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);
> 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
>
>
