From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5360A412C11 for ; Thu, 3 Sep 2026 12:54:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788440092; cv=none; b=X4yoPVWDNNHJoQSL/9MF5ENcBB+oDtaihpAKCA4V7O7f816bMjSz+8FkyImYZ2KhnwubjLHE25p6dG19tpEMhVkXZDmaP54EksSNVzq81xvKnDsg4tOOkKMj8Qpr/iDvinvacd9WUM0YjNCSzGyKDskNUJyJbG4eUBqmwpWrpzU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788440092; c=relaxed/simple; bh=4Qnuwh8qJ9xxewXE4b4+QkEZUdSzFKXNTdWLgf7OmuQ=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=nLDc+GoX84GO8W4YfOrB5oR9VmsB4emie82h1PdjO1HH0lJha/MPe+6hKvP484RNaic7dRiGkOJYTn9oYYOS55iABl3i31brhwGDf6Dc+Gjl85HQBT9kq9Y04HdvSZAD4o2nh1/C8QucFyb4i9tguFfmlaCjb1TwF5rfKQLCFgU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OSjm5hC2; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="OSjm5hC2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B00361F000E9; Thu, 3 Sep 2026 12:54:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788440091; bh=wnZpLloYfMTgOjoCRz7eG18QlFiPfgMmpjWMSBZJE+s=; h=Subject:To:Cc:From:Date; b=OSjm5hC2Z4jNRIRqpzvi5D77wDpYqlINQW577aU5zg9H8gndtjcjTRB6xhLJrgVa3 LfxukRg6wzThK9NrfA1xXWye3nxocN7jkGinXob/jfMHdx4kyhOT1DySMwo9wmuOPx 0bBwx+xBnFLmP/P+ikbvBfX9EiQCb9e7YTjcQcLU= Subject: FAILED: patch "[PATCH] serial: imx: serialize imx_uart_ports[] lifetime" failed to apply to 5.15-stable tree To: kmehltretter@gmail.com,Frank.Li@nxp.com,gregkh@linuxfoundation.org,sashiko-bot@kernel.org Cc: From: Date: Thu, 03 Sep 2026 14:38:33 +0200 Message-ID: <2026090333-scared-direness-4881@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 8b0b29fdcb47907ae0296b8fe829e918e05e300f # git commit -s git send-email --to '' --in-reply-to '2026090333-scared-direness-4881@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 8b0b29fdcb47907ae0296b8fe829e918e05e300f Mon Sep 17 00:00:00 2001 From: Karl Mehltretter Date: Fri, 31 Jul 2026 20:18:44 +0200 Subject: [PATCH] serial: imx: serialize imx_uart_ports[] lifetime imx_uart_probe() publishes its devm-allocated port in imx_uart_ports[] before uart_add_one_port() because console setup uses the table. The entry is not cleared when adding the port fails or after removal, leaving a dangling pointer. A sibling probe can register the shared console through that stale entry. This was reproduced under KASAN on QEMU mcimx6ul-evk by unbinding a sibling UART, unbinding the console UART and rebinding the sibling. Keep the entry valid through uart_remove_one_port(), then clear it. Protect port addition and removal together with their table updates so sibling operations cannot interleave. Reject an occupied slot rather than clobbering an active port during a duplicate-line probe. Fixes: dbff4e9ea2e8 ("IMX UART: remove statically initialized tables") Fixes: 9f322ad064f9 ("imx: serial: handle initialisation failure correctly") Reported-by: Sashiko Link: https://lore.kernel.org/all/20260719162850.043B41F000E9@smtp.kernel.org Link: https://lore.kernel.org/all/20260719222501.CB4CB1F000E9@smtp.kernel.org Cc: stable@vger.kernel.org Assisted-by: Claude:claude-fable-5 Signed-off-by: Karl Mehltretter Reviewed-by: Frank Li Link: https://patch.msgid.link/20260731181844.11330-6-kmehltretter@gmail.com Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 95fdb60e06a7..513dbe95f7e9 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -2080,6 +2081,9 @@ static const struct uart_ops imx_uart_pops = { static struct imx_port *imx_uart_ports[UART_NR]; +/* Held across uart_add/remove_one_port(); console callbacks must not take it. */ +static DEFINE_MUTEX(imx_uart_ports_lock); + #if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE) static void imx_uart_console_putchar(struct uart_port *port, unsigned char ch) { @@ -2621,11 +2625,19 @@ static int imx_uart_probe(struct platform_device *pdev) goto err_clk; } - imx_uart_ports[sport->port.line] = sport; - platform_set_drvdata(pdev, sport); - ret = uart_add_one_port(&imx_uart_uart_driver, &sport->port); + scoped_guard(mutex, &imx_uart_ports_lock) { + if (imx_uart_ports[sport->port.line]) { + ret = -EBUSY; + } else { + imx_uart_ports[sport->port.line] = sport; + ret = uart_add_one_port(&imx_uart_uart_driver, + &sport->port); + if (ret) + imx_uart_ports[sport->port.line] = NULL; + } + } err_clk: clk_disable_unprepare(sport->clk_ipg); @@ -2637,7 +2649,9 @@ static void imx_uart_remove(struct platform_device *pdev) { struct imx_port *sport = platform_get_drvdata(pdev); + guard(mutex)(&imx_uart_ports_lock); uart_remove_one_port(&imx_uart_uart_driver, &sport->port); + imx_uart_ports[sport->port.line] = NULL; } static void imx_uart_restore_context(struct imx_port *sport)