Re: [syzbot] [media?] INFO: task hung in cec_claim_log_addrs

[Hillf Danton <hdanton@sina.com>]

On Tue, 20 Feb 2024 22:13:24 -0800
> HEAD commit:    83d49ede4b18 Merge branch 'for-next/core' into for-kernelci
> git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11ddc734180000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git  for-kernelci

--- x/drivers/media/cec/core/cec-adap.c
+++ y/drivers/media/cec/core/cec-adap.c
@@ -1575,7 +1575,6 @@ unconfigure:
 	cec_adap_unconfigure(adap);
 	adap->is_configuring = false;
 	adap->must_reconfigure = false;
-	adap->kthread_config = NULL;
 	complete(&adap->config_completion);
 	mutex_unlock(&adap->lock);
 	return 0;
@@ -1592,6 +1591,8 @@ static void cec_claim_log_addrs(struct c
 	if (WARN_ON(adap->is_configuring || adap->is_configured))
 		return;
 
+	if (adap->kthread_config)
+		return;
 	init_completion(&adap->config_completion);
 
 	/* Ready to kick off the thread */
@@ -1605,6 +1606,7 @@ static void cec_claim_log_addrs(struct c
 		mutex_unlock(&adap->lock);
 		wait_for_completion(&adap->config_completion);
 		mutex_lock(&adap->lock);
+		adap->kthread_config = NULL;
 	}
 }
 
--