From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793208923; b=5h4LaBr2Jy5CFzB+oX+Cs+FJDfXkdlVGF9bAK8p5LMaDdQiB2qIsIUEeUtsxQZM2+PK5 tOfff6d8Gng7A6VSh1OPcPaOpKrPOT3PUrUc87CiGVBc9h7NIod2Eu4VS1EADyJ+27NE7 HTBP1FkpcD9LPG4KfAtpHRLdSaxvgv5fSoV134T/p4rqrDdXBWjG1asd0GzNbVwd2tQTT 7h2Iw36baVHnveCTg9wZaoIRC0HhIV1i0/Qdl34E1PSoIZiTRSY9gpk8KfyJXYf1fBfo1 tnY4RRqe7g09NBVLCl2IDr9C5T2ps0mF75fCLoKT4klneRds49/hLgKorbXI6g0iSbg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793208923; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=elrC0wK0GR5a0x1Bt+q6v2tfodOgN3mM79yc9v4vk+w=; b=WQ7d/rvHLCb6LMwD60qgB+6DOtXGe57pZgCtGpGP6fMVhgt8o+g9YzCaqb6pnG9TPIDa 7PXIBsMTJnpaWW2QSlseHfAESUYhwOmmGoen34Pw4McNFG91BaTNACqTnC1UXcTHwK+VK W6CimtjUFMIZLHgUz3q+dlGiRD2TJcW93bamOkS9ZQCK2o+wbnOCE7jPY8HCL0/H902/y RHd7ZBXHC9HndWpH7wZ0dPt1FT6dfUYgPGIjM/Jb2xHMzzMQ4+eG0t0BW5qAmO/SrBPKp vdJVYPsok3ih7iQeCgXoISNcnLBt1rUVO4gatnc8L2b5YbhjQvz+w/uEViGSjgvfbUw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=CqxijWXZ; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4F880606A31D; Wed, 28 Oct 2026 17:35:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=CqxijWXZ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90C751F01825; Wed, 28 Oct 2026 17:35:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793208923; bh=elrC0wK0GR5a0x1Bt+q6v2tfodOgN3mM79yc9v4vk+w=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=CqxijWXZENs8GBNxvlHjah3V4z6lNCvMF1o/EgVqqssWcKxdhhz1/Gla9qUmyC2pi MdSXCSWSpuTaxYJQTY1Gs1vwQLVI/GLgy1+vtX1Yjd111DjkrZ2yTQnm3b1iNYWkgr A3vNUD5xAStgty3Pm0WyKYDzOlkCtHlwKRBbXDbY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, sashiko-bot@kernel.org, stable@kernel.org, Johan Hovold , Sasha Levin Subject: [PATCH 5.10 291/516] serial: fix TIOCMIWAIT race Date: Wed, 28 Oct 2026 17:57:23 +0100 Message-ID: <20261028170010.386766091@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170003.522232767@linuxfoundation.org> References: <20261028170003.522232767@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold [ Upstream commit 40adffec8c0090533dfaa863ced7901b60bbf1dc ] The task state must be updated before checking the wakeup condition to avoid missing a racing modem status update. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: sashiko-bot@kernel.org Link: https://lore.kernel.org/r/20260904115542.E20D11F00A3D@smtp.kernel.org Cc: stable@kernel.org Signed-off-by: Johan Hovold Link: https://patch.msgid.link/20260910130816.642699-4-johan@kernel.org Signed-off-by: Greg Kroah-Hartman [ sashal: adjusted context for spin_lock_irq()/spin_unlock_irq() instead of uart_port_lock_irq()/uart_port_unlock_irq() ] Signed-off-by: Sasha Levin --- drivers/tty/serial/serial_core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 6d7d448d0fbf5..7e4cab742321c 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1240,12 +1240,12 @@ static int uart_wait_modem_status(struct uart_state *state, unsigned long arg) add_wait_queue(&port->delta_msr_wait, &wait); for (;;) { + set_current_state(TASK_INTERRUPTIBLE); + spin_lock_irq(&uport->lock); memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); spin_unlock_irq(&uport->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)) || -- 2.53.0