[PATCH v2] wifi: ath11k: fix resource leak on error in ext IRQ setup

[ZhaoJinming]

In ath11k_ahb_config_irq(), when a CE request_irq() fails, the function
returns the error immediately without freeing the CE IRQs that were
successfully registered in previous loop iterations. The probe error
path does not call ath11k_ahb_free_irq() either, so the previously
registered CE IRQ handlers remain attached to the interrupt lines and
are never released.

In ath11k_ahb_config_ext_irq(), when an external request_irq() fails,
the error is only logged and the loop continues. The function then
returns 0 indicating success, leaving the device in a partially
configured state where some external IRQs are not registered. This
causes enable_irq()/disable_irq()/free_irq() to be called on
unregistered IRQs during runtime and remove/shutdown, triggering
WARN_ON(!desc->action), and missing interrupt handlers lead to data
loss.

Additionally, if alloc_netdev_dummy() fails for a later IRQ group, the
function returns -ENOMEM without freeing the ext IRQs and napi_ndev
that were successfully set up for earlier groups.

Fix all three issues: propagate the error up to the caller and unwind
all successfully registered IRQs and allocated resources on failure.

Signed-off-by: ZhaoJinming <zhaojinming at uniontech.com>
---

Changes in v2:
- Move `irq_grp` declaration from for-loop body to function scope to fix
  compile error in err_request_irq error path.
- Set ret = -ENOMEM before goto err_request_irq on alloc_netdev_dummy()
  failure to avoid returning uninitialized value.
- When ath11k_ahb_config_ext_irq() fails, unwind the already-registered
  CE IRQs via a shared err_ce_irq cleanup path to avoid leaking them.

 drivers/net/wireless/ath/ath11k/ahb.c | 48 ++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/ahb.c b/drivers/net/wireless/ath/ath11k/ahb.c
index f566d699d074..11bafbd94aff 100644
--- a/drivers/net/wireless/ath/ath11k/ahb.c
+++ b/drivers/net/wireless/ath/ath11k/ahb.c
@@ -524,20 +524,24 @@ static irqreturn_t ath11k_ahb_ext_interrupt_handler(int irq, void *arg)
 static int ath11k_ahb_config_ext_irq(struct ath11k_base *ab)
 {
 	struct ath11k_hw_params *hw = &ab->hw_params;
+	struct ath11k_ext_irq_grp *irq_grp;
 	int i, j;
 	int irq;
 	int ret;
 
 	for (i = 0; i < ATH11K_EXT_IRQ_GRP_NUM_MAX; i++) {
-		struct ath11k_ext_irq_grp *irq_grp = &ab->ext_irq_grp[i];
+		irq_grp = &ab->ext_irq_grp[i];
 		u32 num_irq = 0;
 
 		irq_grp->ab = ab;
 		irq_grp->grp_id = i;
 
 		irq_grp->napi_ndev = alloc_netdev_dummy(0);
-		if (!irq_grp->napi_ndev)
-			return -ENOMEM;
+		if (!irq_grp->napi_ndev) {
+			ret = -ENOMEM;
+			irq_grp->num_irq = 0;
+			goto err_request_irq;
+		}
 
 		netif_napi_add(irq_grp->napi_ndev, &irq_grp->napi,
 			       ath11k_ahb_ext_grp_napi_poll);
@@ -600,11 +604,25 @@ static int ath11k_ahb_config_ext_irq(struct ath11k_base *ab)
 			if (ret) {
 				ath11k_err(ab, "failed request_irq for %d\n",
 					   irq);
+				irq_grp->num_irq = j;
+				goto err_request_irq;
 			}
 		}
 	}
 
 	return 0;
+
+err_request_irq:
+	for ( ; i >= 0; i--) {
+		irq_grp = &ab->ext_irq_grp[i];
+		for (j = irq_grp->num_irq - 1; j >= 0; j--)
+			free_irq(ab->irq_num[irq_grp->irqs[j]], irq_grp);
+		if (irq_grp->napi_ndev) {
+			netif_napi_del(&irq_grp->napi);
+			free_netdev(irq_grp->napi_ndev);
+		}
+	}
+	return ret;
 }
 
 static int ath11k_ahb_config_irq(struct ath11k_base *ab)
@@ -629,15 +647,30 @@ static int ath11k_ahb_config_irq(struct ath11k_base *ab)
 		ret = request_irq(irq, ath11k_ahb_ce_interrupt_handler,
 				  IRQF_TRIGGER_RISING, irq_name[irq_idx],
 				  ce_pipe);
-		if (ret)
-			return ret;
+		if (ret) {
+			ath11k_err(ab, "failed request_irq for %d\n", irq);
+			goto err_ce_irq;
+		}
 
 		ab->irq_num[irq_idx] = irq;
 	}
 
 	/* Configure external interrupts */
 	ret = ath11k_ahb_config_ext_irq(ab);
+	if (ret) {
+		ath11k_err(ab, "failed to configure ext irq: %d\n", ret);
+		goto err_ce_irq;
+	}
+
+	return 0;
 
+err_ce_irq:
+	for (i--; i >= 0; i--) {
+		if (ath11k_ce_get_attr_flags(ab, i) & CE_ATTR_DIS_INTR)
+			continue;
+		free_irq(ab->irq_num[ATH11K_IRQ_CE0_OFFSET + i],
+			 &ab->ce.ce_pipe[i]);
+	}
 	return ret;
 }
 
-- 
2.20.1