Medium [CVE-2026-52965] Fix ttm_bo_swapout infinite LRU walk on swapout failure
This medium-severity Red Hat Linux advisory covers CVE-2026-52965 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat package: kernel-rt.
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Summary
In the Linux kernel, the following vulnerability has been resolved: drm/ttm: Fix ttm_bo_swapout() infinite LRU walk on swapout failure When ttm_tt_swapout() fails, the current code calls ttm_resource_add_bulk_move() followed by ttm_resource_move_to_lru_tail() to restore the resource's bulk_move membership.
However, ttm_resource_move_to_lru_tail() places the resource at the tail of the LRU list which, relative to the walk cursor's hitch node (placed immediately after the resource when it was yielded), puts the resource *in front of the* the hitch. The next list_for_each_entry_continue() from the hitch finds the same resource again, causing an infinite loop.
Fix by deferring del_bulk_move to the success path only. On the success path, TTM_TT_FLAG_SWAPPED has just been set by ttm_tt_swapout() but the resource is still tracked in the bulk_move range, so ttm_resource_del_bulk_move()'s!ttm_resource_unevictable() guard would incorrectly skip the removal.
Introduce ttm_resource_del_bulk_move_unevictable() which bypasses that guard. A flaw was found in the Linux kernel's TTM (Trusted Memory Manager) component.
When the ttm_tt_swapout() function fails, a resource is incorrectly added to the Least Recently Used (LRU) list. This misplacement can lead to an infinite loop during subsequent list processing, causing the system to become unresponsive.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 9 days ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 9 days ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 9 days ago·verify at source
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