This is a note to let you know that I've just added the patch titled fsl_lpuart: Don't enable interrupts too early to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: fsl_lpuart-don-t-enable-interrupts-too-early.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 401fb66a355eb0f22096cf26864324f8e63c7d78 Mon Sep 17 00:00:00 2001 From: Indan Zupancic <Indan.Zupancic@xxxxxxxxxxxx> Date: Thu, 5 May 2022 13:47:50 +0200 Subject: fsl_lpuart: Don't enable interrupts too early From: Indan Zupancic <Indan.Zupancic@xxxxxxxxxxxx> commit 401fb66a355eb0f22096cf26864324f8e63c7d78 upstream. If an irq is pending when devm_request_irq() is called, the irq handler will cause a NULL pointer access because initialisation is not done yet. Fixes: 9d7ee0e28da59 ("tty: serial: lpuart: avoid report NULL interrupt") Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Indan Zupancic <Indan.Zupancic@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220505114750.45423-1-Indan.Zupancic@xxxxxxxxxxxx [5.10 did not have lpuart_global_reset or anything after uart_add_one_port(), so add the remove call in cleanup manually] Signed-off-by: Dominique Martinet <dominique.martinet@xxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/fsl_lpuart.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -2586,6 +2586,7 @@ static int lpuart_probe(struct platform_ struct device_node *np = pdev->dev.of_node; struct lpuart_port *sport; struct resource *res; + irq_handler_t handler; int ret; sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); @@ -2658,17 +2659,12 @@ static int lpuart_probe(struct platform_ if (lpuart_is_32(sport)) { lpuart_reg.cons = LPUART32_CONSOLE; - ret = devm_request_irq(&pdev->dev, sport->port.irq, lpuart32_int, 0, - DRIVER_NAME, sport); + handler = lpuart32_int; } else { lpuart_reg.cons = LPUART_CONSOLE; - ret = devm_request_irq(&pdev->dev, sport->port.irq, lpuart_int, 0, - DRIVER_NAME, sport); + handler = lpuart_int; } - if (ret) - goto failed_irq_request; - ret = uart_get_rs485_mode(&sport->port); if (ret) goto failed_get_rs485; @@ -2684,11 +2680,17 @@ static int lpuart_probe(struct platform_ if (ret) goto failed_attach_port; + ret = devm_request_irq(&pdev->dev, sport->port.irq, handler, 0, + DRIVER_NAME, sport); + if (ret) + goto failed_irq_request; + return 0; +failed_irq_request: + uart_remove_one_port(&lpuart_reg, &sport->port); failed_get_rs485: failed_attach_port: -failed_irq_request: lpuart_disable_clks(sport); return ret; } Patches currently in stable-queue which might be from Indan.Zupancic@xxxxxxxxxxxx are queue-5.10/fsl_lpuart-don-t-enable-interrupts-too-early.patch