From e559765186ac6da502bdbe23490a7eda2639de6e Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 14 Dec 2020 12:54:47 +0100 Subject: [PATCH] media: allegro: Fix use after free on error [ Upstream commit ce814ad4bb52bfc7c0472e6da0aa742ab88f4361 ] The "channel" is added to the "dev->channels" but then if v4l2_m2m_ctx_init() fails then we free "channel" but it's still on the list so it could lead to a use after free. Let's not add it to the list until after v4l2_m2m_ctx_init() succeeds. Fixes: cc62c74749a3 ("media: allegro: add missed checks in allegro_open()") Signed-off-by: Dan Carpenter Reviewed-by: Michael Tretter Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/staging/media/allegro-dvt/allegro-core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/staging/media/allegro-dvt/allegro-core.c b/drivers/staging/media/allegro-dvt/allegro-core.c index 9f718f4..6404511 100644 --- a/drivers/staging/media/allegro-dvt/allegro-core.c +++ b/drivers/staging/media/allegro-dvt/allegro-core.c @@ -2483,8 +2483,6 @@ static int allegro_open(struct file *file) INIT_LIST_HEAD(&channel->buffers_reference); INIT_LIST_HEAD(&channel->buffers_intermediate); - list_add(&channel->list, &dev->channels); - channel->fh.m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, channel, allegro_queue_init); @@ -2493,6 +2491,7 @@ static int allegro_open(struct file *file) goto error; } + list_add(&channel->list, &dev->channels); file->private_data = &channel->fh; v4l2_fh_add(&channel->fh); -- 2.7.4