From: Geert Uytterhoeven geert+renesas@glider.be
[ Upstream commit 357798909164bf423eac6a78ff7da7e98d2d7f7f ]
The err_remove_chip block is too coarse, and may perform cleanup that must not be done. E.g. if of_gpiochip_add() fails, of_gpiochip_remove() is still called, causing:
OF: ERROR: Bad of_node_put() on /soc/gpio@e6050000 CPU: 1 PID: 20 Comm: kworker/1:1 Not tainted 5.1.0-rc2-koelsch+ #407 Hardware name: Generic R-Car Gen2 (Flattened Device Tree) Workqueue: events deferred_probe_work_func [<c020ec74>] (unwind_backtrace) from [<c020ae58>] (show_stack+0x10/0x14) [<c020ae58>] (show_stack) from [<c07c1224>] (dump_stack+0x7c/0x9c) [<c07c1224>] (dump_stack) from [<c07c5a80>] (kobject_put+0x94/0xbc) [<c07c5a80>] (kobject_put) from [<c0470420>] (gpiochip_add_data_with_key+0x8d8/0xa3c) [<c0470420>] (gpiochip_add_data_with_key) from [<c0473738>] (gpio_rcar_probe+0x1d4/0x314) [<c0473738>] (gpio_rcar_probe) from [<c052fca8>] (platform_drv_probe+0x48/0x94)
and later, if a GPIO consumer tries to use a GPIO from a failed controller:
WARNING: CPU: 0 PID: 1 at lib/refcount.c:156 kobject_get+0x38/0x4c refcount_t: increment on 0; use-after-free. Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.1.0-rc2-koelsch+ #407 Hardware name: Generic R-Car Gen2 (Flattened Device Tree) [<c020ec74>] (unwind_backtrace) from [<c020ae58>] (show_stack+0x10/0x14) [<c020ae58>] (show_stack) from [<c07c1224>] (dump_stack+0x7c/0x9c) [<c07c1224>] (dump_stack) from [<c0221580>] (__warn+0xd0/0xec) [<c0221580>] (__warn) from [<c02215e0>] (warn_slowpath_fmt+0x44/0x6c) [<c02215e0>] (warn_slowpath_fmt) from [<c07c58fc>] (kobject_get+0x38/0x4c) [<c07c58fc>] (kobject_get) from [<c068b3ec>] (of_node_get+0x14/0x1c) [<c068b3ec>] (of_node_get) from [<c0686f24>] (of_find_node_by_phandle+0xc0/0xf0) [<c0686f24>] (of_find_node_by_phandle) from [<c0686fbc>] (of_phandle_iterator_next+0x68/0x154) [<c0686fbc>] (of_phandle_iterator_next) from [<c0687fe4>] (__of_parse_phandle_with_args+0x40/0xd0) [<c0687fe4>] (__of_parse_phandle_with_args) from [<c0688204>] (of_parse_phandle_with_args_map+0x100/0x3ac) [<c0688204>] (of_parse_phandle_with_args_map) from [<c0471240>] (of_get_named_gpiod_flags+0x38/0x380) [<c0471240>] (of_get_named_gpiod_flags) from [<c046f864>] (gpiod_get_from_of_node+0x24/0xd8) [<c046f864>] (gpiod_get_from_of_node) from [<c0470aa4>] (devm_fwnode_get_index_gpiod_from_child+0xa0/0x144) [<c0470aa4>] (devm_fwnode_get_index_gpiod_from_child) from [<c05f425c>] (gpio_keys_probe+0x418/0x7bc) [<c05f425c>] (gpio_keys_probe) from [<c052fca8>] (platform_drv_probe+0x48/0x94)
Fix this by splitting the cleanup block, and adding a missing call to gpiochip_irqchip_remove().
Fixes: 28355f81969962cf ("gpio: defer probe if pinctrl cannot be found") Signed-off-by: Geert Uytterhoeven geert+renesas@glider.be Reviewed-by: Mukesh Ojha mojha@codeaurora.org Signed-off-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpio/gpiolib.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index d1adfdf50fb3..34fbf879411f 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1379,7 +1379,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
status = gpiochip_add_irqchip(chip, lock_key, request_key); if (status) - goto err_remove_chip; + goto err_free_gpiochip_mask;
status = of_gpiochip_add(chip); if (status) @@ -1387,7 +1387,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
status = gpiochip_init_valid_mask(chip); if (status) - goto err_remove_chip; + goto err_remove_of_chip;
for (i = 0; i < chip->ngpio; i++) { struct gpio_desc *desc = &gdev->descs[i]; @@ -1415,14 +1415,18 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, if (gpiolib_initialized) { status = gpiochip_setup_dev(gdev); if (status) - goto err_remove_chip; + goto err_remove_acpi_chip; } return 0;
-err_remove_chip: +err_remove_acpi_chip: acpi_gpiochip_remove(chip); +err_remove_of_chip: gpiochip_free_hogs(chip); of_gpiochip_remove(chip); +err_remove_chip: + gpiochip_irqchip_remove(chip); +err_free_gpiochip_mask: gpiochip_free_valid_mask(chip); err_remove_irqchip_mask: gpiochip_irqchip_free_valid_mask(chip);