BUG: sleeping function called from invalid context at mm/vmalloc.c:3409
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 5378, name: klogd
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
no locks held by klogd/5378.
Preemption disabled at:
[<ffffffff8b91cf20>] __schedule_loop kernel/sched/core.c:7042 [inline]
[<ffffffff8b91cf20>] schedule+0xe0/0x3a0 kernel/sched/core.c:7058
CPU: 3 UID: 0 PID: 5378 Comm: klogd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120
 __might_resched+0x3c0/0x5e0 kernel/sched/core.c:8957
 vfree+0x75/0xb50 mm/vmalloc.c:3409
 futex_hash_free+0x98/0xc0 kernel/futex/core.c:1742
 __mmdrop+0x33f/0x580 kernel/fork.c:692
 mmdrop include/linux/sched/mm.h:55 [inline]
 mmdrop_sched include/linux/sched/mm.h:83 [inline]
 mmdrop_lazy_tlb_sched include/linux/sched/mm.h:110 [inline]
 finish_task_switch.isra.0+0x7a4/0xc10 kernel/sched/core.c:5250
 context_switch kernel/sched/core.c:5360 [inline]
 __schedule+0x1198/0x5de0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7058
 syslog_print+0x216/0x620 kernel/printk/printk.c:1633
 do_syslog+0x3dc/0x6c0 kernel/printk/printk.c:1785
 __do_sys_syslog kernel/printk/printk.c:1877 [inline]
 __se_sys_syslog kernel/printk/printk.c:1875 [inline]
 __x64_sys_syslog+0x74/0xb0 kernel/printk/printk.c:1875
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f477cacba37
Code: 73 01 c3 48 8b 0d c1 f3 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 67 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 f3 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffe65d79cf8 EFLAGS: 00000206 ORIG_RAX: 0000000000000067
RAX: ffffffffffffffda RBX: 00007f477cc6b490 RCX: 00007f477cacba37
RDX: 00000000000003ff RSI: 00007f477cc6b490 RDI: 0000000000000002
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000206 R12: 00007f477cc6b490
R13: 00007f477cc48dfe R14: 00007f477cc6b4e3 R15: 00007f477cc6b4e3
 </TASK>