Re: [PATCH AUTOSEL 5.13 184/189] flow_offload: action should not be NULL when it is referenced

Eric Dumazet
2021-08-06T09:30:13Z

On 7/6/21 1:14 PM, Sasha Levin wrote:
> From: gushengxian <gushengxian@yulong.com>
>
> [ Upstream commit 9ea3e52c5bc8bb4a084938dc1e3160643438927a ]
>
> "action" should not be NULL when it is referenced.
>
> Signed-off-by: gushengxian <13145886936@163.com>
> Signed-off-by: gushengxian <gushengxian@yulong.com>
> Signed-off-by: David S. Miller <davem@davemloft.net>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
> include/net/flow_offload.h | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h
> index dc5c1e69cd9f..69c9eabf8325 100644
> --- a/include/net/flow_offload.h
> +++ b/include/net/flow_offload.h
> @@ -319,12 +319,14 @@ flow_action_mixed_hw_stats_check(const struct flow_action *action,
> if (flow_offload_has_one_action(action))
> return true;
>
> - flow_action_for_each(i, action_entry, action) {
> - if (i && action_entry->hw_stats != last_hw_stats) {
> - NL_SET_ERR_MSG_MOD(extack, "Mixing HW stats types for actions is not supported");
> - return false;
> + if (action) {
> + flow_action_for_each(i, action_entry, action) {
> + if (i && action_entry->hw_stats != last_hw_stats) {
> + NL_SET_ERR_MSG_MOD(extack, "Mixing HW stats types for actions is not supported");
> + return false;
> + }
> + last_hw_stats = action_entry->hw_stats;
> }
> - last_hw_stats = action_entry->hw_stats;
> }
> return true;
> }
>

This patch makes no sense really.

If action is NULL, a crash would happen earlier anyway in

if (flow_offload_has_one_action(action))
return true;

Also, I wonder why it has been backported to stable version,
there was no Fixes: tag in the submission.