diff options
| author | Dongliang Mu <mudongliangabcd@gmail.com> | 2022-01-22 15:44:59 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-28 10:56:52 +0200 |
| commit | 1f6ab281f218c3a2b789eb976c5b1ef67139680a (patch) | |
| tree | 5bd5e8c399fbe14b639b9b1b7ed4db08ee4f0cbe | |
| parent | 7c308ecae736fea5e68a2a54ae8fb1e0e4f5e4d0 (diff) | |
media: em28xx: initialize refcount before kref_get
commit c08eadca1bdfa099e20a32f8fa4b52b2f672236d upstream.
The commit 47677e51e2a4("[media] em28xx: Only deallocate struct
em28xx after finishing all extensions") adds kref_get to many init
functions (e.g., em28xx_audio_init). However, kref_init is called too
late in em28xx_usb_probe, since em28xx_init_dev before will invoke
those init functions and call kref_get function. Then refcount bug
occurs in my local syzkaller instance.
Fix it by moving kref_init before em28xx_init_dev. This issue occurs
not only in dev but also dev->dev_next.
Fixes: 47677e51e2a4 ("[media] em28xx: Only deallocate struct em28xx after finishing all extensions")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[DP: drop changes related to dev->dev_next as second tuner functionality was added in 4.16]
Signed-off-by: Dragos-Marian Panait <dragos.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/media/usb/em28xx/em28xx-cards.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c index b736c027a0bd..23a9fe8d9d1e 100644 --- a/drivers/media/usb/em28xx/em28xx-cards.c +++ b/drivers/media/usb/em28xx/em28xx-cards.c @@ -3644,6 +3644,8 @@ static int em28xx_usb_probe(struct usb_interface *interface, goto err_free; } + kref_init(&dev->ref); + dev->devno = nr; dev->model = id->driver_info; dev->alt = -1; @@ -3730,8 +3732,6 @@ static int em28xx_usb_probe(struct usb_interface *interface, dev->dvb_xfer_bulk ? "bulk" : "isoc"); } - kref_init(&dev->ref); - request_modules(dev); /* |