CVE-2024-57798: drm/dp_mst: Ensure mst_primary pointer is valid in drm_dp_mst_handle_up_req()

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-01-11 · updated 2026-06-17
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: drm/dp_mst: Ensure mst_primary pointer is valid in drm_dp_mst_handle_up_req() While receiving an MST up request message from one thread in drm_dp_mst_handle_up_req(), the MST topology could be removed from another thread via drm_dp_mst_topology_mgr_set_mst(false), freeing mst_primary and setting drm_dp_mst_topology_mgr::mst_primary to NULL. This could lead to a NULL deref/use-after-free of mst_primary in drm_dp_mst_handle_up_req(). Avoid the above by holding a reference for mst_primary in drm_dp_mst_handle_up_req() while it's used. v2: Fix kfreeing the request if getting an mst_primary reference fails.

Affected products

Linux kernel: before 6.1.123; from 6.2 before 6.6.69; from 6.7 before 6.12.8; 6.13-rc1 — fixed in 6.1.123, 6.12.8, 6.6.69

How to fix

Upgrade to a fixed version: Linux kernel 6.1.123, 6.12.8, 6.6.69. Check the vendor advisory for mitigations.

References

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