From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pz2-f12.google.com (mail-pz2-f12.google.com [74.125.228.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1BCC039CCE4 for ; Sat, 19 Sep 2026 22:26:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.228.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789856791; cv=none; b=hzUvEF5KixJYasweNgu/9F89sZheT5x6SNVZVSUymFTZNf33GhjdtRW7MVZ8yMeqVVei2Q2H//gen8jbaYdCrh0ChpeV0NoAPj/vNPEwRNQdNOt5jtkclTPYDF9g7cSVq0BHwDgT1jyDWCRdx71dUro6b3kMZnFMgORYTQGzeHo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789856791; c=relaxed/simple; bh=bKmQjDO7xOd0syALACTYy/o5iBLTBBmStjTLuJ58dQQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=MUbssbm5Mxhh2RbPo5jPOL6w9GELNpNUsmK0JMGRlzqI63oljr25pL5SnbuTTyXquaLfLAT8gmQfOdEHqOVHVGNDIK/fz4JYCIrF84rz3jP2yePPhjMbRSS9JrNBJDJKyxlushCxgwW6b0LrwjnVpHKzytx07cB76f9F6c8rwqM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Ee10MDwo; arc=none smtp.client-ip=74.125.228.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Ee10MDwo" Received: by mail-pz2-f12.google.com with SMTP id d2e1a72fcca58-85a4329731cso1448930b3a.3 for ; Sat, 19 Sep 2026 15:26:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1789856789; x=1790461589; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=V9Y/SVxm8MOmqJvVl1qnXFoqmvLC78rd9Cv4PArFdCA=; b=Ee10MDwor725T37Cj10NUKdaLvJofCD+zWGsJp+ns1L7a9/Qx36I5as1qOrDHMZikb Z/UayuZShLR1NWmcJKtGMg6cdBkygWNbtg/kfDI+yGvbbzsM1ikGkcvwHdQKGkS3FU3I z6bBd+7ULRrQJYHbLcDQXorNXFkeuC/zpj2tZpub6lkZXy5wmclbLZt+XZ/5K1Cp8+iL qONmuSZweJYbkmrrfzB/JcinmcCLqFrpLxIrhbqrMpzbIES3aU9lM/KeTv6JqncLcpse Mf/HrHqKqxEuiCo7YnvC1yAfEB43Gu3KZEJbyfn6ca92o6veVUc4L1xNwdBgoVoIM7Tj i20g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789856789; x=1790461589; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=V9Y/SVxm8MOmqJvVl1qnXFoqmvLC78rd9Cv4PArFdCA=; b=GUb4eZ+39T2d4BA6smvKEHqsRijqea7ZyvdbaOrjkyjw/gAKi1qp2U1pP4K82NP5j9 mDUvjBSi5HwSssQzl72Y1BIfclw0RXMxEbx95MqQUZOtj/oNGReo5kcD3hO9UJqjfeG7 p5oKPx1nWMtP+iKbKmtQsPfXpUBlntV6oCd5ARhQYeMmppzKbTm45544YookjXwTu6/Y U9x+fapwSqygiYSPccqejAxIm4ekZN5O61IzWI+p+4qyVmfh1nFLyhihMYRCcF0cvD6c Z7V/nBwpv/BmtnYXPGdiMp1O7U0BOcei6XA5pVf67sZFWREvLRGnSmu5F4zBImC2OAMM Y89A== X-Forwarded-Encrypted: i=1; AKwUvBzR/dQ3HR8vnPH7vDYvrxDEeQ0zmfmo8Ph6E60FcG9G0t3s1JSCfed6soJxlxepfDSZlCIIZ2PpnlCmKgA=@vger.kernel.org X-Gm-Message-State: AFuF++llPtlu47je2Y8vzWLATWEth6j8RLMa4iEUYkik0PmMVyQzUjtr NTBbvHDVUbOVn22Ob8Oc4KKo+fQgNLD7POglJGpFWWUZVm0UK/mpD3DQ X-Gm-Gg: AYBFou3jD4emyfWCVrR26fpn7CX98fMRTMp2RpHnquPuQpHRFpmzsQBYf/CNaT6Bm/r cTiomQEntMaz9gmz/Q/+F9fnTuOhiCoFhtg1/9xEZKxQy0s3L1czpBF/Lye+atQp4IG/XDGDmBX XnwZxK/I4GtNIJNXVFDggjhhszzzxmIje2PJEu2W/+PzJfJCw3V6IVvTN/OCgW30oFhmAqa5LIK tpeTMiKHRH+7UFwhBjUxRxjtCPmi591V/ZN1tVopYxrN+7fO1Y3EgRllYJ31N06u5MsmBmgpIel etegDF5tZnz0cWoTd2UJ4GenA/wBdY5Sis0yMrqe4JsECWu0g2OB2dY+ZV82/1d9/3WeKPOSfWK U+6ZLCJhStUz6nv1KQaYSZn6vkUG5+q5N7RogfDGCFEVXSexm443upSX+PrYvptkTW+aVz2lGcS