On 4.9.13 with KASAN enabled [1], we see a number of stack unwinding errors reported [2,3].
This seems to occur at half of boots. Let me know for further debug info/patch testing and thanks, Daniel [1] https://quora.org/config [2] https://quora.org/dmesg.txt -- [3] BUG: KASAN: stack-out-of-bounds in unwind_get_return_address+0x11d/0x130 at addr ffff881034eafa08 Read of size 8 by task systemd/1 page:ffffea0040d3abc0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x2fffff80000000() page dumped because: kasan: bad access detected CPU: 20 PID: 1 Comm: systemd Not tainted 4.9.13-debug+ #3 Hardware name: Supermicro Super Server/X10DRL-i, BIOS 2.0a 08/25/2016 ffff881c2f607a60 ffffffffb0cdb541 ffff881c2f607af8 ffff881034eafa08 ffff881c2f607ae8 ffffffffb064dd17 ffff881034ea4f70 ffffffff00000024 0000000000000000 0000000000000286 ffff881034ea4fe2 0000000000000000 Call Trace: <IRQ> [<ffffffffb0cdb541>] dump_stack+0x85/0xc4 [<ffffffffb064dd17>] kasan_report_error+0x4d7/0x500 [<ffffffffb064def1>] __asan_report_load8_noabort+0x61/0x70 [<ffffffffb012b42d>] ? unwind_get_return_address+0x11d/0x130 [<ffffffffb012b42d>] unwind_get_return_address+0x11d/0x130 [<ffffffffb012b627>] ? unwind_next_frame+0x97/0xf0 [<ffffffffb00bc7a2>] __save_stack_trace+0x92/0x100 [<ffffffffb06b7976>] ? file_free_rcu+0x46/0x60 [<ffffffffb00bc82b>] save_stack_trace+0x1b/0x20 [<ffffffffb064cb26>] save_stack+0x46/0xd0 [<ffffffffb00bc82b>] ? save_stack_trace+0x1b/0x20 [<ffffffffb064cb26>] ? save_stack+0x46/0xd0 [<ffffffffb064d371>] ? kasan_slab_free+0x71/0xb0 [<ffffffffb0648714>] ? kmem_cache_free+0xc4/0x350 [<ffffffffb06b7976>] ? file_free_rcu+0x46/0x60 [<ffffffffb02e5bf2>] ? rcu_process_callbacks+0x9d2/0x1220 [<ffffffffb1bdb886>] ? __do_softirq+0x286/0x87d [<ffffffffb018fd00>] ? irq_exit+0x160/0x190 [<ffffffffb1bdb130>] ? smp_apic_timer_interrupt+0x80/0xa0 [<ffffffffb1bda1bc>] ? apic_timer_interrupt+0x8c/0xa0 [<ffffffffb028da60>] ? debug_check_no_locks_freed+0x290/0x290 [<ffffffffb0d4a788>] ? debug_object_deactivate+0xf8/0x320 [<ffffffffb1bd7bef>] ? _raw_spin_unlock_irqrestore+0x5f/0x80 [<ffffffffb028d07e>] ? trace_hardirqs_on_caller+0x19e/0x580 [<ffffffffb1bd7bda>] ? _raw_spin_unlock_irqrestore+0x4a/0x80 [<ffffffffb028ce88>] ? mark_held_locks+0xc8/0x120 [<ffffffffb06486ff>] ? kmem_cache_free+0xaf/0x350 [<ffffffffb06b7976>] ? file_free_rcu+0x46/0x60 [<ffffffffb064d371>] kasan_slab_free+0x71/0xb0 [<ffffffffb0648714>] kmem_cache_free+0xc4/0x350 [<ffffffffb06b7976>] file_free_rcu+0x46/0x60 [<ffffffffb02e5bf2>] rcu_process_callbacks+0x9d2/0x1220 [<ffffffffb02e5b9d>] ? rcu_process_callbacks+0x97d/0x1220 [<ffffffffb06b7930>] ? get_max_files+0x20/0x20 [<ffffffffb1bdb886>] __do_softirq+0x286/0x87d [<ffffffffb018fd00>] irq_exit+0x160/0x190 [<ffffffffb1bdb130>] smp_apic_timer_interrupt+0x80/0xa0 [<ffffffffb1bda1bc>] apic_timer_interrupt+0x8c/0xa0 <EOI> [<ffffffffb064cb26>] ? save_stack+0x46/0xd0 [<ffffffffb028da60>] ? debug_check_no_locks_freed+0x290/0x290 [<ffffffffb028ce88>] ? mark_held_locks+0xc8/0x120 [<ffffffffb0162da8>] ? efi_call+0x58/0x90 [<ffffffffb16ca79c>] ? virt_efi_get_variable+0x9c/0x150 [<ffffffffb16beb64>] ? efivar_entry_size+0xa4/0x110 [<ffffffffb0a7303f>] ? efivarfs_callback+0x30f/0x4e7 [<ffffffffb0a72d30>] ? efivarfs_evict_inode+0x10/0x10 [<ffffffffb028ce88>] mark_held_locks+0xc8/0x120 [<ffffffffb1bd7bef>] ? _raw_spin_unlock_irqrestore+0x5f/0x80 [<ffffffffb1bd7bda>] ? _raw_spin_unlock_irqrestore+0x4a/0x80 [<ffffffffb16c06d2>] ? efivar_init+0x512/0x750 [<ffffffffb0a72d30>] ? efivarfs_evict_inode+0x10/0x10 [<ffffffffb16c01c0>] ? efivar_entry_iter+0x140/0x140 [<ffffffffb02d9847>] ? debug_lockdep_rcu_enabled+0x77/0x90 [<ffffffffb06f7d0f>] ? d_instantiate+0x6f/0x80 [<ffffffffb1bd7ad1>] ? _raw_spin_unlock+0x31/0x50 [<ffffffffb1bd7ad1>] ? _raw_spin_unlock+0x31/0x50 [<ffffffffb06f7d0f>] ? d_instantiate+0x6f/0x80 [<ffffffffb0a72780>] ? efivarfs_mount+0x20/0x20 [<ffffffffb0a7296a>] ? efivarfs_fill_super+0x1ea/0x290 [<ffffffffb0a72780>] ? efivarfs_mount+0x20/0x20 [<ffffffffb06bd14c>] ? mount_single+0xcc/0x130 [<ffffffffb0a72778>] ? efivarfs_mount+0x18/0x20 [<ffffffffb06bd3a1>] ? mount_fs+0x81/0x2c0 [<ffffffffb0717081>] ? alloc_vfsmnt+0x451/0x720 [<ffffffffb071859b>] ? vfs_kern_mount+0x6b/0x370 [<ffffffffb0720815>] ? do_mount+0x355/0x2af0 [<ffffffffb02d9847>] ? debug_lockdep_rcu_enabled+0x77/0x90 [<ffffffffb07204c0>] ? copy_mount_string+0x20/0x20 [<ffffffffb05bb096>] ? __might_fault+0xf6/0x1b0 [<ffffffffb06a77e4>] ? __check_object_size+0x1b4/0x3fe [<ffffffffb058ab5b>] ? memdup_user+0x6b/0xa0 [<ffffffffb0723c95>] ? SyS_mount+0x95/0xe0 [<ffffffffb1bd8405>] ? entry_SYSCALL_64_fastpath+0x23/0xc6 Memory state around the buggy address: ffff881034eaf900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff881034eaf980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 >ffff881034eafa00: f1 f1 00 f4 f4 f4 f2 f2 f2 f2 00 00 f4 f4 f3 f3 ^ ffff881034eafa80: f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff881034eafb00: 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f4 Disabling lock debugging due to kernel taint -- Daniel J Blueman