[PATCH] net: ethernet: fix uninitialized pointers with free attr

[Ally Heev]

Uninitialized pointers with `__free` attribute can cause undefined
behaviour as the memory assigned(randomly) to the pointer is freed
automatically when the pointer goes out of scope

net/ethernet doesn't have any bugs related to this as of now,
but it is better to initialize and assign pointers with `__free` attr
in one statement to ensure proper scope-based cleanup

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Closes: https://lore.kernel.org/all/aPiG_F5EBQUjZqsl@stanley.mountain/
Signed-off-by: Ally Heev <allyheev@xxxxxxxxx>
---
 drivers/net/ethernet/intel/ice/ice_flow.c       | 5 +++--
 drivers/net/ethernet/intel/idpf/idpf_virtchnl.c | 5 +++--
 drivers/net/ethernet/microsoft/mana/gdma_main.c | 2 +-
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_flow.c b/drivers/net/ethernet/intel/ice/ice_flow.c
index 6d5c939dc8a515c252cd2b77d155b69fa264ee92..3590dacf3ee57879b3809d715e40bb290e40c4aa 100644
--- a/drivers/net/ethernet/intel/ice/ice_flow.c
+++ b/drivers/net/ethernet/intel/ice/ice_flow.c
@@ -1573,12 +1573,13 @@ ice_flow_set_parser_prof(struct ice_hw *hw, u16 dest_vsi, u16 fdir_vsi,
 			 struct ice_parser_profile *prof, enum ice_block blk)
 {
 	u64 id = find_first_bit(prof->ptypes, ICE_FLOW_PTYPE_MAX);
-	struct ice_flow_prof_params *params __free(kfree);
 	u8 fv_words = hw->blk[blk].es.fvw;
 	int status;
 	int i, idx;
 
-	params = kzalloc(sizeof(*params), GFP_KERNEL);
+	struct ice_flow_prof_params *params __free(kfree) =
+		kzalloc(sizeof(*params), GFP_KERNEL);
+
 	if (!params)
 		return -ENOMEM;
 
diff --git a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
index cbb5fa30f5a0ec778c1ee30470da3ca21cc1af24..368138715cd55cd1dadc686931cdda51c7a5130d 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
@@ -1012,7 +1012,6 @@ static int idpf_send_get_caps_msg(struct idpf_adapter *adapter)
  */
 static int idpf_send_get_lan_memory_regions(struct idpf_adapter *adapter)
 {
-	struct virtchnl2_get_lan_memory_regions *rcvd_regions __free(kfree);
 	struct idpf_vc_xn_params xn_params = {
 		.vc_op = VIRTCHNL2_OP_GET_LAN_MEMORY_REGIONS,
 		.recv_buf.iov_len = IDPF_CTLQ_MAX_BUF_LEN,
@@ -1023,7 +1022,9 @@ static int idpf_send_get_lan_memory_regions(struct idpf_adapter *adapter)
 	ssize_t reply_sz;
 	int err = 0;
 
-	rcvd_regions = kzalloc(IDPF_CTLQ_MAX_BUF_LEN, GFP_KERNEL);
+	struct virtchnl2_get_lan_memory_regions *rcvd_regions __free(kfree) =
+		kzalloc(IDPF_CTLQ_MAX_BUF_LEN, GFP_KERNEL);
+
 	if (!rcvd_regions)
 		return -ENOMEM;
 
diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c
index 43f034e180c41a595ff570b886569685a56f9fee..8dcba7ee36130d94ba3436c99a5cd5f792a2962e 100644
--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -1505,7 +1505,7 @@ static int irq_setup(unsigned int *irqs, unsigned int len, int node,
 		     bool skip_first_cpu)
 {
 	const struct cpumask *next, *prev = cpu_none_mask;
-	cpumask_var_t cpus __free(free_cpumask_var);
+	cpumask_var_t cpus __free(free_cpumask_var) = NULL;
 	int cpu, weight;
 
 	if (!alloc_cpumask_var(&cpus, GFP_KERNEL))

---
base-commit: c9cfc122f03711a5124b4aafab3211cf4d35a2ac
change-id: 20251105-aheev-uninitialized-free-attr-net-ethernet-7d106e4ab3f7

Best regards,
-- 
Ally Heev <allyheev@xxxxxxxxx>