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 508EE3F4DD8; Wed, 20 May 2026 17:14:38 +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=1779297279; cv=none; b=LkkiEdAA4jYkU7rgjGWLIN5DuMgzAGojWd9hn7qNOB3+Ch9Y3MdFGZ45kTYfb34rKKxsqqwYu4OUbP0FnIZ/QCWfWcjxsxevPX1VwHkk+f+5FLNlE808IDDfW0u4gKaW/vi1ojmHL0IcPl/t1L8tNqWgu0+E5fam1BCkW9zUYnI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779297279; c=relaxed/simple; bh=Ao3EtdLE0yYHACkf9SjgRcenSGCyNdEOrePyiRE2GUw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=TSIfrEIEHTa+OYWVXPF2ZOuxP1r8MXo0vmz/dXlgRy96xU7SCEiw+AaUwuLR4VmvALgfLbJqI2p+NBCn0QsTPv2uj5myjRbvWlhtdIPXE+7gpDxXRpy/dwSB+XXG4zjY5enrnCzv3+TKsTE8kaXDphtpDBCCWxc1ztlfYXXz9Fw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=e2OCc0uS; 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="e2OCc0uS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B7B031F000E9; Wed, 20 May 2026 17:14:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779297278; bh=3XCgqMu+VYtSBwDIheu9nt3gPgv+86GO84vupH2EXD0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=e2OCc0uShkurPklguuGXjeQV0RU2hTiRjSktQZ0ndnIgxUxTMTx5RDzWwm53o6kZ9 wRaYKHNUsnZjnyZkXWHZq4tpxVyQE0mkrwKSXVttFIHhKnp32cXkwxLrjg47XbNH15 Do7ogd+K/9qbntDWW7b9Ff0jPd1PrvO0sJuLa8uI= 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 7.0 1091/1146] ALSA: usb-audio: Bound MIDI endpoint descriptor scans Date: Wed, 20 May 2026 18:22:21 +0200 Message-ID: <20260520162212.927544209@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162148.390695140@linuxfoundation.org> References: <20260520162148.390695140@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 7.0-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 @@ -1947,15 +1947,17 @@ 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; }