linux-kernel - Re: [PATCH 1/2 v2] HID: magicmouse: Removing report

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20120704184157.GA272@polaris.bitmath.org>
Date:	Wed, 4 Jul 2012 20:41:57 +0200
From:	"Henrik Rydberg" <rydberg@...omail.se>
To:	Daniel Kurtz <djkurtz@...omium.org>
Cc:	Chase Douglas <chase.douglas@...onical.com>,
	Yufeng Shen <miletus@...omium.org>,
	linux-input@...r.kernel.org, Jiri Kosina <jkosina@...e.cz>,
	linux-kernel@...r.kernel.org,
	Andrew de los Reyes <adlr@...omium.org>
Subject: Re: [PATCH 1/2 v2] HID: magicmouse: Removing report_touches switch

> The input events stop coming when I have more than four fingers on the
> pad, but they start again if I remove the excess fingers. As if the
> transport layer chokes on messages longer than some value...

Yep, that's it. On my system, something sets the L2CAP MTU to a
whopping 48 bytes, and the code below, from l2cap_core.c,

	switch (chan->mode) {
	case L2CAP_MODE_BASIC:
		/* If socket recv buffers overflows we drop data here
		 * which is *bad* because L2CAP has to be reliable.
		 * But we don't have any other choice. L2CAP doesn't
		 * provide flow control mechanism. */

		if (chan->imtu < skb->len)
			goto drop;

silently ignores packets larger than that value. Duh.

Henrik
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/