W6Km4TNbaGz2SpvSG7WotnjXmPVxbKV7E/NQvnnJxoE5cxhtCsvxQsazGDkpDlS5eaG65/3CI0E 6OEnQQGztbCcJX6wypRoqpgQxqh8on4XaAq9rp0Yepg1kxU7Z5rd/A7StoYGBk75yJ1/PcXUiO6 IJtSqumDYQ== X-Received: by 2002:a05:6a00:94d6:b0:857:7317:cff5 with SMTP id d2e1a72fcca58-874decf4e9emr10344836b3a.22.1789856789222; Sat, 19 Sep 2026 15:26:29 -0700 (PDT) Received: from phui-2.c.googlers.com.com (78.123.83.34.bc.googleusercontent.com. [34.83.123.78]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-877a6ae7d71sm1352690b3a.2.2026.09.19.15.26.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 19 Sep 2026 15:26:28 -0700 (PDT) From: Hui Peng To: gregkh@linuxfoundation.org, jirislaby@kernel.org, john.ogness@linutronix.de Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] serial: fix 8250 hash_mutex race and uart_get_baud_rate() divide-by-zero Date: Sat, 19 Sep 2026 22:26:27 +0000 Message-ID: <20260919222627.3797854-1-benquike@gmail.com> X-Mailer: git-send-email 2.55.0.1082.g2b9226bbc0-goog Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Fix two bugs in the serial subsystem: 1. In serial8250_Label / serial_link_irq_chain() and serial_unlink_irq_chain() (drivers/tty/serial/8250/8250_core.c), hold hash_mutex across the entire IRQ list manipulation and request_irq()/free_irq() sequence to prevent racing IRQ chain insertions/removals. 2. In uart_get_baud_rate() and uart_set_info() (drivers/tty/serial/serial_core.c), avoid unsigned overflow in port->uartclk = new_info->baud_base * 16 and ensure the fallback retry in uart_get_baud_rate() terminates cleanly when no baud rate lies in [min, max]. Fixes: ab4382d27412 ("tty: move drivers/serial/ to drivers/tty/serial/") Assisted-by: LLM Signed-off-by: Hui Peng --- diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index b875d394796f..0bc810f285a4 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -134,8 +134,6 @@ static struct irq_info *serial_get_or_create_irq_info(const struct uart_8250_por { struct irq_info *i; - guard(mutex)(&hash_mutex); - hash_for_each_possible(irq_lists, i, node, up->port.irq) if (i->irq == up->port.irq) return i; @@ -156,6 +154,8 @@ static int serial_link_irq_chain(struct uart_8250_port *up) struct irq_info *i; int ret; + guard(mutex)(&hash_mutex); + i = serial_get_or_create_irq_info(up); if (IS_ERR(i)) return PTR_ERR(i); diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 95774b0f1484..4cd4fb0f7ee3 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -501,7 +501,7 @@ uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, break; } - for (try = 0; try < 2; try++) { + for (try = 0; try < 3; try++) { baud = tty_termios_baud_rate(termios); /* @@ -965,7 +965,7 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, } if ((new_info->irq >= irq_get_nr_irqs()) || (new_info->irq < 0) || - (new_info->baud_base < 9600)) + (new_info->baud_base < 9600) || (new_info->baud_base > UINT_MAX / 16)) return -EINVAL; if (change_port || change_irq) {