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 c2b27ef672 ("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: c2b27ef672 ("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.ne.jp
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Tetsuo Handa 2022-08-27 20:36:27 -07:00 committed by Dmitry Torokhov
parent 80b9ebd3e4
commit 98e0121570
3 changed files with 13 additions and 7 deletions

View file

@ -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,

View file

@ -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,

View file

@ -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,