[PATCH] wifi: iwlegacy: add missing mutex protection in il3945_store_measurement()

[Ziyi Guo]

il3945_store_measurement() calls il3945_get_measurement() which internally
calls il_send_cmd_sync() without holding il->mutex. However,
il_send_cmd_sync() has lockdep_assert_held(&il->mutex) indicating that
callers must hold this lock.

Other sysfs store functions in the same file properly acquire the mutex:
- il3945_store_flags() acquires mutex at 3945-mac.c:3110
- il3945_store_filter_flags() acquires mutex at 3945-mac.c:3144

Add mutex_lock()/mutex_unlock() around the il3945_get_measurement() call
in the sysfs store function to fix the missing lock protection.

Signed-off-by: Ziyi Guo <n7l8m4@xxxxxxxxxxxxxxxxxx>
---
 drivers/net/wireless/intel/iwlegacy/3945-mac.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/wireless/intel/iwlegacy/3945-mac.c b/drivers/net/wireless/intel/iwlegacy/3945-mac.c
index 104748fcdc33..54991f31c52c 100644
--- a/drivers/net/wireless/intel/iwlegacy/3945-mac.c
+++ b/drivers/net/wireless/intel/iwlegacy/3945-mac.c
@@ -3224,7 +3224,9 @@ il3945_store_measurement(struct device *d, struct device_attribute *attr,
 
 	D_INFO("Invoking measurement of type %d on " "channel %d (for '%s')\n",
 	       type, params.channel, buf);
+	mutex_lock(&il->mutex);
 	il3945_get_measurement(il, &params, type);
+	mutex_unlock(&il->mutex);
 
 	return count;
 }
-- 
2.34.1