From: Udit Kumar u-kumar1@ti.com

stable inclusion from stable-v5.10.221 commit cb879300669881970eabebe64bd509dbbe42b9de category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAGEP6 CVE: CVE-2024-42095

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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commit 9d141c1e615795eeb93cd35501ad144ee997a826 upstream.

As per Errata i2310[0], Erroneous timeout can be triggered, if this Erroneous interrupt is not cleared then it may leads to storm of interrupts, therefore apply Errata i2310 solution.

[0] https://www.ti.com/lit/pdf/sprz536 page 23

Fixes: b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs") Cc: stable@vger.kernel.org Signed-off-by: Udit Kumar u-kumar1@ti.com Link: https://lore.kernel.org/r/20240619105903.165434-1-u-kumar1@ti.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Felix Fu fuzhen5@huawei.com --- drivers/tty/serial/8250/8250_omap.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 25765ebb756a..955642e90ede 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -164,6 +164,10 @@ static void uart_write(struct omap8250_priv *priv, u32 reg, u32 val) writel(val, priv->membase + (reg << OMAP_UART_REGSHIFT)); }

+/* Timeout low and High */ +#define UART_OMAP_TO_L 0x26 +#define UART_OMAP_TO_H 0x27 + /* * Called on runtime PM resume path from omap8250_restore_regs(), and * omap8250_set_mctrl(). @@ -647,13 +651,24 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id)

/* * On K3 SoCs, it is observed that RX TIMEOUT is signalled after - * FIFO has been drained, in which case a dummy read of RX FIFO - * is required to clear RX TIMEOUT condition. + * FIFO has been drained or erroneously. + * So apply solution of Errata i2310 as mentioned in + * https://www.ti.com/lit/pdf/sprz536 */ if (priv->habit & UART_RX_TIMEOUT_QUIRK && - (iir & UART_IIR_RX_TIMEOUT) == UART_IIR_RX_TIMEOUT && - serial_port_in(port, UART_OMAP_RX_LVL) == 0) { - serial_port_in(port, UART_RX); + (iir & UART_IIR_RX_TIMEOUT) == UART_IIR_RX_TIMEOUT) { + unsigned char efr2, timeout_h, timeout_l; + + efr2 = serial_in(up, UART_OMAP_EFR2); + timeout_h = serial_in(up, UART_OMAP_TO_H); + timeout_l = serial_in(up, UART_OMAP_TO_L); + serial_out(up, UART_OMAP_TO_H, 0xFF); + serial_out(up, UART_OMAP_TO_L, 0xFF); + serial_out(up, UART_OMAP_EFR2, UART_OMAP_EFR2_TIMEOUT_BEHAVE); + serial_in(up, UART_IIR); + serial_out(up, UART_OMAP_EFR2, efr2); + serial_out(up, UART_OMAP_TO_H, timeout_h); + serial_out(up, UART_OMAP_TO_L, timeout_l); }

/* Stop processing interrupts on input overrun */