From: Keita Suzuki <keitasuzuki.park@sslab.ics.keio.ac.jp> mainline inclusion from mainline-v6.2-rc1 commit 6b0d0477fce747d4137aa65856318b55fba72198 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I635IG CVE: CVE-2022-45884 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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. Link: https://lore.kernel.org/linux-media/20220426052921.2088416-1-keitasuzuki.par... 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> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org> Signed-off-by: liwei <liwei728@huawei.com> --- drivers/media/dvb-core/dvbdev.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/media/dvb-core/dvbdev.c b/drivers/media/dvb-core/dvbdev.c index 97bbf10b392f..0146a96b0839 100644 --- a/drivers/media/dvb-core/dvbdev.c +++ b/drivers/media/dvb-core/dvbdev.c @@ -345,6 +345,7 @@ static int dvb_create_media_entity(struct dvb_device *dvbdev, GFP_KERNEL); if (!dvbdev->pads) { kfree(dvbdev->entity); + dvbdev->entity = NULL; return -ENOMEM; } } -- 2.25.1