On Tue, May 17, 2022 at 05:57:23PM +0800, Yuanjun Gong wrote:
> From: Gong Yuanjun <ruc_gongyuanjun@xxxxxxx>
>
> In hist_trigger_elt_data_alloc(), elt_data is freed by
> hist_elt_data_free() if kcalloc fails.
>
> static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt)
> {
> ...
> elt_data->field_var_str = kcalloc(n_str, sizeof(char *), GFP_KERNEL);
> if (!elt_data->field_var_str) {
> hist_elt_data_free(elt_data);
> return -EINVAL;
> }
> ...}
>
> In hist_elt_data_free() the elt_data->field_var_str field should be
> checked before dereference.
>
> Signed-off-by: Gong Yuanjun <ruc_gongyuanjun@xxxxxxx>
> ---
> kernel/trace/trace_events_hist.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> index 44db5ba9cabb..73177c9f94b2 100644
> --- a/kernel/trace/trace_events_hist.c
> +++ b/kernel/trace/trace_events_hist.c
> @@ -1576,11 +1576,11 @@ static void hist_elt_data_free(struct hist_elt_data *elt_data)
> {
> unsigned int i;
>
> - for (i = 0; i < elt_data->n_field_var_str; i++)
> - kfree(elt_data->field_var_str[i]);
> -
> - kfree(elt_data->field_var_str);
> -
> + if (elt_data->field_var_str) {
> + for (i = 0; i < elt_data->n_field_var_str; i++)
> + kfree(elt_data->field_var_str[i]);
> + kfree(elt_data->field_var_str);
> + }
> kfree(elt_data->comm);
> kfree(elt_data);
> }
> --
> 2.17.1
>
<formletter>
This is not the correct way to submit patches for inclusion in the
stable kernel tree. Please read:
https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.
</formletter>
