This is a note to let you know that I've just added the patch titled
Bluetooth: bnep: fix possible might sleep error in bnep_session
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bluetooth-bnep-fix-possible-might-sleep-error-in-bnep_session.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 25717382c1dd0ddced2059053e3ca5088665f7a5 Mon Sep 17 00:00:00 2001
From: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
Date: Tue, 27 Jun 2017 17:34:42 +0800
Subject: Bluetooth: bnep: fix possible might sleep error in bnep_session
From: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
commit 25717382c1dd0ddced2059053e3ca5088665f7a5 upstream.
It looks like bnep_session has same pattern as the issue reported in
old rfcomm:
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
if (condition)
break;
// may call might_sleep here
schedule();
}
__set_current_state(TASK_RUNNING);
Which fixed at:
dfb2fae Bluetooth: Fix nested sleeps
So let's fix it at the same way, also follow the suggestion of:
https://lwn.net/Articles/628628/
Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Reviewed-by: AL Yu-Chen Cho <acho@xxxxxxxx>
Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Cc: Jiri Slaby <jslaby@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/bluetooth/bnep/core.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
--- a/net/bluetooth/bnep/core.c
+++ b/net/bluetooth/bnep/core.c
@@ -484,16 +484,16 @@ static int bnep_session(void *arg)
struct net_device *dev = s->dev;
struct sock *sk = s->sock->sk;
struct sk_buff *skb;
- wait_queue_t wait;
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
BT_DBG("");
set_user_nice(current, -15);
- init_waitqueue_entry(&wait, current);
add_wait_queue(sk_sleep(sk), &wait);
while (1) {
- set_current_state(TASK_INTERRUPTIBLE);
+ /* Ensure session->terminate is updated */
+ smp_mb__before_atomic();
if (atomic_read(&s->terminate))
break;
@@ -515,9 +515,8 @@ static int bnep_session(void *arg)
break;
netif_wake_queue(dev);
- schedule();
+ wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
}
- __set_current_state(TASK_RUNNING);
remove_wait_queue(sk_sleep(sk), &wait);
/* Cleanup session */
@@ -663,7 +662,7 @@ int bnep_del_connection(struct bnep_conn
s = __bnep_get_session(req->dst);
if (s) {
atomic_inc(&s->terminate);
- wake_up_process(s->task);
+ wake_up_interruptible(sk_sleep(s->sock->sk));
} else
err = -ENOENT;
Patches currently in stable-queue which might be from jeffy.chen@xxxxxxxxxxxxxx are
queue-4.4/bluetooth-cmtp-fix-possible-might-sleep-error-in-cmtp_session.patch
queue-4.4/bluetooth-hidp-fix-possible-might-sleep-error-in-hidp_session_thread.patch
queue-4.4/bluetooth-bnep-fix-possible-might-sleep-error-in-bnep_session.patch