lkml.org 
[lkml]   [2021]   [Oct]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 04/10] backlight: qcom-wled: Validate enabled string indices in DT
    On Mon, Oct 04, 2021 at 09:27:35PM +0200, Marijn Suijten wrote:
    > 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")

    The first half of this patch actually fixes patch 1 from this patch set.
    It would be better to move that code there.


    Daniel.


    > Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
    > Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
    > ---
    > drivers/video/backlight/qcom-wled.c | 14 ++++++++++++++
    > 1 file changed, 14 insertions(+)
    >
    > diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
    > index 29910e603c42..27e8949c7922 100644
    > --- a/drivers/video/backlight/qcom-wled.c
    > +++ b/drivers/video/backlight/qcom-wled.c
    > @@ -1526,6 +1526,12 @@ static int wled_configure(struct wled *wled)
    > "qcom,enabled-strings",
    > sizeof(u32));
    > 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;
    > + }
    > +
    > rc = of_property_read_u32_array(dev->of_node,
    > "qcom,enabled-strings",
    > wled->cfg.enabled_strings,
    > @@ -1537,6 +1543,14 @@ static int wled_configure(struct wled *wled)
    > return -EINVAL;
    > }
    >
    > + 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;
    > + }
    > + }
    > +
    > cfg->num_strings = string_len;
    > }
    >
    > --
    > 2.33.0
    >

    \
     
     \ /
      Last update: 2021-10-05 11:15    [W:4.136 / U:0.644 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site