From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793830867; b=IgnBPu7UKgjVQOJu7CQSeWRO25J6WUQNgzOK7pYensbDLUaqLszvoL2hGTTxoH4NJHzu sn6dOuBoLDKvfZALBhKcEG4ErM1LPb5h7uBJ1EcT+ZwFB2i387e1/jE6g8JuWD533tC5p sBLrAmRDIMJL9itWiIwMuBkXbHwzpuTp/b2A8voUa6JsuGw3liCcNguAjWpHP63T9OKVN dzXRlCEws0I6p8V88EYZ2mLsEkFEhzGbYkubeb0rVkU+e0+UFGnAbkK9DpuDcXfehYhaK UlFmuwC8vfAc13Ietcid5cEWjptEp92KGQmlvXrNaYPsyWTSVdD3JqgA1rcxKN7liUA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793830867; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=JKowdcXLg8Fknoo5OSUzX3H7QeLBqyD9eASZcp7OhkE=; b=tHpUlII+WNRTwX3arHD06yc9waaEPZMj72tRQBYp9kHjTDsH5/8KBBkwJ9CeF+Kz7CKC GomGeJtHtkzDciqB09Le19RDcNiiDp0FJpjgqnMHDnGVwY3sOV5hQtZmhylZ9TkkOkxN1 D23TTCoYT2t01kkD9f/YakIfLsnfiyQO/h5yUTj9RUW9xHxlxxEhdh5KtmP/AhxvX0aJ4 oG+oGoQHSjARb/h2hUXBcFYYj40XWA3QEJkolDLFbmVqvBcJup3KU/fcryLjthHF4HR6o +lujlpmUfLfyHg61UPnCxiqWl41pwOy59hmaQ6s2bWZ2Y9NUeePeUivC/VnHpIRMDsA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=kuihESFt; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 67738606E80C; Wed, 4 Nov 2026 22:21:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=kuihESFt Received: by smtp.kernel.org (Postfix) with ESMTPSA id F35C31F00A15; Wed, 4 Nov 2026 22:21:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793830867; bh=JKowdcXLg8Fknoo5OSUzX3H7QeLBqyD9eASZcp7OhkE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=kuihESFt37/Ya5GTxKFdvwt1wGpyXEY9szaoUvBhNCX2FElFFpknWyAaSHDOaB4VV 6vIFJqGq7KyUwqEFE+rhn4jW3AHzKWbN74yLZfRbYmiAexFD0LytMW8qXCtvaPFOH7 B/5glnXckVm9fBXqoya6KFKYFreYDrRd5WOVxzwU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Pengpeng Hou , Helge Deller , Sasha Levin Subject: [PATCH 6.18 0369/1005] fbdev: udlfb: validate vendor descriptor items Date: Wed, 4 Nov 2026 16:01:42 -0500 Message-ID: <20261104211054.424069880@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211043.516122098@linuxfoundation.org> References: <20261104211043.516122098@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pengpeng Hou [ Upstream commit 3cc2fad376ac7360b4518277aa923752624db59c ] dlfb_parse_vendor_descriptor() walks key-length-value items inside the DisplayLink vendor descriptor. Require each item to contain its key, length and declared value bytes before reading item-specific fields such as max_area. Signed-off-by: Pengpeng Hou Signed-off-by: Helge Deller Signed-off-by: Sasha Levin --- drivers/video/fbdev/udlfb.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c index 70ff38f35096a..1c82ee6984c8d 100644 --- a/drivers/video/fbdev/udlfb.c +++ b/drivers/video/fbdev/udlfb.c @@ -1586,19 +1586,29 @@ static int dlfb_parse_vendor_descriptor(struct dlfb_data *dlfb, desc += 5; /* the fixed header we've already parsed */ while (desc < desc_end) { + char *value; u8 length; u16 key; - key = *desc++; - key |= (u16)*desc++ << 8; + if (desc_end - desc < sizeof(key) + sizeof(length)) + goto unrecognized; + + key = get_unaligned_le16(desc); + desc += sizeof(key); length = *desc++; + if (length > desc_end - desc) + goto unrecognized; + + value = desc; switch (key) { case 0x0200: { /* max_area */ - u32 max_area = *desc++; - max_area |= (u32)*desc++ << 8; - max_area |= (u32)*desc++ << 16; - max_area |= (u32)*desc++ << 24; + u32 max_area; + + if (length < sizeof(max_area)) + goto unrecognized; + + max_area = get_unaligned_le32(value); dev_warn(&intf->dev, "DL chip limited to %d pixel modes\n", max_area); -- 2.53.0