[PATCH v3 net] net: microchip: vcap api: Fix possible memory leak in vcap_decode_rule()

The memory allocated for struct vcap_rule_internal, keyfields and
actionfields inside vcap_dup_rule() are not freed in some of the error
paths in vcap_decode_rule(). Fix that by calling vcap_free_rule().

Compile tested only. Issue found using a prototype static analysis tool
built on top of the LLVM compiler infrastructure.

Fixes: 610c32b2ce66 ("net: microchip: vcap: Add vcap_get_rule")
Cc: [email protected]
Reviewed-by: Joe Damato <[email protected]>
Signed-off-by: Abdun Nihaal <[email protected]>
---

v2->v3:
- Rename the error label to "err_free_rule" to denote the first action
  being undone, as suggested by Jakub Kicinski
- Move the information about compile tested only, and how the issue was
  found to the commit message, as suggested by Jakub Kicinski.

v1->v2:
- Convert the error labels from "err" to "out_err" to avoid confusion
  with the err variable, as suggested by Joe Damato.

Link to v1: https://patchwork.kernel.org/project/netdevbpf/patch/[email protected]/
Link to v2: https://patchwork.kernel.org/project/netdevbpf/patch/[email protected]/

 drivers/net/ethernet/microchip/vcap/vcap_api.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/microchip/vcap/vcap_api.c b/drivers/net/ethernet/microchip/vcap/vcap_api.c
index ff86cde11a32..788c0728d763 100644
--- a/drivers/net/ethernet/microchip/vcap/vcap_api.c
+++ b/drivers/net/ethernet/microchip/vcap/vcap_api.c
@@ -2427,18 +2427,21 @@ struct vcap_rule *vcap_decode_rule(struct vcap_rule_internal *elem)
 
 	err = vcap_read_rule(ri);
 	if (err)
-		return ERR_PTR(err);
+		goto err_free_rule;
 
 	err = vcap_decode_keyset(ri);
 	if (err)
-		return ERR_PTR(err);
+		goto err_free_rule;
 
 	err = vcap_decode_actionset(ri);
 	if (err)
-		return ERR_PTR(err);
+		goto err_free_rule;
 
 out:
 	return &ri->data;
+err_free_rule:
+	vcap_free_rule(&ri->data);
+	return ERR_PTR(err);
 }
 
 struct vcap_rule *vcap_get_rule(struct vcap_control *vctrl, u32 id)
-- 
2.43.0