media: platform: mtk-mdp3: Add missing check and free for ida_alloc

[ Upstream commit d00f592250782538cda87745607695b0fe27dcd4 ]

Add the check for the return value of the ida_alloc in order to avoid
NULL pointer dereference.
Moreover, free allocated "ctx->id" if mdp_m2m_open fails later in order
to avoid memory leak.

Fixes: 61890ccaefaf ("media: platform: mtk-mdp3: add MediaTek MDP3 driver")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-m2m.c b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-m2m.c
index 5f74ea3..8612a48 100644 (file)
--- a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-m2m.c
+++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-m2m.c
@@ -566,7 +566,11 @@ static int mdp_m2m_open(struct file *file)
                goto err_free_ctx;
        }
 
-       ctx->id = ida_alloc(&mdp->mdp_ida, GFP_KERNEL);
+       ret = ida_alloc(&mdp->mdp_ida, GFP_KERNEL);
+       if (ret < 0)
+               goto err_unlock_mutex;
+       ctx->id = ret;
+
        ctx->mdp_dev = mdp;
 
        v4l2_fh_init(&ctx->fh, vdev);
@@ -617,6 +621,8 @@ err_release_handler:
        v4l2_fh_del(&ctx->fh);
 err_exit_fh:
        v4l2_fh_exit(&ctx->fh);
+       ida_free(&mdp->mdp_ida, ctx->id);
+err_unlock_mutex:
        mutex_unlock(&mdp->m2m_lock);
 err_free_ctx:
        kfree(ctx);