CVE-2022-48675

In the Linux kernel, the following vulnerability has been resolved:
IB/core: Fix a nested dead lock as part of ODP flow Fix a nested dead lock
as part of ODP flow by using mmput_async(). From the below call trace [1]
can see that calling mmput() once we have the umem_odp->umem_mutex locked
as required by ib_umem_odp_map_dma_and_lock() might trigger in the same
task the exit_mmap()->__mmu_notifier_release()->mlx5_ib_invalidate_range()
which may dead lock when trying to lock the same mutex. Moving to use
mmput_async() will solve the problem as the above exit_mmap() flow will be
called in other task and will be executed once the lock will be available.
[1] [64843.077665] task:kworker/u133:2 state:D stack: 0 pid:80906 ppid: 2
flags:0x00004000 [64843.077672] Workqueue: mlx5_ib_page_fault
mlx5_ib_eqe_pf_action [mlx5_ib] [64843.077719] Call Trace: [64843.077722]
<TASK> [64843.077724] __schedule+0x23d/0x590 [64843.077729]
schedule+0x4e/0xb0 [64843.077735] schedule_preempt_disabled+0xe/0x10
[64843.077740] __mutex_lock.constprop.0+0x263/0x490 [64843.077747]
__mutex_lock_slowpath+0x13/0x20 [64843.077752] mutex_lock+0x34/0x40
[64843.077758] mlx5_ib_invalidate_range+0x48/0x270 [mlx5_ib] [64843.077808]
__mmu_notifier_release+0x1a4/0x200 [64843.077816] exit_mmap+0x1bc/0x200
[64843.077822] ? walk_page_range+0x9c/0x120 [64843.077828] ?
__cond_resched+0x1a/0x50 [64843.077833] ? mutex_lock+0x13/0x40
[64843.077839] ? uprobe_clear_state+0xac/0x120 [64843.077860]
mmput+0x5f/0x140 [64843.077867] ib_umem_odp_map_dma_and_lock+0x21b/0x580
[ib_core] [64843.077931] pagefault_real_mr+0x9a/0x140 [mlx5_ib]
[64843.077962] pagefault_mr+0xb4/0x550 [mlx5_ib] [64843.077992]
pagefault_single_data_segment.constprop.0+0x2ac/0x560 [mlx5_ib]
[64843.078022] mlx5_ib_eqe_pf_action+0x528/0x780 [mlx5_ib] [64843.078051]
process_one_work+0x22b/0x3d0 [64843.078059] worker_thread+0x53/0x410
[64843.078065] ? process_one_work+0x3d0/0x3d0 [64843.078073]
kthread+0x12a/0x150 [64843.078079] ? set_kthread_struct+0x50/0x50
[64843.078085] ret_from_fork+0x22/0x30 [64843.078093] </TASK>