diff options
| author | Dan Carpenter <error27@gmail.com> | 2026-05-25 10:15:16 +0300 |
|---|---|---|
| committer | Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com> | 2026-05-28 15:23:40 +0200 |
| commit | 8a122b5e72cc0043705f0d524bcd15f0c0b3ec15 (patch) | |
| tree | 648a44d6abc1142c1afdc427b779dd4358a88900 | |
| parent | 9d7697fabbc72428f981c01ddbe0a6be0ce8b6fa (diff) | |
gpio: virtuser: Fix uninitialized data bug in gpio_virtuser_direction_do_write()
If *ppos is non-zero (user-space write split over multiple calls to
write()) then simple_write_to_buffer() won't initialize the start of the
buffer. Really, non-zero values for *ppos aren't going to work at all.
Check for that and return -EINVAL at the start of the function.
Fixes: 91581c4b3f29 ("gpio: virtuser: new virtual testing driver for the GPIO API")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Link: https://patch.msgid.link/ahP3BJWWy-m_qI0X@stanley.mountain
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
| -rw-r--r-- | drivers/gpio/gpio-virtuser.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpio/gpio-virtuser.c b/drivers/gpio/gpio-virtuser.c index 128520d340d4..846f8688fec5 100644 --- a/drivers/gpio/gpio-virtuser.c +++ b/drivers/gpio/gpio-virtuser.c @@ -397,7 +397,7 @@ static ssize_t gpio_virtuser_direction_do_write(struct file *file, char buf[32], *trimmed; int ret, dir, val = 0; - if (count >= sizeof(buf)) + if (*ppos != 0 || count >= sizeof(buf)) return -EINVAL; ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, user_buf, count); @@ -622,7 +622,7 @@ static ssize_t gpio_virtuser_consumer_write(struct file *file, char buf[GPIO_VIRTUSER_NAME_BUF_LEN + 2]; int ret; - if (count >= sizeof(buf)) + if (*ppos != 0 || count >= sizeof(buf)) return -EINVAL; ret = simple_write_to_buffer(buf, GPIO_VIRTUSER_NAME_BUF_LEN, ppos, |