I hit this a few days ago. I'm not 100% what kernel it was running, but I'm pretty sure it was a post 4.5 kernel from this merge window.
WARNING: CPU: 2 PID: 28919 at kernel/locking/lockdep.c:3198 __lock_acquire+0x74d/0x1c60 DEBUG_LOCKS_WARN_ON(class_idx > MAX_LOCKDEP_KEYS) CPU: 2 PID: 28919 Comm: trinity-c30 Not tainted 4.5.0-think+ #6 ffffffffba141ccd 000000001ded0b05 ffff8803e4b67480 ffffffffba575c0b ffff8803e4b674f8 0000000000000000 ffff8803e4b674c8 ffffffffba0b3eb1 ffff88045fbe37c0 00000c7ee4b674e0 ffffed007c96ce9b 0000000000000000 Call Trace: [<ffffffffba141ccd>] ? __lock_acquire+0x74d/0x1c60 [<ffffffffba575c0b>] dump_stack+0x68/0x9d [<ffffffffba0b3eb1>] __warn+0x111/0x130 [<ffffffffba0b3f84>] warn_slowpath_fmt+0xb4/0xf0 [<ffffffffba0b3ed0>] ? __warn+0x130/0x130 [<ffffffffba1409cb>] ? mark_lock+0x45b/0x800 [<ffffffffba141ccd>] __lock_acquire+0x74d/0x1c60 [<ffffffffba1611aa>] ? debug_lockdep_rcu_enabled.part.18+0x1a/0x30 [<ffffffffba1611f5>] ? debug_lockdep_rcu_enabled+0x35/0x40 [<ffffffffba141580>] ? debug_check_no_locks_freed+0x1b0/0x1b0 [<ffffffffba141580>] ? debug_check_no_locks_freed+0x1b0/0x1b0 [<ffffffffbad456b2>] ? _raw_spin_unlock_irq+0x32/0x50 [<ffffffffba0f77aa>] ? preempt_count_sub+0x1a/0x130 [<ffffffffba143dcf>] lock_acquire+0xcf/0x2a0 [<ffffffffba12eba8>] ? finish_wait+0x68/0xc0 [<ffffffffbad4541c>] _raw_spin_lock_irqsave+0x4c/0x90 [<ffffffffba12eba8>] ? finish_wait+0x68/0xc0 [<ffffffffba12eba8>] finish_wait+0x68/0xc0 [<ffffffffba2a6453>] shmem_fault+0x323/0x390 [<ffffffffba2a6130>] ? shmem_file_splice_read+0x720/0x720 [<ffffffffba12f180>] ? prepare_to_wait_event+0x200/0x200 [<ffffffffba1611f5>] ? debug_lockdep_rcu_enabled+0x35/0x40 [<ffffffffba14063f>] ? mark_lock+0xcf/0x800 [<ffffffffba2c3eb8>] __do_fault+0x138/0x2e0 [<ffffffffba2c3d80>] ? wp_page_copy.isra.79+0x850/0x850 [<ffffffffba2c9a5b>] handle_mm_fault+0x42b/0x2400 [<ffffffffba141e38>] ? __lock_acquire+0x8b8/0x1c60 [<ffffffffba14063f>] ? mark_lock+0xcf/0x800 [<ffffffffba1611aa>] ? debug_lockdep_rcu_enabled.part.18+0x1a/0x30 [<ffffffffba035e36>] ? native_sched_clock+0x66/0x160 [<ffffffffba2c9630>] ? copy_page_range+0xec0/0xec0 [<ffffffffba0f7a9e>] ? ___might_sleep.part.86+0x1de/0x2c0 [<ffffffffba2bd8ad>] ? vmacache_find+0xed/0x140 [<ffffffffba0722d2>] __do_page_fault+0x1d2/0x5a0 [<ffffffffba4dd0d0>] ? SyS_shmget+0x100/0x100 [<ffffffffba0726c0>] do_page_fault+0x20/0x70 [<ffffffffbad469d7>] ? native_iret+0x7/0x7 [<ffffffffbad47cdf>] page_fault+0x1f/0x30 [<ffffffffba4dd0d0>] ? SyS_shmget+0x100/0x100 [<ffffffffba58c112>] ? copy_user_enhanced_fast_string+0x2/0x10 [<ffffffffba4dcb7f>] ? shmctl_nolock.constprop.24+0x5ff/0x690 [<ffffffffba4dc847>] ? shmctl_nolock.constprop.24+0x2c7/0x690 [<ffffffffba141580>] ? debug_check_no_locks_freed+0x1b0/0x1b0 [<ffffffffba4dc580>] ? newseg+0x5e0/0x5e0 [<ffffffffba5a7247>] ? debug_smp_processor_id+0x17/0x20 [<ffffffffba0f7849>] ? preempt_count_sub+0xb9/0x130 [<ffffffffba4dd0d0>] ? SyS_shmget+0x100/0x100 [<ffffffffba4dd412>] SyS_shmctl+0x342/0x490 [<ffffffffba003aa4>] do_syscall_64+0xf4/0x240 [<ffffffffbad4605a>] entry_SYSCALL64_slow_path+0x25/0x25 ---[ end trace 638c142c3cb9ddb1 ]--- ================================================================== BUG: KASAN: stack-out-of-bounds in do_raw_spin_trylock+0x14/0x70 at addr ffff8803ee067ba0 Read of size 4 by task trinity-c30/28919 page:ffffea000fb819c0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x8000000000000000() page dumped because: kasan: bad access detected CPU: 2 PID: 28919 Comm: trinity-c30 Tainted: G W 4.5.0-think+ #6 ffff8803e4b678b0 000000001ded0b05 ffff8803e4b676a0 ffffffffba575c0b ffff8803e4b67738 ffff8803ee067ba0 ffff8803e4b67728 ffffffffba308cb3 0000000000000003 dffffc0000000000 0000000000000082 0000000000000001 Call Trace: [<ffffffffba575c0b>] dump_stack+0x68/0x9d [<ffffffffba308cb3>] kasan_report_error+0x503/0x530 [<ffffffffbad456b2>] ? _raw_spin_unlock_irq+0x32/0x50 [<ffffffffba0f77aa>] ? preempt_count_sub+0x1a/0x130 [<ffffffffba309278>] kasan_report+0x58/0x60 [<ffffffffba149ca4>] ? do_raw_spin_trylock+0x14/0x70 [<ffffffffba307a8a>] __asan_load4+0x6a/0x70 [<ffffffffba149ca4>] do_raw_spin_trylock+0x14/0x70 [<ffffffffbad45424>] _raw_spin_lock_irqsave+0x54/0x90 [<ffffffffba12eba8>] ? finish_wait+0x68/0xc0 [<ffffffffba12eba8>] finish_wait+0x68/0xc0 [<ffffffffba2a6453>] shmem_fault+0x323/0x390 [<ffffffffba2a6130>] ? shmem_file_splice_read+0x720/0x720 [<ffffffffba12f180>] ? prepare_to_wait_event+0x200/0x200 [<ffffffffba1611f5>] ? debug_lockdep_rcu_enabled+0x35/0x40 [<ffffffffba14063f>] ? mark_lock+0xcf/0x800 [<ffffffffba2c3eb8>] __do_fault+0x138/0x2e0 [<ffffffffba2c3d80>] ? wp_page_copy.isra.79+0x850/0x850 [<ffffffffba2c9a5b>] handle_mm_fault+0x42b/0x2400 [<ffffffffba141e38>] ? __lock_acquire+0x8b8/0x1c60 [<ffffffffba14063f>] ? mark_lock+0xcf/0x800 [<ffffffffba1611aa>] ? debug_lockdep_rcu_enabled.part.18+0x1a/0x30 [<ffffffffba035e36>] ? native_sched_clock+0x66/0x160 [<ffffffffba2c9630>] ? copy_page_range+0xec0/0xec0 [<ffffffffba0f7a9e>] ? ___might_sleep.part.86+0x1de/0x2c0 [<ffffffffba2bd8ad>] ? vmacache_find+0xed/0x140 [<ffffffffba0722d2>] __do_page_fault+0x1d2/0x5a0 [<ffffffffba4dd0d0>] ? SyS_shmget+0x100/0x100 [<ffffffffba0726c0>] do_page_fault+0x20/0x70 [<ffffffffbad469d7>] ? native_iret+0x7/0x7 [<ffffffffbad47cdf>] page_fault+0x1f/0x30 [<ffffffffba4dd0d0>] ? SyS_shmget+0x100/0x100 [<ffffffffba58c112>] ? copy_user_enhanced_fast_string+0x2/0x10 [<ffffffffba4dcb7f>] ? shmctl_nolock.constprop.24+0x5ff/0x690 [<ffffffffba4dc847>] ? shmctl_nolock.constprop.24+0x2c7/0x690 [<ffffffffba141580>] ? debug_check_no_locks_freed+0x1b0/0x1b0 [<ffffffffba4dc580>] ? newseg+0x5e0/0x5e0 [<ffffffffba5a7247>] ? debug_smp_processor_id+0x17/0x20 [<ffffffffba0f7849>] ? preempt_count_sub+0xb9/0x130 [<ffffffffba4dd0d0>] ? SyS_shmget+0x100/0x100 [<ffffffffba4dd412>] SyS_shmctl+0x342/0x490 [<ffffffffba003aa4>] do_syscall_64+0xf4/0x240 [<ffffffffbad4605a>] entry_SYSCALL64_slow_path+0x25/0x25 Memory state around the buggy address: ffff8803ee067a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8803ee067b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8803ee067b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff8803ee067c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8803ee067c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ------------[ cut here ]------------ WARNING: CPU: 2 PID: 28919 at lib/list_debug.c:59 __list_del_entry+0xdc/0x100 list_del corruption. prev->next should be ffff8803e4b678a8, but was 0000000041b58ab3 CPU: 2 PID: 28919 Comm: trinity-c30 Tainted: G B W 4.5.0-think+ #6 ffffffffba5a743c 000000001ded0b05 ffff8803e4b67690 ffffffffba575c0b ffff8803e4b67708 0000000000000000 ffff8803e4b676d8 ffffffffba0b3eb1 ffff88045fbe37c0 0000003bba308c0c ffffed007c96cedd ffff8803ee067be8 Call Trace: [<ffffffffba5a743c>] ? __list_del_entry+0xdc/0x100 [<ffffffffba575c0b>] dump_stack+0x68/0x9d [<ffffffffba0b3eb1>] __warn+0x111/0x130 [<ffffffffba0b3f84>] warn_slowpath_fmt+0xb4/0xf0 [<ffffffffba0b3ed0>] ? __warn+0x130/0x130 [<ffffffffba58c6a4>] ? delay_tsc+0x94/0xc0 [<ffffffffba12eba8>] ? finish_wait+0x68/0xc0 [<ffffffffba5a743c>] __list_del_entry+0xdc/0x100 [<ffffffffba12ebb3>] finish_wait+0x73/0xc0 [<ffffffffba2a6453>] shmem_fault+0x323/0x390 [<ffffffffba2a6130>] ? shmem_file_splice_read+0x720/0x720 [<ffffffffba12f180>] ? prepare_to_wait_event+0x200/0x200 [<ffffffffba1611f5>] ? debug_lockdep_rcu_enabled+0x35/0x40 [<ffffffffba14063f>] ? mark_lock+0xcf/0x800 [<ffffffffba2c3eb8>] __do_fault+0x138/0x2e0 [<ffffffffba2c3d80>] ? wp_page_copy.isra.79+0x850/0x850 [<ffffffffba2c9a5b>] handle_mm_fault+0x42b/0x2400 [<ffffffffba141e38>] ? __lock_acquire+0x8b8/0x1c60 [<ffffffffba14063f>] ? mark_lock+0xcf/0x800 [<ffffffffba1611aa>] ? debug_lockdep_rcu_enabled.part.18+0x1a/0x30 [<ffffffffba035e36>] ? native_sched_clock+0x66/0x160 [<ffffffffba2c9630>] ? copy_page_range+0xec0/0xec0 [<ffffffffba0f7a9e>] ? ___might_sleep.part.86+0x1de/0x2c0 [<ffffffffba2bd8ad>] ? vmacache_find+0xed/0x140 [<ffffffffba0722d2>] __do_page_fault+0x1d2/0x5a0 [<ffffffffba4dd0d0>] ? SyS_shmget+0x100/0x100 [<ffffffffba0726c0>] do_page_fault+0x20/0x70 [<ffffffffbad469d7>] ? native_iret+0x7/0x7 [<ffffffffbad47cdf>] page_fault+0x1f/0x30 [<ffffffffba4dd0d0>] ? SyS_shmget+0x100/0x100 [<ffffffffba58c112>] ? copy_user_enhanced_fast_string+0x2/0x10 [<ffffffffba4dcb7f>] ? shmctl_nolock.constprop.24+0x5ff/0x690 [<ffffffffba4dc847>] ? shmctl_nolock.constprop.24+0x2c7/0x690 [<ffffffffba141580>] ? debug_check_no_locks_freed+0x1b0/0x1b0 [<ffffffffba4dc580>] ? newseg+0x5e0/0x5e0 [<ffffffffba5a7247>] ? debug_smp_processor_id+0x17/0x20 [<ffffffffba0f7849>] ? preempt_count_sub+0xb9/0x130 [<ffffffffba4dd0d0>] ? SyS_shmget+0x100/0x100 [<ffffffffba4dd412>] SyS_shmctl+0x342/0x490 [<ffffffffba003aa4>] do_syscall_64+0xf4/0x240 [<ffffffffbad4605a>] entry_SYSCALL64_slow_path+0x25/0x25 ---[ end trace 638c142c3cb9ddb2 ]---