From: Sergey Matsievskiy matsievskiysv@gmail.com

mainline inclusion from mainline-v6.12-rc4 commit 93b8ddc54507a227087c60a0013ed833b6ae7d3c category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IB2YX2 CVE: CVE-2024-50196

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

--------------------------------

The current implementation only calls chained_irq_enter() and chained_irq_exit() if it detects pending interrupts.

``` for (i = 0; i < info->stride; i++) { uregmap_read(info->map, id_reg + 4 * i, &reg); if (!reg) continue;

chained_irq_enter(parent_chip, desc); ```

However, in case of GPIO pin configured in level mode and the parent controller configured in edge mode, GPIO interrupt might be lowered by the hardware. In the result, if the interrupt is short enough, the parent interrupt is still pending while the GPIO interrupt is cleared; chained_irq_enter() never gets called and the system hangs trying to service the parent interrupt.

Moving chained_irq_enter() and chained_irq_exit() outside the for loop ensures that they are called even when GPIO interrupt is lowered by the hardware.

The similar code with chained_irq_enter() / chained_irq_exit() functions wrapping interrupt checking loop may be found in many other drivers: ``` grep -r -A 10 chained_irq_enter drivers/pinctrl ```

Cc: stable@vger.kernel.org Signed-off-by: Sergey Matsievskiy matsievskiysv@gmail.com Reviewed-by: Alexandre Belloni alexandre.belloni@bootlin.com Link: https://lore.kernel.org/20241012105743.12450-2-matsievskiysv@gmail.com Signed-off-by: Linus Walleij linus.walleij@linaro.org Conflicts: drivers/pinctrl/pinctrl-ocelot.c [Fix context conflicts.] Signed-off-by: Zeng Heng zengheng4@huawei.com --- drivers/pinctrl/pinctrl-ocelot.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-ocelot.c b/drivers/pinctrl/pinctrl-ocelot.c index a4a1b00f7f0d..e8ee2ade5293 100644 --- a/drivers/pinctrl/pinctrl-ocelot.c +++ b/drivers/pinctrl/pinctrl-ocelot.c @@ -1097,22 +1097,21 @@ static void ocelot_irq_handler(struct irq_desc *desc) unsigned int reg = 0, irq, i; unsigned long irqs;

+ chained_irq_enter(parent_chip, desc); + for (i = 0; i < info->stride; i++) { regmap_read(info->map, id_reg + 4 * i, &reg); if (!reg) continue;

- chained_irq_enter(parent_chip, desc); - irqs = reg;

for_each_set_bit(irq, &irqs, min(32U, info->desc->npins - 32 * i)) generic_handle_irq(irq_linear_revmap(chip->irq.domain, irq + 32 * i)); - - chained_irq_exit(parent_chip, desc); } + chained_irq_exit(parent_chip, desc); }

static int ocelot_gpiochip_register(struct platform_device *pdev,