Commit 7f9ab862e05c ("leds: spi-byte: Call of_node_put() on error path") was merged in 6.11 and then backported to stable trees through 5.10. It relocates the line that initializes the variable 'child' to a later point in spi_byte_probe().
Versions < 6.9 do not have commit ccc35ff2fd29 ("leds: spi-byte: Use devm_led_classdev_register_ext()"), which removes a line that reads a property from 'child' before its new initialization point. Consequently, spi_byte_probe() reads from an uninitialized device node in stable kernels 6.6-5.10.
Initialize 'child' before it is first accessed.
Fixes: 7f9ab862e05c ("leds: spi-byte: Call of_node_put() on error path") Signed-off-by: Tiffany Yang ynaffit@google.com
---
As an alternative to moving the initialization of 'child' up, Fedor Pchelkin proposed [1] backporting the change that removes the intermediate access.
[1] https://lore.kernel.org/stable/20241029204128.527033-1-pchelkin@ispras.ru/ --- drivers/leds/leds-spi-byte.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/leds/leds-spi-byte.c b/drivers/leds/leds-spi-byte.c index afe9bff7c7c1..4520df1e2341 100644 --- a/drivers/leds/leds-spi-byte.c +++ b/drivers/leds/leds-spi-byte.c @@ -96,6 +96,7 @@ static int spi_byte_probe(struct spi_device *spi) if (!led) return -ENOMEM;
+ child = of_get_next_available_child(dev_of_node(dev), NULL); of_property_read_string(child, "label", &name); strscpy(led->name, name, sizeof(led->name)); led->spi = spi; @@ -106,7 +107,6 @@ static int spi_byte_probe(struct spi_device *spi) led->ldev.max_brightness = led->cdef->max_value - led->cdef->off_value; led->ldev.brightness_set_blocking = spi_byte_brightness_set_blocking;
- child = of_get_next_available_child(dev_of_node(dev), NULL); state = of_get_property(child, "default-state", NULL); if (state) { if (!strcmp(state, "on")) {