2023-05-23 02:20:36

by Azeem Shaikh

Subject: [PATCH] leds: Replace all non-returning strlcpy with strscpy

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <[email protected]>
---
drivers/leds/flash/leds-aat1290.c | 2 +-
drivers/leds/led-class.c | 2 +-
drivers/leds/leds-spi-byte.c | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/leds/flash/leds-aat1290.c b/drivers/leds/flash/leds-aat1290.c
index 589484b22c79..f12ecb2c6580 100644
--- a/drivers/leds/flash/leds-aat1290.c
+++ b/drivers/leds/flash/leds-aat1290.c
@@ -425,7 +425,7 @@ static void aat1290_init_v4l2_flash_config(struct aat1290_led *led,
struct led_classdev *led_cdev = &led->fled_cdev.led_cdev;
struct led_flash_setting *s;

- strlcpy(v4l2_sd_cfg->dev_name, led_cdev->dev->kobj.name,
+ strscpy(v4l2_sd_cfg->dev_name, led_cdev->dev->kobj.name,
sizeof(v4l2_sd_cfg->dev_name));

s = &v4l2_sd_cfg->intensity;
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 9255bc11f99d..6dae56b914fe 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -409,7 +409,7 @@ static int led_classdev_next_name(const char *init_name, char *name,
int ret = 0;
struct device *dev;

- strlcpy(name, init_name, len);
+ strscpy(name, init_name, len);

while ((ret < len) &&
(dev = class_find_device_by_name(leds_class, name))) {
diff --git a/drivers/leds/leds-spi-byte.c b/drivers/leds/leds-spi-byte.c
index 2bc5c99daf51..2c7ffc3c78e6 100644
--- a/drivers/leds/leds-spi-byte.c
+++ b/drivers/leds/leds-spi-byte.c
@@ -98,7 +98,7 @@ static int spi_byte_probe(struct spi_device *spi)
return -ENOMEM;

of_property_read_string(child, "label", &name);
- strlcpy(led->name, name, sizeof(led->name));
+ strscpy(led->name, name, sizeof(led->name));
led->spi = spi;
mutex_init(&led->mutex);
led->cdef = device_get_match_data(dev);

2023-05-23 17:31:59

by Kees Cook

Subject: Re: [PATCH] leds: Replace all non-returning strlcpy with strscpy

On Tue, May 23, 2023 at 02:14:51AM +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
>
> Signed-off-by: Azeem Shaikh <[email protected]>

Reviewed-by: Kees Cook <[email protected]>

--
Kees Cook

2023-05-25 11:35:07

by Lee Jones

Subject: Re: [PATCH] leds: Replace all non-returning strlcpy with strscpy

On Tue, 23 May 2023, Azeem Shaikh wrote:

> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
>
> Signed-off-by: Azeem Shaikh <[email protected]>
> ---
> drivers/leds/flash/leds-aat1290.c | 2 +-
> drivers/leds/led-class.c | 2 +-
> drivers/leds/leds-spi-byte.c | 2 +-
> 3 files changed, 3 insertions(+), 3 deletions(-)

Applied, thanks

--
Lee Jones [李琼斯]