From: Marijn Suijten marijn.suijten@somainline.org
[ Upstream commit c05b21ebc5bce3ecc78c2c71afd76d92c790a2ac ]
The strings passed in DT may possibly cause out-of-bounds register accesses and should be validated before use.
Fixes: 775d2ffb4af6 ("backlight: qcom-wled: Restructure the driver for WLED3") Signed-off-by: Marijn Suijten marijn.suijten@somainline.org Reviewed-by: AngeloGioacchino Del Regno angelogioacchino.delregno@somainline.org Reviewed-by: Daniel Thompson daniel.thompson@linaro.org Signed-off-by: Lee Jones lee.jones@linaro.org Link: https://lore.kernel.org/r/20211115203459.1634079-2-marijn.suijten@somainline... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/video/backlight/qcom-wled.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c index cd11c57764381..2c4290f082025 100644 --- a/drivers/video/backlight/qcom-wled.c +++ b/drivers/video/backlight/qcom-wled.c @@ -1528,12 +1528,28 @@ static int wled_configure(struct wled *wled) string_len = of_property_count_elems_of_size(dev->of_node, "qcom,enabled-strings", sizeof(u32)); - if (string_len > 0) + if (string_len > 0) { + if (string_len > wled->max_string_count) { + dev_err(dev, "Cannot have more than %d strings\n", + wled->max_string_count); + return -EINVAL; + } + of_property_read_u32_array(dev->of_node, "qcom,enabled-strings", wled->cfg.enabled_strings, sizeof(u32));
+ for (i = 0; i < string_len; ++i) { + if (wled->cfg.enabled_strings[i] >= wled->max_string_count) { + dev_err(dev, + "qcom,enabled-strings index %d at %d is out of bounds\n", + wled->cfg.enabled_strings[i], i); + return -EINVAL; + } + } + } + return 0; }