[PATCH wireless] wifi: libertas: fix memory leak in helper_firmware_cb()

[Dawei Feng]

helper_firmware_cb() neglects to free the single-stage firmware image
after a successful async load, leading to a memory leak in the USB
firmware-download path.

Fix this memory leak by calling release_firmware() immediately after
lbs_fw_loaded() returns.

The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available. Manual inspection confirms that the bug is still present in
the current wireless tree.

An x86_64 allyesconfig build showed no new warnings. As we do not have
compatible Libertas USB hardware for exercising this firmware-download
path, no runtime testing was able to be performed.

Fixes: 1dfba3060fe7 ("libertas: move firmware lifetime handling to firmware.c")
Cc: stable at vger.kernel.org
Signed-off-by: Dawei Feng <dawei.feng at seu.edu.cn>
---
 drivers/net/wireless/marvell/libertas/firmware.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/wireless/marvell/libertas/firmware.c b/drivers/net/wireless/marvell/libertas/firmware.c
index f124110944b7..9bf7d4c207b9 100644
--- a/drivers/net/wireless/marvell/libertas/firmware.c
+++ b/drivers/net/wireless/marvell/libertas/firmware.c
@@ -78,6 +78,7 @@ static void helper_firmware_cb(const struct firmware *firmware, void *context)
 	} else {
 		/* No main firmware needed for this helper --> success! */
 		lbs_fw_loaded(priv, 0, firmware, NULL);
+		release_firmware(firmware);
 	}
 }
 
-- 
2.34.1