The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 98e01215708b6d416345465c09dce2bd4868c67a Mon Sep 17 00:00:00 2001 From: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Date: Sat, 27 Aug 2022 20:36:27 -0700 Subject: [PATCH] Input: iforce - wake up after clearing IFORCE_XMIT_RUNNING flag
syzbot is reporting hung task at __input_unregister_device() [1], for iforce_close() waiting at wait_event_interruptible() with dev->mutex held is blocking input_disconnect_device() from __input_unregister_device().
It seems that the cause is simply that commit c2b27ef672992a20 ("Input: iforce - wait for command completion when closing the device") forgot to call wake_up() after clear_bit().
Fix this problem by introducing a helper that calls clear_bit() followed by wake_up_all().
Reported-by: syzbot syzbot+deb6abc36aad4008f407@syzkaller.appspotmail.com Fixes: c2b27ef672992a20 ("Input: iforce - wait for command completion when closing the device") Tested-by: syzbot syzbot+deb6abc36aad4008f407@syzkaller.appspotmail.com Suggested-by: Fabio M. De Francesco fmdefrancesco@gmail.com Co-developed-by: Hillf Danton hdanton@sina.com Signed-off-by: Hillf Danton hdanton@sina.com Signed-off-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Link: https://lore.kernel.org/r/887021c3-4f13-40ce-c8b9-aa6e09faa3a7@I-love.SAKURA... Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com
diff --git a/drivers/input/joystick/iforce/iforce-serio.c b/drivers/input/joystick/iforce/iforce-serio.c index f95a81b9fac7..2380546d7978 100644 --- a/drivers/input/joystick/iforce/iforce-serio.c +++ b/drivers/input/joystick/iforce/iforce-serio.c @@ -39,7 +39,7 @@ static void iforce_serio_xmit(struct iforce *iforce)
again: if (iforce->xmit.head == iforce->xmit.tail) { - clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags); + iforce_clear_xmit_and_wake(iforce); spin_unlock_irqrestore(&iforce->xmit_lock, flags); return; } @@ -64,7 +64,7 @@ static void iforce_serio_xmit(struct iforce *iforce) if (test_and_clear_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags)) goto again;
- clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags); + iforce_clear_xmit_and_wake(iforce);
spin_unlock_irqrestore(&iforce->xmit_lock, flags); } @@ -169,7 +169,7 @@ static irqreturn_t iforce_serio_irq(struct serio *serio, iforce_serio->cmd_response_len = iforce_serio->len;
/* Signal that command is done */ - wake_up(&iforce->wait); + wake_up_all(&iforce->wait); } else if (likely(iforce->type)) { iforce_process_packet(iforce, iforce_serio->id, iforce_serio->data_in, diff --git a/drivers/input/joystick/iforce/iforce-usb.c b/drivers/input/joystick/iforce/iforce-usb.c index ea58805c480f..cba92bd590a8 100644 --- a/drivers/input/joystick/iforce/iforce-usb.c +++ b/drivers/input/joystick/iforce/iforce-usb.c @@ -30,7 +30,7 @@ static void __iforce_usb_xmit(struct iforce *iforce) spin_lock_irqsave(&iforce->xmit_lock, flags);
if (iforce->xmit.head == iforce->xmit.tail) { - clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags); + iforce_clear_xmit_and_wake(iforce); spin_unlock_irqrestore(&iforce->xmit_lock, flags); return; } @@ -58,9 +58,9 @@ static void __iforce_usb_xmit(struct iforce *iforce) XMIT_INC(iforce->xmit.tail, n);
if ( (n=usb_submit_urb(iforce_usb->out, GFP_ATOMIC)) ) { - clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags); dev_warn(&iforce_usb->intf->dev, "usb_submit_urb failed %d\n", n); + iforce_clear_xmit_and_wake(iforce); }
/* The IFORCE_XMIT_RUNNING bit is not cleared here. That's intended. @@ -175,15 +175,15 @@ static void iforce_usb_out(struct urb *urb) struct iforce *iforce = &iforce_usb->iforce;
if (urb->status) { - clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags); dev_dbg(&iforce_usb->intf->dev, "urb->status %d, exiting\n", urb->status); + iforce_clear_xmit_and_wake(iforce); return; }
__iforce_usb_xmit(iforce);
- wake_up(&iforce->wait); + wake_up_all(&iforce->wait); }
static int iforce_usb_probe(struct usb_interface *intf, diff --git a/drivers/input/joystick/iforce/iforce.h b/drivers/input/joystick/iforce/iforce.h index 6aa761ebbdf7..9ccb9107ccbe 100644 --- a/drivers/input/joystick/iforce/iforce.h +++ b/drivers/input/joystick/iforce/iforce.h @@ -119,6 +119,12 @@ static inline int iforce_get_id_packet(struct iforce *iforce, u8 id, response_data, response_len); }
+static inline void iforce_clear_xmit_and_wake(struct iforce *iforce) +{ + clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags); + wake_up_all(&iforce->wait); +} + /* Public functions */ /* iforce-main.c */ int iforce_init_device(struct device *parent, u16 bustype,