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authorNikita Zhandarovich <n.zhandarovich@fintech.ru>2023-04-18 07:04:30 -0700
committerJoonas Lahtinen <joonas.lahtinen@linux.intel.com>2023-05-11 14:11:59 +0300
commit0ff80028e2702c7c3d78b69705dc47c1ccba8c39 (patch)
treea750911e1b85077fa0f81541e1b0d79487b32aa7 /drivers
parenta41d985902c153c31c616fe183cf2ee331e95ecb (diff)
drm/i915/dp: prevent potential div-by-zero
drm_dp_dsc_sink_max_slice_count() may return 0 if something goes wrong on the part of the DSC sink and its DPCD register. This null value may be later used as a divisor in intel_dsc_compute_params(), which will lead to an error. In the unlikely event that this issue occurs, fix it by testing the return value of drm_dp_dsc_sink_max_slice_count() against zero. Found by Linux Verification Center (linuxtesting.org) with static analysis tool SVACE. Fixes: a4a157777c80 ("drm/i915/dp: Compute DSC pipe config in atomic check") Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20230418140430.69902-1-n.zhandarovich@fintech.ru (cherry picked from commit 51f7008239de011370c5067bbba07f0207f06b72) Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpu/drm/i915/display/intel_dp.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index f0bace9d98a1..529ee22be872 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1601,6 +1601,11 @@ int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
pipe_config->dsc.slice_count =
drm_dp_dsc_sink_max_slice_count(intel_dp->dsc_dpcd,
true);
+ if (!pipe_config->dsc.slice_count) {
+ drm_dbg_kms(&dev_priv->drm, "Unsupported Slice Count %d\n",
+ pipe_config->dsc.slice_count);
+ return -EINVAL;
+ }
} else {
u16 dsc_max_output_bpp = 0;
u8 dsc_dp_slice_count;