Bug 2337113 (CVE-2024-57798)

Summary: CVE-2024-57798 kernel: drm/dp_mst: Ensure mst_primary pointer is valid in drm_dp_mst_handle_up_req()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-01-11 13:02:31 UTC 
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.
Comment 1 Avinash Hanwate 2025-01-13 07:25:18 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025011151-CVE-2024-57798-68b5@gregkh/T
Comment 3 errata-xmlrpc 2025-05-13 08:38:22 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2025:6966 https://access.redhat.com/errata/RHSA-2025:6966