[PATCH net] net: hso: fix TIOCMIWAIT race

[PATCH net] net: hso: fix TIOCMIWAIT race

[Johan Hovold]

The task state must be updated before checking the wakeup condition to
avoid missing a racing modem status update.

Fixes: 542f54823614 ("tty: Modem functions for the HSO driver")
Cc: stable@vger.kernel.org	# 2.6.29
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/net/usb/hso.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index c1aec67688ae..71caa3764b23 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -1547,10 +1547,10 @@ hso_wait_modem_status(struct hso_serial *serial, unsigned long arg)
 	spin_unlock_irq(&serial->serial_lock);
 	add_wait_queue(&tiocmget->waitq, &wait);
 	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
 		spin_lock_irq(&serial->serial_lock);
 		memcpy(&cnow, &tiocmget->icount, sizeof(struct uart_icount));
 		spin_unlock_irq(&serial->serial_lock);
-		set_current_state(TASK_INTERRUPTIBLE);
 		if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
 		    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
 		    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd))) {
-- 
2.55.0

Re: [PATCH net] net: hso: fix TIOCMIWAIT race

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Mon,  7 Sep 2026 08:52:35 +0200 you wrote:
> The task state must be updated before checking the wakeup condition to
> avoid missing a racing modem status update.
> 
> Fixes: 542f54823614 ("tty: Modem functions for the HSO driver")
> Cc: stable@vger.kernel.org	# 2.6.29
> Signed-off-by: Johan Hovold <johan@kernel.org>
> 
> [...]

Here is the summary with links:
  - [net] net: hso: fix TIOCMIWAIT race
    https://git.kernel.org/netdev/net/c/00f9fbc12320

You are awesome, thank you!
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