| Message ID | 20180723165330.25213-1-vasilyev@ispras.ru |
|---|---|
| State | New |
| Headers | show |
| Series | gpio: ml-ioh: Fix buffer underwrite on probe error path | expand |
On Mon, Jul 23, 2018 at 6:54 PM Anton Vasilyev <vasilyev@ispras.ru> wrote: > If ioh_gpio_probe() fails on devm_irq_alloc_descs() then chip may point > to any element of chip_save array, so reverse iteration from pointer chip > may become chip_save[-1] and gpiochip_remove() will operate with wrong > memory. > > The patch fix the error path of ioh_gpio_probe() to correctly bypass > chip_save array. > > Found by Linux Driver Verification project (linuxtesting.org). > > Signed-off-by: Anton Vasilyev <vasilyev@ispras.ru> Patch applied, nice work! Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/gpio/gpio-ml-ioh.c b/drivers/gpio/gpio-ml-ioh.c index b23d9a36be1f..51c7d1b84c2e 100644 --- a/drivers/gpio/gpio-ml-ioh.c +++ b/drivers/gpio/gpio-ml-ioh.c @@ -496,9 +496,10 @@ static int ioh_gpio_probe(struct pci_dev *pdev, return 0; err_gpiochip_add: + chip = chip_save; while (--i >= 0) { - chip--; gpiochip_remove(&chip->gpio); + chip++; } kfree(chip_save);
If ioh_gpio_probe() fails on devm_irq_alloc_descs() then chip may point to any element of chip_save array, so reverse iteration from pointer chip may become chip_save[-1] and gpiochip_remove() will operate with wrong memory. The patch fix the error path of ioh_gpio_probe() to correctly bypass chip_save array. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Anton Vasilyev <vasilyev@ispras.ru> --- drivers/gpio/gpio-ml-ioh.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)