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=1793213030; b=VS8VDKUWOuc9qkHTazSjrP20JnR1oaA8UbbkrB6hwdIXckF2XXTtm+65r7Lp3doBkYWF Hor5c4TjA5zwnQkQPdzU6CJdfw1F/xzhXfIRW6uxmXgSNm3Exn3FnFqHJALh8uJbcuNwL mFYNKqt3BIl6QvAzWMj89o6cSclNgZFZ0a7xLYRx/mk7ZuN+TzuyOckdXyarcubUOgCqY 7/jnq4oyLl9yw7EcUMan9lh/O7lDF3JsJASNB5Q2z+Za6JjOjOhRXNGfZehU6W2zDOyqu b2LlfXRzluenU35lfaYue7s4cWKMP2otHg+aL0vHvll5e0Q2z45gO+umFEMlKNmkvmw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793213030; 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=Y4SyKokpmi/ajw1g8FTqbQzJS8UBZYEQAUBljsB0y+Q=; b=wKgcMpjtZs58HA5oYuJCJLngzZJ41XAqPS7MNUEd7maylkEk7tPcry2EEUVMxAy+JISF TWX0PKddTgegfgRKlgrM7BCEI5KOj730fbqWrQVSQiZnecF/gDegUtsPFttkykBIBIGVy PTwFwsExWofsm6i9aSvk4ie6LDHKwqCfPwR1Ea1TZCI4MXLikQBZPlDG+VeGLoViIQBL1 FgF8/ry+Bxmk6Q40e8SdiNgHKu86r4UjeUahY4WmEkY0kAkeu8ba1D9L8Ubp+8/CsT1vd 8LkTBZ1jvSxBeoySPC6n0v19pEyHDlAILLBiwHc4WvzIiV1+OWtXNyuWQXg0sQ5q9Hg== 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=NgZVulaU; 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 342DD606A322; Wed, 28 Oct 2026 18:43:50 +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=NgZVulaU Received: by smtp.kernel.org (Postfix) with ESMTPSA id 878441F01825; Wed, 28 Oct 2026 18:43:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793213030; bh=Y4SyKokpmi/ajw1g8FTqbQzJS8UBZYEQAUBljsB0y+Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NgZVulaUYa83xJcYh1X0nx+vgOy35rWs5GJMeBNw+LD7M/Y9wVB1ZoossQ/MOxLX0 FSjwbrvhQUjqt7wjdERE9DjIb2d5nE5BMYxokZZwQQVKPmMq2LmQmJiwfpO3xQ+8pc 4dzfRhMm0nAeFPNIJMYkHT0kJtV2Dy7+/lRl+D88= 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 6.1 0362/1887] serial: imx: serialize imx_uart_ports[] lifetime Date: Wed, 28 Oct 2026 17:40:58 +0100 Message-ID: <20261028170507.470178349@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170459.200466217@linuxfoundation.org> References: <20261028170459.200466217@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 6.1-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 @@ -2037,6 +2038,9 @@ 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) { @@ -2522,11 +2526,19 @@ 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); @@ -2538,7 +2550,9 @@ 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)