[PATCH net] dm9000: free the wake IRQ before releasing board resources

[PATCH net] dm9000: free the wake IRQ before releasing board resources

[Myeonghun Pak]

dm9000_probe() requests an optional wake IRQ with the net_device as its
cookie, but neither probe unwind nor removal frees it. The handler accesses
the private board data and its MMIO mappings, which are released by
dm9000_release_board() and free_netdev().

Track successful IRQ registration separately from wake_supported: the wake
capability test can fail after request_irq() succeeds. Free the registered
IRQ in the common board cleanup before unmapping registers, waiting for any
running handler before releasing its resources. This covers both later
probe failures and removal without freeing an IRQ whose request failed.

This issue was identified during our ongoing static-analysis research while
reviewing kernel code.

Fixes: c029f4440fd3 ("DM9000: Wake on LAN support")
Cc: stable@vger.kernel.org
Assisted-by: OpenAI:GPT-5.6
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
---
 drivers/net/ethernet/davicom/dm9000.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/davicom/dm9000.c b/drivers/net/ethernet/davicom/dm9000.c
index b87eaf0c2..c8ff07fe3 100644
--- a/drivers/net/ethernet/davicom/dm9000.c
+++ b/drivers/net/ethernet/davicom/dm9000.c
@@ -104,6 +104,7 @@ struct board_info {
 	unsigned int	in_timeout:1;
 	unsigned int	in_suspend:1;
 	unsigned int	wake_supported:1;
+	unsigned int	wake_irq_requested:1;
 
 	enum dm9000_type type;
 
@@ -802,6 +803,9 @@ dm9000_poll_work(struct work_struct *w)
 static void
 dm9000_release_board(struct platform_device *pdev, struct board_info *db)
 {
+	if (db->wake_irq_requested)
+		free_irq(db->irq_wake, db->ndev);
+
 	/* unmap our resources */
 
 	iounmap(db->io_addr);
@@ -1519,6 +1523,7 @@ dm9000_probe(struct platform_device *pdev)
 		if (ret) {
 			dev_err(db->dev, "cannot get wakeup irq (%d)\n", ret);
 		} else {
+			db->wake_irq_requested = 1;
 
 			/* test to see if irq is really wakeup capable */
 			ret = irq_set_irq_wake(db->irq_wake, 1);