From: Jiasheng Jiang <jiasheng@xxxxxxxxxxx> [ 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@xxxxxxxxxxx> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/media/platform/mediatek/mdp3/mtk-mdp3-m2m.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-m2m.c b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-m2m.c index 5f74ea3b7a524..8612a48bde10f 100644 --- 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 @@ static int mdp_m2m_open(struct file *file) 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); -- 2.39.2