| Message ID | 20220426052921.2088416-1-keitasuzuki.park@sslab.ics.keio.ac.jp |
|---|---|
| State | Accepted |
| Commit | 6b0d0477fce747d4137aa65856318b55fba72198 |
| Headers | show |
| Series | media: dvb-core: Fix double free in dvb_register_device() | expand |
diff --git a/drivers/media/dvb-core/dvbdev.c b/drivers/media/dvb-core/dvbdev.c index 675d877a67b2..4597af108f4d 100644 --- a/drivers/media/dvb-core/dvbdev.c +++ b/drivers/media/dvb-core/dvbdev.c @@ -332,6 +332,7 @@ static int dvb_create_media_entity(struct dvb_device *dvbdev, GFP_KERNEL); if (!dvbdev->pads) { kfree(dvbdev->entity); + dvbdev->entity = NULL; return -ENOMEM; } }
In function dvb_register_device() -> dvb_register_media_device() -> dvb_create_media_entity(), dvb->entity is allocated and initialized. If the initialization fails, it frees the dvb->entity, and return an error code. The caller takes the error code and handles the error by calling dvb_media_device_free(), which unregisters the entity and frees the field again if it is not NULL. As dvb->entity may not NULLed in dvb_create_media_entity() when the allocation of dvbdev->pad fails, a double free may occur. This may also cause an Use After free in media_device_unregister_entity(). Fix this by storing NULL to dvb->entity when it is freed. Fixes: fcd5ce4b3936 ("media: dvb-core: fix a memory leak bug") Cc: stable@vger.kernel.org Cc: Wenwen Wang <wenwen@cs.uga.edu> Signed-off-by: Keita Suzuki <keitasuzuki.park@sslab.ics.keio.ac.jp> --- drivers/media/dvb-core/dvbdev.c | 1 + 1 file changed, 1 insertion(+)