DF-4771

intel_dp_add_mst_connector error path leaks the allocated intel_connector (drm_connector_cleanup without kfree)

Summary

err: label runs drm_connector_cleanup but never kfrees the :451 allocation (the :462-464 init-failure path correctly frees). Reachable on attach_encoder failure or path-property blob ENOMEM during hub plug-in storms - one kzalloc-sized leak per failed add. One-line kfree fix. i915+MST hw-gated.

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Severity: Low
Status: new
Bucket: Base system — drivers
Confidence: certain
Pass: 2 · GLM 5.3 second pass
CVSS 3.1: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L
CWE: CWE-401
File: sys/dev/drm/i915/intel_dp_mst.c
Lines: 473-489
Area: dev
Discovered: 2026-09-23
Updated: 2026-09-23

Team triage

untriaged

priority: — · owner: —

PoC verification

untested

Status: untested
Reproduced: no
Impact: leak
Confidence: certain
Tested: 2026-09-23 12:50:02
Attempts: 0
Runtime: —
Code hash: —
Guest: —
Build cmd: —
Run cmd: —

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Fix verification

not_testable

Fix status: not_testable
Baseline reproduced: —
Patched reproduced: —
Confidence: certain
Tested: 2026-09-23 12:50:02
Runtime: —
Kernel: per-fix-DF-4771
fix.diff: findings/poc/DF-4771/fix.diff
Runner: df-bsd-reviewer

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PoC verification

Evidence pack

findings/poc/DF-4771 · 1 files

File	Type	Description	Size
verdict.json	file		872 B	view raw

Fix verification

not_testable

per-fix-DF-4771

Confirmed kernel references

Detail

Exploit chain

MST hub plug/unplug loop under ENOMEM pressure on path-blob alloc -> connector cleanup without kfree -> permanent kernel heap leak per cycle

Evidence (decisive lines)

findings/poc/DF-4771/ (this verdict)

Verdict

Source-certain error-path leak, hardware-gated: intel_dp_add_mst_connector err: label runs drm_connector_cleanup but never kfrees the intel_connector allocated at :451 (the :462-464 path correctly frees). Reachable on drm_connector_attach_encoder failure or drm_connector_set_path_property/blob ENOMEM during hub plug-in storms - one kzalloc-sized leak per failed add. No i915+MST on guest. One-line kfree fix.