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 DB326403E94; Wed, 20 May 2026 18:49:32 +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=1779302975; cv=none; b=BjPuTYyR1cgi2iPNCOVovkINwy5a8OE9QO2csAgQLAzkcr1C3MHSubpuXc4Lm9hFjCKp2rs/UIfjiNNEDJbyRdMhQia2HQ6pL0wFGoHZifQa/zz766qUSV5jm0DgoBWC8hkZz9Dz/mbD7G3zqFAewY6fXfhGrd5qsf/6+6DqefI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779302975; c=relaxed/simple; bh=Ci9o0ZbaJL1QJEPG17dCMMwFtTUEZgWqORG1tkt+xD0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=r0AKq+cuKYN97tGzIoms79ThPQ5RbS18yBTp4IoynF3l7Nhut4MFXAKpQGyty0WAHp7CocxSNgd3gjbZIU+pHcerJsJRm1tSiHOf8DM0aDf4nHC/GYmtLStW510axcwQOJedhx2utLLDCIhYPQKIN8bBuhIJUibGNzwm0LKwQto= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mVb0Dsmh; 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="mVb0Dsmh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B0E3A1F00893; Wed, 20 May 2026 18:49:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779302972; bh=jQ+14HFEgisjJfJ2XmIHyBmEw+/SjpGsfi15yPr/85M=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=mVb0Dsmhn6mtfSx19WJEiBmcnUUgTMb0dVusgGU9W85xUPwOOd/uahpoBDwZWRAWv cSwKD+c6t5KJJVnztKMS2GHQT9Vb0u63Q+Oxyu8h4ixkZjhlOm9XwW+NBGyZE9BKJs 8Iq3Ikf9O15x3/W9mxRsjQhh4xVI64O4y6tVxMZI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?C=C3=A1ssio=20Gabriel?= , Takashi Iwai Subject: [PATCH 6.6 469/508] ALSA: usb-audio: Bound MIDI endpoint descriptor scans Date: Wed, 20 May 2026 18:24:52 +0200 Message-ID: <20260520162108.759405304@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162058.573354582@linuxfoundation.org> References: <20260520162058.573354582@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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Cássio Gabriel commit d6854daa67be623860f4e1873fd3d3c275aba4ed upstream. snd_usbmidi_get_ms_info() validates the internal MIDIStreaming endpoint descriptor size before using baAssocJackID[], but the descriptor walker can still return a class-specific endpoint descriptor whose bLength exceeds the remaining bytes in the endpoint-extra scan. That leaves later flexible-array reads bounded by bLength, but not by the remaining bytes in the endpoint-extra scan. Stop walking when bLength is zero or extends past the remaining endpoint-extra scan. Fixes: 5c6cd7021a05 ("ALSA: usb-audio: Fix case when USB MIDI interface has more than one extra endpoint descriptor") Cc: stable@vger.kernel.org Signed-off-by: Cássio Gabriel Link: https://patch.msgid.link/20260507-usb-midi-endpoint-scan-bounds-v1-1-329d7348160e@gmail.com Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/midi.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/sound/usb/midi.c +++ b/sound/usb/midi.c @@ -1974,15 +1974,17 @@ static struct usb_ms_endpoint_descriptor while (extralen > 3) { struct usb_ms_endpoint_descriptor *ms_ep = (struct usb_ms_endpoint_descriptor *)extra; + int length = ms_ep->bLength; - if (ms_ep->bLength > 3 && + if (!length || length > extralen) + break; + + if (length > 3 && ms_ep->bDescriptorType == USB_DT_CS_ENDPOINT && ms_ep->bDescriptorSubtype == UAC_MS_GENERAL) return ms_ep; - if (!extra[0]) - break; - extralen -= extra[0]; - extra += extra[0]; + extralen -= length; + extra += length; } return NULL; }