From: Esben Haabendal <esben@geanix.com> mainline inclusion from mainline-v6.10-rc1 commit e533e4c62e9993e62e947ae9bbec34e4c7ae81c2 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAD0R6 CVE: CVE-2024-40967 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- By waiting at most 1 second for USR2_TXDC to be set, we avoid a potential deadlock. In case of the timeout, there is not much we can do, so we simply ignore the transmitter state and optimistically try to continue. Signed-off-by: Esben Haabendal <esben@geanix.com> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Link: https://lore.kernel.org/r/919647898c337a46604edcabaf13d42d80c0915d.171283761... Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Conflicts: drivers/tty/serial/imx.c [Fix context conflicts] Signed-off-by: Felix Fu <fuzhen5@huawei.com> --- drivers/tty/serial/imx.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 2eca7b065c0a..863dab7e3cf2 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -27,6 +27,7 @@ #include <linux/of.h> #include <linux/of_device.h> #include <linux/io.h> +#include <linux/iopoll.h> #include <linux/dma-mapping.h> #include <asm/irq.h> @@ -2006,7 +2007,7 @@ imx_uart_console_write(struct console *co, const char *s, unsigned int count) { struct imx_port *sport = imx_uart_ports[co->index]; struct imx_port_ucrs old_ucr; - unsigned int ucr1; + unsigned int ucr1, usr2; unsigned long flags = 0; int locked = 1; @@ -2038,8 +2039,8 @@ imx_uart_console_write(struct console *co, const char *s, unsigned int count) * Finally, wait for transmitter to become empty * and restore UCR1/2/3 */ - while (!(imx_uart_readl(sport, USR2) & USR2_TXDC)); - + read_poll_timeout_atomic(imx_uart_readl, usr2, usr2 & USR2_TXDC, + 0, USEC_PER_SEC, false, sport, USR2); imx_uart_ucrs_restore(sport, &old_ucr); if (locked) -- 2.34.1