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 BF1BE3B83E1; Sat, 17 Oct 2026 17:07:15 +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=1792256836; cv=none; b=fnyahSLk8p/eZ/yC7NMeLBM+N5R0Mj6CqRBsqymYFulP+d6PsLJYk97eAAcSpVn11dxIrVVZJWlk+c8z/TEIuMEis8kFYPuR0uuIFxoONrpPNbkU+hMpn1EwfCKCO7DX2dYi0WiRnnms80rC6LNFcTPyENJ/D6Po0Za+KppOXnA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792256836; c=relaxed/simple; bh=TKD1ZE2rmS15wzhAUH8nI3wWnK9oRY0Om3S556EpllQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cPid7N/bQlTVPU7O378T3GKTXsAFgHDM5EW/4DStwU40xxT5TDwGQ4jds0/TsLg32GMjNk3ofe4sn6iA01DrKuedF3S9IuAwinOwrY4u5oygVXcGpkoDFd1rywvVdyTYi5+ql6MuBPAAdtlY1URPDwh/b7Jc1VKWgyZTii5ClkY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=oKALLWkC; 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="oKALLWkC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C6B001F000C4; Sat, 17 Oct 2026 17:07:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792256835; bh=na+2bRxklBpeo7Afzrdjn43PzGDLXEOK5vXF5zfxlCg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=oKALLWkCDenbNCeyg1jEw2lrbsbmTuvCpcpj42g/GnYEjrnGQY1acdGGx9NvxUOPG QksCQ0c6cI/d0ngHJxr4Q+H/Cqnmyd/KZ5/3g3fJ6yVrz7wHse81M/rIkbwEjawIYV tiXMyznoxJ260/sThUHe0egyeov4mpieRNa9dwiw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sashiko , Karl Mehltretter , Frank Li , Sasha Levin Subject: [PATCH 6.6 0367/1674] serial: imx: serialize imx_uart_ports[] lifetime Date: Sat, 17 Oct 2026 17:43:59 +0200 Message-ID: <20261017160440.543430390@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261017160431.119607952@linuxfoundation.org> References: <20261017160431.119607952@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Karl Mehltretter [ Upstream commit 8b0b29fdcb47907ae0296b8fe829e918e05e300f ] 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 Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/imx.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include @@ -2018,6 +2019,9 @@ static const struct uart_ops imx_uart_po 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) { @@ -2490,11 +2494,19 @@ static int imx_uart_probe(struct platfor } } - 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); @@ -2506,7 +2518,9 @@ static void imx_uart_remove(struct platf { 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)