Description
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.
Affected products
- Linux / Linuxfc5d96670eb2540d2572a14351e82ffe45d5ac11 – 0124a09e3e5f5f6080efe9663b27af27933f8382
- Linux / Linuxfc5d96670eb2540d2572a14351e82ffe45d5ac11 – b2ed01e7ad3de80333e9b962a44024b094bc0b2b
- Linux / Linux6.13 – 6.13
- Linux / Linux0 – 6.13
- Linux / Linux7.0.10 – 7.0.*
- Linux / Linux7.1 – *