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From: Jiri Slaby <jslaby@suse.cz>
To: stable@vger.kernel.org
Cc: David Herrmann <dh.herrmann@gmail.com>,
	Marcel Holtmann <marcel@holtmann.org>,
	Jiri Slaby <jslaby@suse.cz>
Subject: [patch added to the 3.12 stable tree] Bluetooth: hidp: fix device disconnect on idle timeout
Date: Tue,  5 Jan 2016 16:28:34 +0100	[thread overview]
Message-ID: <1452007726-3747-33-git-send-email-jslaby@suse.cz> (raw)
In-Reply-To: <1452007726-3747-1-git-send-email-jslaby@suse.cz>

From: David Herrmann <dh.herrmann@gmail.com>

This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.

===============

commit 660f0fc07d21114549c1862e67e78b1cf0c90c29 upstream.

The HIDP specs define an idle-timeout which automatically disconnects a
device. This has always been implemented in the HIDP layer and forced a
synchronous shutdown of the hidp-scheduler. This works just fine, but
lacks a forced disconnect on the underlying l2cap channels. This has been
broken since:

    commit 5205185d461d5902325e457ca80bd421127b7308
    Author: David Herrmann <dh.herrmann@gmail.com>
    Date:   Sat Apr 6 20:28:47 2013 +0200

        Bluetooth: hidp: remove old session-management

The old session-management always forced an l2cap error on the ctrl/intr
channels when shutting down. The new session-management skips this, as we
don't want to enforce channel policy on the caller. In other words, if
user-space removes an HIDP device, the underlying channels (which are
*owned* and *referenced* by user-space) are still left active. User-space
needs to call shutdown(2) or close(2) to release them.

Unfortunately, this does not work with idle-timeouts. There is no way to
signal user-space that the HIDP layer has been stopped. The API simply
does not support any event-passing except for poll(2). Hence, we restore
old behavior and force EUNATCH on the sockets if the HIDP layer is
disconnected due to idle-timeouts (behavior of explicit disconnects
remains unmodified). User-space can still call

    getsockopt(..., SO_ERROR, ...)

..to retrieve the EUNATCH error and clear sk_err. Hence, the channels can
still be re-used (which nobody does so far, though). Therefore, the API
still supports the new behavior, but with this patch it's also compatible
to the old implicit channel shutdown.

Reported-by: Mark Haun <haunma@keteu.org>
Reported-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 net/bluetooth/hidp/core.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/net/bluetooth/hidp/core.c b/net/bluetooth/hidp/core.c
index bdc35a7a7fee..49637fb491a9 100644
--- a/net/bluetooth/hidp/core.c
+++ b/net/bluetooth/hidp/core.c
@@ -415,6 +415,20 @@ static void hidp_idle_timeout(unsigned long arg)
 {
 	struct hidp_session *session = (struct hidp_session *) arg;
 
+	/* The HIDP user-space API only contains calls to add and remove
+	 * devices. There is no way to forward events of any kind. Therefore,
+	 * we have to forcefully disconnect a device on idle-timeouts. This is
+	 * unfortunate and weird API design, but it is spec-compliant and
+	 * required for backwards-compatibility. Hence, on idle-timeout, we
+	 * signal driver-detach events, so poll() will be woken up with an
+	 * error-condition on both sockets.
+	 */
+
+	session->intr_sock->sk->sk_err = EUNATCH;
+	session->ctrl_sock->sk->sk_err = EUNATCH;
+	wake_up_interruptible(sk_sleep(session->intr_sock->sk));
+	wake_up_interruptible(sk_sleep(session->ctrl_sock->sk));
+
 	hidp_session_terminate(session);
 }
 
-- 
2.6.4


  parent reply	other threads:[~2016-01-05 15:30 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-05 15:28 [patch added to the 3.12 stable tree] ipv6: fix tunnel error handling Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] MIPS: KVM: Fix ASID restoration logic Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] MIPS: KVM: Fix CACHE immediate offset sign extension Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] MIPS: KVM: Uninit VCPU in vcpu_create error path Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] unix: avoid use-after-free in ep_remove_wait_queue Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] packet: do skb_probe_transport_header when we actually have data Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] packet: infer protocol from ethernet header if unset Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] sctp: translate host order to network order when setting a hmacid Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] snmp: Remove duplicate OUTMCAST stat increment Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] net: qmi_wwan: add XS Stick W100-2 from 4G Systems Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] tcp: md5: fix lockdep annotation Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] tcp: initialize tp->copied_seq in case of cross SYN connection Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] net, scm: fix PaX detected msg_controllen overflow in scm_detach_fds Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] net: ipmr: fix static mfc/dev leaks on table destruction Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] net: ip6mr: " Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] broadcom: fix PHY_ID_BCM5481 entry in the id table Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] ipv6: distinguish frag queues by device for multicast and link-local packets Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] ipv6: add complete rcu protection around np->opt Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] net/neighbour: fix crash at dumping device-agnostic proxy entries Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] ipv6: sctp: implement sctp_v6_destroy_sock() Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] Bluetooth: ath3k: Add support of 04ca:300d AR3012 device Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] ARM: 8426/1: dma-mapping: add missing range check in dma_mmap() Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] ARM: 8427/1: dma-mapping: add support for offset parameter " Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] ARM: common: edma: Fix channel parameter for irq callbacks Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] x86/setup: Extend low identity map to cover whole kernel range Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] x86/setup: Fix low identity map for >= 2GB " Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] x86/cpu: Call verify_cpu() after having entered long mode too Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] x86/cpu: Fix SMAP check in PVOPS environments Jiri Slaby
2016-01-05 15:28 ` Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] mac80211: fix driver RSSI event calculations Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] net: mvneta: Fix CPU_MAP registers initialisation Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] mwifiex: fix mwifiex_rdeeprom_read() Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] staging: rtl8712: Add device ID for Sitecom WLA2100 Jiri Slaby
2016-01-05 15:28 ` Jiri Slaby [this message]
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] Bluetooth: ath3k: Add new AR3012 0930:021c id Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] Bluetooth: ath3k: Add support of AR3012 0cf3:817b device Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] can: sja1000: clear interrupts on start Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] arm64: Fix compat register mappings Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] usblp: do not set TASK_INTERRUPTIBLE before lock Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] usb: musb: core: fix order of arguments to ulpi write callback Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] USB: ti_usb_3410_5052: Add Honeywell HGI80 ID Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] USB: serial: option: add support for Novatel MiFi USB620L Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] USB: option: add XS Stick W100-2 from 4G Systems Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] ALSA: usb-audio: add packet size quirk for the Medeli DD305 Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] ALSA: usb-audio: prevent CH345 multiport output SysEx corruption Jiri Slaby
2016-01-05 15:28 ` [patch added to the 3.12 stable tree] ALSA: usb-audio: work around CH345 input " Jiri Slaby

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