dmaengine: bcm-sba-raid: fix device leak on probe

commit 7c3a46ebf15a9796b763a54272407fdbf945bed8 upstream.

Make sure to drop the reference taken when looking up the mailbox device
during probe on probe failures and on driver unbind.

Fixes: 743e1c8 ("dmaengine: Add Broadcom SBA RAID driver")
Cc: stable@vger.kernel.org	# 4.13
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://patch.msgid.link/20251117161258.10679-4-johan@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: jhovold

drivers/dma/bcm-sba-raid.c

@@ -1699,7 +1699,7 @@ static int sba_probe(struct platform_device *pdev)
 	/* Prealloc channel resource */
 	ret = sba_prealloc_channel_resources(sba);
 	if (ret)
-		goto fail_free_mchan;
+		goto fail_put_mbox;
 
 	/* Check availability of debugfs */
 	if (!debugfs_initialized())
@@ -1729,6 +1729,8 @@ static int sba_probe(struct platform_device *pdev)
 fail_free_resources:
 	debugfs_remove_recursive(sba->root);
 	sba_freeup_channel_resources(sba);
+fail_put_mbox:
+	put_device(sba->mbox_dev);
 fail_free_mchan:
 	mbox_free_channel(sba->mchan);
 	return ret;
@@ -1744,6 +1746,8 @@ static void sba_remove(struct platform_device *pdev)
 
 	sba_freeup_channel_resources(sba);
 
+	put_device(sba->mbox_dev);
+
 	mbox_free_channel(sba->mchan);
 }