Patch "media: cec: core: avoid recursive cec_claim_log_addrs" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    media: cec: core: avoid recursive cec_claim_log_addrs

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     media-cec-core-avoid-recursive-cec_claim_log_addrs.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 3040141a5aa4ec469eadeef717f1604c757cda2e
Author: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Date:   Thu Feb 22 16:17:33 2024 +0000

    media: cec: core: avoid recursive cec_claim_log_addrs
    
    [ Upstream commit 47c82aac10a6954d68f29f10d9758d016e8e5af1 ]
    
    Keep track if cec_claim_log_addrs() is running, and return -EBUSY
    if it is when calling CEC_ADAP_S_LOG_ADDRS.
    
    This prevents a case where cec_claim_log_addrs() could be called
    while it was still in progress.
    
    Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
    Reported-by: Yang, Chenyuan <cy54@xxxxxxxxxxxx>
    Closes: https://lore.kernel.org/linux-media/PH7PR11MB57688E64ADE4FE82E658D86DA09EA@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
    Fixes: ca684386e6e2 ("[media] cec: add HDMI CEC framework (api)")
    Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/media/cec/core/cec-adap.c b/drivers/media/cec/core/cec-adap.c
index 99c14942f2813..c15abee3e9bc4 100644
--- a/drivers/media/cec/core/cec-adap.c
+++ b/drivers/media/cec/core/cec-adap.c
@@ -1547,9 +1547,12 @@ static int cec_config_thread_func(void *arg)
  */
 static void cec_claim_log_addrs(struct cec_adapter *adap, bool block)
 {
-	if (WARN_ON(adap->is_configuring || adap->is_configured))
+	if (WARN_ON(adap->is_claiming_log_addrs ||
+		    adap->is_configuring || adap->is_configured))
 		return;
 
+	adap->is_claiming_log_addrs = true;
+
 	init_completion(&adap->config_completion);
 
 	/* Ready to kick off the thread */
@@ -1564,6 +1567,7 @@ static void cec_claim_log_addrs(struct cec_adapter *adap, bool block)
 		wait_for_completion(&adap->config_completion);
 		mutex_lock(&adap->lock);
 	}
+	adap->is_claiming_log_addrs = false;
 }
 
 /*
diff --git a/drivers/media/cec/core/cec-api.c b/drivers/media/cec/core/cec-api.c
index d64bb716f9c68..3ef9153443044 100644
--- a/drivers/media/cec/core/cec-api.c
+++ b/drivers/media/cec/core/cec-api.c
@@ -178,7 +178,7 @@ static long cec_adap_s_log_addrs(struct cec_adapter *adap, struct cec_fh *fh,
 			   CEC_LOG_ADDRS_FL_ALLOW_RC_PASSTHRU |
 			   CEC_LOG_ADDRS_FL_CDC_ONLY;
 	mutex_lock(&adap->lock);
-	if (!adap->is_configuring &&
+	if (!adap->is_claiming_log_addrs && !adap->is_configuring &&
 	    (!log_addrs.num_log_addrs || !adap->is_configured) &&
 	    !cec_is_busy(adap, fh)) {
 		err = __cec_s_log_addrs(adap, &log_addrs, block);
diff --git a/include/media/cec.h b/include/media/cec.h
index 9c007f83569aa..ffd17371302ca 100644
--- a/include/media/cec.h
+++ b/include/media/cec.h
@@ -247,6 +247,7 @@ struct cec_adapter {
 	u16 phys_addr;
 	bool needs_hpd;
 	bool is_enabled;
+	bool is_claiming_log_addrs;
 	bool is_configuring;
 	bool must_reconfigure;
 	bool is_configured;