BUG: soft lockup - CPU#20 stuck for XXs! and call trace shows in vm_is_stack()

Issue

BUG: soft lockup occurring with call trace showing vm_is_stack(). Here is an example:

BUG: soft lockup - CPU#XX stuck for 2Xs! [proc:PID]
Call Trace:
[<ffffffff81173ef7>] vm_is_stack+0x87/0x100
[<ffffffff8122c625>] show_map_vma+0x255/0x2e0
[<ffffffff8122d02d>] show_smap+0x9d/0x270
[<ffffffff8160a229>] ? schedule+0x29/0x70
[<ffffffff8160bd25>] ? rwsem_down_read_failed+0xf5/0x165
[<ffffffff8122dd10>] ? clear_refs_pte_range+0x180/0x180
[<ffffffff8122d213>] show_pid_smap+0x13/0x20
[<ffffffff811ea5ea>] seq_read+0xfa/0x3a0
[<ffffffff811c6b6c>] vfs_read+0x9c/0x170
[<ffffffff811c7698>] SyS_read+0x58/0xb0
[<ffffffff81614e29>] system_call_fastpath+0x16/0x1b