[PATCH v2] net: ethernet: fix uninitialized pointers with free attr

[PATCH v2] 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@linaro.org>
Closes: https://lore.kernel.org/all/aPiG_F5EBQUjZqsl@stanley.mountain/
Signed-off-by: Ally Heev <allyheev@gmail.com>
---
Changes in v2:
- fixed non pointer initialization to NULL
- NOTE: drop v1
- Link to v1: https://lore.kernel.org/r/20251105-aheev-uninitialized-free-attr-net-ethernet-v1-1-f6ea84bbd750@gmail.com
---
 drivers/net/ethernet/intel/ice/ice_flow.c       | 5 +++--
 drivers/net/ethernet/intel/idpf/idpf_virtchnl.c | 5 +++--
 2 files changed, 6 insertions(+), 4 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;
 

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

Best regards,
-- 
Ally Heev <allyheev@gmail.com>

RE: [Intel-wired-lan] [PATCH v2] net: ethernet: fix uninitialized pointers with free attr

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> Of Ally Heev
> Sent: Thursday, November 6, 2025 11:09 AM
> To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
> Przemyslaw <przemyslaw.kitszel@intel.com>; Andrew Lunn
> <andrew+netdev@lunn.ch>; David S. Miller <davem@davemloft.net>; Eric
> Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo
> Abeni <pabeni@redhat.com>; K. Y. Srinivasan <kys@microsoft.com>;
> Haiyang Zhang <haiyangz@microsoft.com>; Wei Liu <wei.liu@kernel.org>;
> Cui, Dexuan <decui@microsoft.com>
> Cc: intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org; linux-hyperv@vger.kernel.org; Dan Carpenter
> <dan.carpenter@linaro.org>; Ally Heev <allyheev@gmail.com>
> Subject: [Intel-wired-lan] [PATCH v2] net: ethernet: fix uninitialized
> pointers with free attr
> 
> 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@linaro.org>
> Closes: https://lore.kernel.org/all/aPiG_F5EBQUjZqsl@stanley.mountain/
> Signed-off-by: Ally Heev <allyheev@gmail.com>
> ---
> Changes in v2:
> - fixed non pointer initialization to NULL
> - NOTE: drop v1
> - Link to v1: https://lore.kernel.org/r/20251105-aheev-uninitialized-
> free-attr-net-ethernet-v1-1-f6ea84bbd750@gmail.com
> ---
...

> Best regards,
> --
> Ally Heev <allyheev@gmail.com>

Good day, Ally

Thanks for addressing the cleanup attribute initialization.
A few upstream‑style nits before this can go in:

Commit message:
  Use US spelling: behavior instead of behaviour.
  Expand abbreviations: replace attr with attribute.
  Drop speculative sentence: “net/ethernet doesn't have any bugs …” – not needed for a fix commit.
  Minor grammar: add a period before “net/ethernet”; remove parentheses in assigned(randomly).

Changelog:
  Hyphenate “non‑pointer” in “fixed non pointer initialization to NULL”.

Subject line:
net: ethernet: fix uninitialized pointers with __free attribute (spell out “attribute”).


Code style:
The new declaration + initializer is good, but please ensure both hunks stay within ~80 columns in drivers/net/*.
Wrapping like this is fine:

struct ice_flow_prof_params *params __free(kfree) =
        kzalloc(sizeof(*params), GFP_KERNEL);

No functional issues found; just these style and commit message cleanups.

Thanks,
Alex

Re: [Intel-wired-lan] [PATCH v2] net: ethernet: fix uninitialized pointers with free attr

[ally heev]

On Thu, 2025-11-06 at 10:18 +0000, Loktionov, Aleksandr wrote:
[..]
> Code style:
> The new declaration + initializer is good, but please ensure both hunks stay within ~80 columns in drivers/net/*.
> Wrapping like this is fine:
> 
> struct ice_flow_prof_params *params __free(kfree) =
>         kzalloc(sizeof(*params), GFP_KERNEL);

I ran checkpatch with `$max_line_length` set to 80. It didn't throw any errors/warnings

Regards,
Ally