Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

drm/ttm: Drop tt->restore after successful restore

ttm_pool_restore_and_alloc() can successfully complete the restore process via ttm_pool_restore_commit(), but tt->restore is not dropped afterward. As a result, subsequent backup/restore flows observe what appears to be a completed restore, while in reality shmem handles are still installed in tt->pages, leading to the stack trace below.

Fix this by freeing and dropping tt->restore in ttm_pool_restore_and_alloc() upon successful completion of the restore.

20545 [  309.784531] RIP: 0010:sg_alloc_append_table_from_pages+0x38c/0x490 20547 [  309.809570] RSP: 0018:ffffc9000623b838 EFLAGS: 00010206 20548 [  309.814827] RAX: 0000000000001000 RBX: ffff88816e42a160 RCX: 0000000000000000 20549 [  309.821986] RDX: 0000000000002000 RSI: 0000000000000003 RDI: 0000000000001000 20550 [  309.829147] RBP: ffff88816e42a168 R08: 0000000000000002 R09: 000000007ffff000 20551 [  309.836310] R10: ffffc9000623b928 R11: 0000000000000000 R12: 000000007ffff000 20552 [  309.843471] R13: ffff88815ba5a100 R14: 0000000000000000 R15: 0000000000000001 20553 [  309.850634] FS:  00007f9ff305e700(0000) GS:ffff888276c94000(0000) knlGS:0000000000000000 20554 [  309.858749] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 20555 [  309.864519] CR2: 00007f9fca701000 CR3: 00000001565e2005 CR4: 0000000008f70ef0 20556 [  309.871678] PKRU: 55555558 20557 [  309.874403] Call Trace: 20558 [  309.87…