDQVX7qg5eKiNt7QQGM7+CKIczIKyVjx1NolIo9SH YakC8yUgfZyU10XlWPObBIx/xhwWQW652OeGW6eE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Maoyi Xie , Mika Westerberg , Jakub Kicinski Subject: [PATCH 6.12 0953/1276] net: thunderbolt: Fix frags[] overflow by bounding frame_count Date: Tue, 21 Jul 2026 17:23:16 +0200 Message-ID: <20260721152507.354576166@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152446.065700225@linuxfoundation.org> References: <20260721152446.065700225@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maoyi Xie commit 55d9895f89970501fe126d1026b586b04a224c27 upstream. 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: Greg Kroah-Hartman --- drivers/net/thunderbolt/main.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/net/thunderbolt/main.c +++ b/drivers/net/thunderbolt/main.c @@ -786,8 +786,12 @@ 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; }