RE: [Intel-wired-lan] [PATCH net] ice: Fix use-after-scope in ice_sched_add_nodes_to_layer()

[Kwapulinski, Piotr]

>-----Original Message-----
>From: Intel-wired-lan <intel-wired-lan-bounces@xxxxxxxxxx> On Behalf Of NeKon69
>Sent: Saturday, June 13, 2026 12:15 PM
>To: Nguyen, Anthony L <anthony.l.nguyen@xxxxxxxxx>; Kitszel, Przemyslaw <przemyslaw.kitszel@xxxxxxxxx>
>Cc: andrew+netdev@xxxxxxx; davem@xxxxxxxxxxxxx; edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx; pabeni@xxxxxxxxxx; victor.raj@xxxxxxxxx; intel-wired-lan@xxxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; NeKon69 <nobodqwe@xxxxxxxxx>
>Subject: [Intel-wired-lan] [PATCH net] ice: Fix use-after-scope in ice_sched_add_nodes_to_layer()
>
>Commit 7fb09a737536 ("ice: Modify recursive way of adding nodes") changed ice_sched_add_nodes_to_layer() from recursive control flow to an iterative loop.
>
>Inside the loop, first_teid_ptr may be set to the address of a block-local variable:
>
>	u32 temp;
>	...
>	if (num_added)
>		first_teid_ptr = &temp;
>
>On the next loop iteration, first_teid_ptr may be passed to ice_sched_add_nodes_to_hw_layer(), after temp from the previous iteration has gone out of scope.
>
>Move temp outside the loop so the pointer remains valid for the lifetime of ice_sched_add_nodes_to_layer().
>
>This was found by Clang with LifetimeSafety enabled while testing C language support on a Linux allmodconfig build.
>
>Fixes: 7fb09a737536 ("ice: Modify recursive way of adding nodes")
>Link: https://github.com/llvm/llvm-project/pull/203270
>Signed-off-by: NeKon69 <nobodqwe@xxxxxxxxx>
>---
> drivers/net/ethernet/intel/ice/ice_sched.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/drivers/net/ethernet/intel/ice/ice_sched.c b/drivers/net/ethernet/intel/ice/ice_sched.c
>index fff0c1afdb41..089ad3967be5 100644
>--- a/drivers/net/ethernet/intel/ice/ice_sched.c
>+++ b/drivers/net/ethernet/intel/ice/ice_sched.c
>@@ -1074,11 +1074,11 @@ ice_sched_add_nodes_to_layer(struct ice_port_info *pi,
> 	u32 *first_teid_ptr = first_node_teid;
> 	u16 new_num_nodes = num_nodes;
> 	int status = 0;
>+	u32 temp;
> 
> 	*num_nodes_added = 0;
> 	while (*num_nodes_added < num_nodes) {
> 		u16 max_child_nodes, num_added = 0;
>-		u32 temp;
> 
> 		status = ice_sched_add_nodes_to_hw_layer(pi, tc_node, parent,
> 							 layer,	new_num_nodes,
>--
>2.54.0
>

Reviewed-by: Piotr Kwapulinski <piotr.kwapulinski@xxxxxxxxx>