On 2022/12/10 4:59, Rob Herring wrote:
> On Tue, Dec 06, 2022 at 04:36:57PM +0800, ruanjinjie wrote:
>> when kmalloc() fail to allocate memory in kasprintf(), fn_1 or fn_2 will
>> be NULL, strcmp() will cause null pointer dereference.
>>
>> Fixes: 2fe0e8769df9 ("of: overlay: check prevents multiple fragments touching same property")
>> Signed-off-by: ruanjinjie <ruanjinjie@xxxxxxxxxx>
>> ---
>> drivers/of/overlay.c | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
>> index bd8ff4df723d..49c066b51148 100644
>> --- a/drivers/of/overlay.c
>> +++ b/drivers/of/overlay.c
>> @@ -545,6 +545,11 @@ static int find_dup_cset_node_entry(struct overlay_changeset *ovcs,
>>
>> fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
>> fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
>> + if (!fn_1 || !fn_2) {
>> + kfree(fn_1);
>> + kfree(fn_2);
>> + return -ENOMEM;
>> + }
>> node_path_match = !strcmp(fn_1, fn_2);
>
> We don't actually care what the return code is, so just change this to:
>
> node_path_match = !fn_1 || !fn_2 || !strcmp(fn_1, fn_2);
Thank you very much!I'll give the v2 patch soon.
>
>> kfree(fn_1);
>> kfree(fn_2);
>> @@ -580,6 +585,11 @@ static int find_dup_cset_prop(struct overlay_changeset *ovcs,
>>
>> fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
>> fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
>> + if (!fn_1 || !fn_2) {
>> + kfree(fn_1);
>> + kfree(fn_2);
>> + return -ENOMEM;
>> + }
>> node_path_match = !strcmp(fn_1, fn_2);
>> kfree(fn_1);
>> kfree(fn_2);
>> --
>> 2.25.1
>>
>>
>
