This is a note to let you know that I've just added the patch titled
media: cec: cec-api: add locking in cec_release()
to the 5.4-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-cec-api-add-locking-in-cec_release.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 067f3cf836a912899497f300cf6547b62d702e22
Author: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Date: Fri Feb 23 12:25:55 2024 +0000
media: cec: cec-api: add locking in cec_release()
[ Upstream commit 42bcaacae924bf18ae387c3f78c202df0b739292 ]
When cec_release() uses fh->msgs it has to take fh->lock,
otherwise the list can get corrupted.
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/cec-api.c b/drivers/media/cec/cec-api.c
index ed75636a6fb34..90e90234f5bd8 100644
--- a/drivers/media/cec/cec-api.c
+++ b/drivers/media/cec/cec-api.c
@@ -652,6 +652,8 @@ static int cec_release(struct inode *inode, struct file *filp)
list_del(&data->xfer_list);
}
mutex_unlock(&adap->lock);
+
+ mutex_lock(&fh->lock);
while (!list_empty(&fh->msgs)) {
struct cec_msg_entry *entry =
list_first_entry(&fh->msgs, struct cec_msg_entry, list);
@@ -669,6 +671,7 @@ static int cec_release(struct inode *inode, struct file *filp)
kfree(entry);
}
}
+ mutex_unlock(&fh->lock);
kfree(fh);
cec_put_device(devnode);
