Re: [PATCH] clk: imx: Fix an out-of-bounds access in dispmix_csr_clk_dev_data

[Xiaolei Wang <xiaolei.wang@windriver.com>]

On 6/17/25 03:24, Frank Li wrote:
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> On Sat, Jun 14, 2025 at 07:22:55PM +0800, Xiaolei Wang wrote:
>> When num_parents is 4, __clk_register() occurs an out-of-bounds
>> when accessing parent_names member.
>>
>>   BUG: KASAN: global-out-of-bounds in __clk_register+0x1844/0x20d8
>>   Read of size 8 at addr ffff800086988e78 by task kworker/u24:3/59
>>    Hardware name: NXP i.MX95 19X19 board (DT)
>>    Workqueue: events_unbound deferred_probe_work_func
>>    Call trace:
>>      dump_backtrace+0x94/0xec
>>      show_stack+0x18/0x24
>>      dump_stack_lvl+0x8c/0xcc
>>      print_report+0x398/0x5fc
>>      kasan_report+0xd4/0x114
>>      __asan_report_load8_noabort+0x20/0x2c
>>      __clk_register+0x1844/0x20d8
>>      clk_hw_register+0x44/0x110
>>      __clk_hw_register_mux+0x284/0x3a8
>>      imx95_bc_probe+0x4f4/0xa70
>>
>> Fixes: 5224b189462f ("clk: imx: add i.MX95 BLK CTL clk driver")
>> Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
>> ---
>>   drivers/clk/imx/clk-imx95-blk-ctl.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/clk/imx/clk-imx95-blk-ctl.c b/drivers/clk/imx/clk-imx95-blk-ctl.c
>> index 25974947ad0c..fd11932b12b3 100644
>> --- a/drivers/clk/imx/clk-imx95-blk-ctl.c
>> +++ b/drivers/clk/imx/clk-imx95-blk-ctl.c
>> @@ -223,7 +223,7 @@ static const struct imx95_blk_ctl_clk_dev_data dispmix_csr_clk_dev_data[] = {
>>        [IMX95_CLK_DISPMIX_ENG0_SEL] = {
>>                .name = "disp_engine0_sel",
>>                .parent_names = (const char *[]){"videopll1", "dsi_pll", "ldb_pll_div7", },
>> -             .num_parents = 4,
>> +             .num_parents = 3,
> Although this is simple fix, is it possible to change to
>
> const char *parent[] = {"videopll1", "dsi_pll", "ldb_pll_div7"}
> num_parents = ARRAY_SIZE(parent);
>
> to avoid hardcode number here.

Thanks for the suggestion frank, I will send a v2 version

thanks

xiaolei

>
> Frank
>
>>                .reg = 0,
>>                .bit_idx = 0,
>>                .bit_width = 2,
>> @@ -233,7 +233,7 @@ static const struct imx95_blk_ctl_clk_dev_data dispmix_csr_clk_dev_data[] = {
>>        [IMX95_CLK_DISPMIX_ENG1_SEL] = {
>>                .name = "disp_engine1_sel",
>>                .parent_names = (const char *[]){"videopll1", "dsi_pll", "ldb_pll_div7", },
>> -             .num_parents = 4,
>> +             .num_parents = 3,
>>                .reg = 0,
>>                .bit_idx = 2,
>>                .bit_width = 2,
>> --
>> 2.43.0
>>