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=1794063014; b=JebGcsFKnGyI5mj5gafInR6erafdfZJk1DG87DIFvM602+rHLfpXvCbtX84qfUYPfKc9 RpNqjOEPr+vyCDsRGSrBH8Nt1iBVllfMFG02anJlWfjmJearb+LTt7Lle+hJnxIIoRLZz BPGnyw5naA7J4bSAgK/hr/3unp7YtzFxhJrcJDZ7rjkSlTzIVov1lLkv6OsFCQo6V14dT Y7GzgPauJqTKZI4JkmGu4CnlEhF5M9JcVZAPoLln3fWEeDHc6Z7ecuv53NW9MpfcTVOiO AQLOCl4jjp0JtYKAqnvZ41B2BTJ6jEOGH74AuJEDDE1QfEdpDD8JJhi1ztVF01Vg2dQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794063014; 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=VK72/8ueYghPhD5K+T/8HC65OJm993N8CLLGV/GnG+k=; b=La3wqRHk2b0lQ+KWXG8hC2H+sEMSyIlRvP22B8V2Zp0Se9fQSJG1K/2m8cE9dmWCw8cX vE+QToOK1Qd7KRZt5/3fZi5cLI2yfA5PEOdoKh+6rOBinNpn/+xwm1y008TwgA3ScMUUM NP9d/g/3tVQ2lRZbQewuI+dO5Bzn4zID4K2gIGKk5kPDmZ8rlpH/hFT+kiM6PncbwM6uJ 7MABc2tdZC6Jh+Nd5CD0cL714DVIVzOPMk/xSmr9dxaDfy3lfaQxiI1PGABV4Vms/Z9Cc qGb2La2JN1I4KhsuncpDcnnzsK7PxMKLKhO4IqBwbTZa8rHDDJTPCrInzoZmjmRSQCg== 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=AWJuWT6X; 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 7EC18606D801; Sat, 7 Nov 2026 14:50:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=AWJuWT6X Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A4E01F008A1; Sat, 7 Nov 2026 14:50:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794063014; bh=VK72/8ueYghPhD5K+T/8HC65OJm993N8CLLGV/GnG+k=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=AWJuWT6XfuczHBdvq+Pj7NxOUhIuZp7YTymKIhq0nS7X+whumXBFUmWxu2+saiy8d irvONZ+JGzGDMROC4edST+r4p3B98u22AyLzuxU6HEgE3cEgrRC6GATQK+P7kYKbQo qD/bLyQaSxEEGZSFNo0ZzpSEaE+VD4VLNW/V0aes= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Runyu Xiao , Takashi Iwai , Sasha Levin Subject: [PATCH 6.18 265/869] ALSA: mpu401: shut down timer before freeing MPU Date: Sat, 7 Nov 2026 08:49:07 -0500 Message-ID: <20261107134900.709501223@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134852.069646174@linuxfoundation.org> References: <20261107134852.069646174@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Runyu Xiao [ Upstream commit 9332af5220d42341bb1446a62c545c0518e990ef ] When an MPU401 interface has no usable IRQ, the driver polls raw-MIDI input and output with a timer. During raw-MIDI teardown, the timer callback can already be running when snd_mpu401_uart_remove_timer() clears the last mode bit and calls timer_delete(). That API neither waits for a running callback nor prevents it from rearming the timer, and free_irq() does not synchronize timer callbacks. snd_mpu401_uart_free() can therefore release mpu while the timer callback still uses it. Initialize the timer once when the MPU object is created and only rearm it while a timer mode is active. Shut it down synchronously after freeing the IRQ so an in-flight callback completes before mpu and its resources are released. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Runyu Xiao Link: https://patch.msgid.link/20260927093809.681726-1-runyu.xiao@seu.edu.cn Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/drivers/mpu401/mpu401_uart.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/sound/drivers/mpu401/mpu401_uart.c b/sound/drivers/mpu401/mpu401_uart.c index 4af89822bf32b..94213c1ff1700 100644 --- a/sound/drivers/mpu401/mpu401_uart.c +++ b/sound/drivers/mpu401/mpu401_uart.c @@ -155,20 +155,20 @@ static void snd_mpu401_uart_timer(struct timer_list *t) scoped_guard(spinlock_irqsave, &mpu->timer_lock) { /*mpu->mode |= MPU401_MODE_TIMER;*/ - mod_timer(&mpu->timer, 1 + jiffies); + if (mpu->timer_invoked) + mod_timer(&mpu->timer, 1 + jiffies); } if (mpu->rmidi) _snd_mpu401_uart_interrupt(mpu); } /* - * initialize the timer callback if not programmed yet + * arm the timer if it is not already active */ static void snd_mpu401_uart_add_timer (struct snd_mpu401 *mpu, int input) { guard(spinlock_irqsave)(&mpu->timer_lock); if (mpu->timer_invoked == 0) { - timer_setup(&mpu->timer, snd_mpu401_uart_timer, 0); mod_timer(&mpu->timer, 1 + jiffies); } mpu->timer_invoked |= input ? MPU401_MODE_INPUT_TIMER : @@ -474,6 +474,7 @@ static void snd_mpu401_uart_free(struct snd_rawmidi *rmidi) struct snd_mpu401 *mpu = rmidi->private_data; if (mpu->irq >= 0) free_irq(mpu->irq, (void *) mpu); + timer_shutdown_sync(&mpu->timer); release_and_free_resource(mpu->res); kfree(mpu); } @@ -528,6 +529,7 @@ int snd_mpu401_uart_new(struct snd_card *card, int device, spin_lock_init(&mpu->input_lock); spin_lock_init(&mpu->output_lock); spin_lock_init(&mpu->timer_lock); + timer_setup(&mpu->timer, snd_mpu401_uart_timer, 0); mpu->hardware = hardware; mpu->irq = -1; mpu->rmidi = rmidi; -- 2.53.0