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| author | Luca Coelho <luciano.coelho@intel.com> | 2026-09-08 13:06:51 +0300 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2026-09-15 11:14:13 +0300 |
| commit | ee415ce8cba154d07d02a6d2fbb27ff518264c3a (patch) | |
| tree | e02d7ae7da26a087f7a702c96fe7238fc7ccf6c9 | |
| parent | fd73f4a6659897191fa0d40695fe370925dd3780 (diff) | |
| download | linux-next-ee415ce8cba154d07d02a6d2fbb27ff518264c3a.tar.gz linux-next-ee415ce8cba154d07d02a6d2fbb27ff518264c3a.zip | |
drm/i915/display: check configuration index before shifting
The calc_allowed_config_filter() function passes the return value of
iter_pos_to_idx() directly to BIT(), but the helper can return -1 for
an invalid iterator.
The iterator already rejects negative indices before doing a
configuration, so this should not matter in normal flows. In any
case, for robustness, check the index explicitly and warn if it is
negative, avoiding an undefined shift.
Fixes: 39e30bdf2f92 ("drm/i915/dp_link_caps: Add link configuration iterator")
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260908100659.113555-1-luciano.coelho@intel.com
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
(cherry picked from commit fe05cb9b9fb0ecc10409c4c6133257214b6cd8c8)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp_link_caps.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_caps.c b/drivers/gpu/drm/i915/display/intel_dp_link_caps.c index 7b6cc6055da8..98657aa4d3d5 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_caps.c +++ b/drivers/gpu/drm/i915/display/intel_dp_link_caps.c @@ -426,12 +426,15 @@ calc_allowed_config_filter(struct intel_dp_link_caps *link_caps, const struct intel_dp_link_config *forced_params) { struct intel_dp_link_caps_filter allowed_configs = INTEL_DP_LINK_CAPS_FILTER_NONE; + struct intel_display *display = to_intel_display(link_caps->dp); struct intel_dp_link_caps_order order = bw_desc_config_order(); struct intel_dp_link_caps_iter iter; struct intel_dp_link_config config; iter_start(&iter, link_caps, order, enabled_configs); for_each_dp_link_config(&iter, &config) { + int config_idx; + if (forced_params->rate && forced_params->rate != config.rate) continue; @@ -446,7 +449,11 @@ calc_allowed_config_filter(struct intel_dp_link_caps *link_caps, if (config.lane_count > max_limits->lane_count) continue; - allowed_configs.config_mask |= BIT(iter_pos_to_idx(link_caps, order, iter.pos)); + config_idx = iter_pos_to_idx(link_caps, order, iter.pos); + if (drm_WARN_ON(display->drm, config_idx < 0)) + continue; + + allowed_configs.config_mask |= BIT(config_idx); } intel_dp_link_caps_iter_end(&iter); |