4.18-stable review patch. If anyone has any objections, please let me know.
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From: Nicholas Kazlauskas nicholas.kazlauskas@amd.com
[ Upstream commit dddc0557e3a02499ce336b1e2e67f5afaecccc80 ]
[Why]
A null pointer deference can occur if crtc is null in amdgpu_dm_crtc_handle_crc_irq. This can happen if get_crtc_by_otg_inst returns NULL during dm_crtc_high_irq, leading to a hang in some IGT test cases.
[How]
Check that CRTC is non-null before accessing its fields.
Signed-off-by: Nicholas Kazlauskas nicholas.kazlauskas@amd.com Reviewed-by: Sun peng Li Sunpeng.Li@amd.com Acked-by: Leo Li sunpeng.li@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crc.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crc.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crc.c @@ -98,10 +98,16 @@ int amdgpu_dm_crtc_set_crc_source(struct */ void amdgpu_dm_crtc_handle_crc_irq(struct drm_crtc *crtc) { - struct dm_crtc_state *crtc_state = to_dm_crtc_state(crtc->state); - struct dc_stream_state *stream_state = crtc_state->stream; + struct dm_crtc_state *crtc_state; + struct dc_stream_state *stream_state; uint32_t crcs[3];
+ if (crtc == NULL) + return; + + crtc_state = to_dm_crtc_state(crtc->state); + stream_state = crtc_state->stream; + /* Early return if CRC capture is not enabled. */ if (!crtc_state->crc_enabled) return;