drm: vc4: Fix possible null pointer dereference

[ Upstream commit c534b63bede6cb987c2946ed4d0b0013a52c5ba7 ]

In vc4_hdmi_audio_init() of_get_address() may return
NULL which is later dereferenced. Fix this bug by adding NULL check.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: bb7d78568814 ("drm/vc4: Add HDMI audio support")
Signed-off-by: Aleksandr Mishin <amishin@t-argos.ru>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240409075622.11783-1-amishin@t-argos.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 88aa00a1891b350658707e8cf24614330753d5c6..86d77794d8392c7e47270fbb9de2fc0f460140dd 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -1506,6 +1506,8 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)
                index = 1;
 
        addr = of_get_address(dev->of_node, index, NULL, NULL);
+       if (!addr)
+               return -EINVAL;
 
        vc4_hdmi->audio.dma_data.addr = be32_to_cpup(addr) + mai_data->offset;
        vc4_hdmi->audio.dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;