2020-04-29 14:00:10

by Takashi Iwai

Subject: [PATCH] gpio: exar: Fix bad handling for ida_simple_get error path

The commit 7ecced0934e5 ("gpio: exar: add a check for the return value
of ida_simple_get fails") added a goto jump to the common error
handler for ida_simple_get() error, but this is wrong in two ways:
it doesn't set the proper return code and, more badly, it invokes
ida_simple_remove() with a negative index that shall lead to a kernel
panic via BUG_ON().

This patch addresses those two issues.

Fixes: 7ecced0934e5 ("gpio: exar: add a check for the return value of ida_simple_get fails")
Cc: <[email protected]>
Signed-off-by: Takashi Iwai <[email protected]>
---
drivers/gpio/gpio-exar.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c
index da1ef0b1c291..b1accfba017d 100644
--- a/drivers/gpio/gpio-exar.c
+++ b/drivers/gpio/gpio-exar.c
@@ -148,8 +148,10 @@ static int gpio_exar_probe(struct platform_device *pdev)
mutex_init(&exar_gpio->lock);

index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL);
- if (index < 0)
- goto err_destroy;
+ if (index < 0) {
+ ret = index;
+ goto err_mutex_destroy;
+ }

sprintf(exar_gpio->name, "exar_gpio%d", index);
exar_gpio->gpio_chip.label = exar_gpio->name;
@@ -176,6 +178,7 @@ static int gpio_exar_probe(struct platform_device *pdev)

err_destroy:
ida_simple_remove(&ida_index, index);
+err_mutex_destroy:
mutex_destroy(&exar_gpio->lock);
return ret;
}
--
2.16.4

2020-05-05 16:29:44

by Bartosz Golaszewski

Subject: Re: [PATCH] gpio: exar: Fix bad handling for ida_simple_get error path

śr., 29 kwi 2020 o 15:56 Takashi Iwai <[email protected]> napisał(a):
>
> The commit 7ecced0934e5 ("gpio: exar: add a check for the return value
> of ida_simple_get fails") added a goto jump to the common error
> handler for ida_simple_get() error, but this is wrong in two ways:
> it doesn't set the proper return code and, more badly, it invokes
> ida_simple_remove() with a negative index that shall lead to a kernel
> panic via BUG_ON().
>
> This patch addresses those two issues.
>
> Fixes: 7ecced0934e5 ("gpio: exar: add a check for the return value of ida_simple_get fails")
> Cc: <[email protected]>
> Signed-off-by: Takashi Iwai <[email protected]>

Patch applied for fixes, thanks!

Bart