BUG: sleeping function called from invalid context at mm/mmu_gather.c:142
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5704, name: cmp
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
2 locks held by cmp/5704:
 #0: ffff88803d5be538 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline]
 #0: ffff88803d5be538 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x22c/0xa10 mm/mmap.c:1308
 #1: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire.constprop.0+0x7/0x30 include/linux/rcupdate.h:300
CPU: 1 UID: 0 PID: 5704 Comm: cmp Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 __might_resched.cold+0x1ec/0x232 kernel/sched/core.c:9162
 __tlb_batch_free_encoded_pages+0x11e/0x280 mm/mmu_gather.c:142
 tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:417 [inline]
 tlb_flush_mmu mm/mmu_gather.c:424 [inline]
 tlb_finish_mmu+0x1b0/0x810 mm/mmu_gather.c:549
 exit_mmap+0x454/0xa10 mm/mmap.c:1313
 __mmput+0x12a/0x410 kernel/fork.c:1178
 mmput+0x67/0x80 kernel/fork.c:1201
 exit_mm kernel/exit.c:581 [inline]
 do_exit+0x833/0x2a60 kernel/exit.c:963
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1117
 __do_sys_exit_group kernel/exit.c:1128 [inline]
 __se_sys_exit_group kernel/exit.c:1126 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1126
 x64_sys_call+0x102c/0x1530 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd8f407d6c5
Code: Unable to access opcode bytes at 0x7fd8f407d69b.
RSP: 002b:00007ffe687a46e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fd8f417efe8 RCX: 00007fd8f407d6c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000001 R08: 00007ffe687a4678 R09: 0000000000000000
R10: 00007ffe687a4510 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd8f417d680 R15: 00007fd8f417f000
 </TASK>

====================================
WARNING: cmp/5704 still has locks held!
syzkaller #0 Tainted: G        W          
------------------------------------
1 lock held by cmp/5704:
 #0: ffffffff8e7e54e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire.constprop.0+0x7/0x30 include/linux/rcupdate.h:300

stack backtrace:
CPU: 1 UID: 0 PID: 5704 Comm: cmp Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_held_locks_bug kernel/locking/lockdep.c:6752 [inline]
 debug_check_no_locks_held+0x90/0xa0 kernel/locking/lockdep.c:6760
 do_exit+0x13ea/0x2a60 kernel/exit.c:997
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1117
 __do_sys_exit_group kernel/exit.c:1128 [inline]
 __se_sys_exit_group kernel/exit.c:1126 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1126
 x64_sys_call+0x102c/0x1530 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd8f407d6c5
Code: Unable to access opcode bytes at 0x7fd8f407d69b.
RSP: 002b:00007ffe687a46e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fd8f417efe8 RCX: 00007fd8f407d6c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000001 R08: 00007ffe687a4678 R09: 0000000000000000
R10: 00007ffe687a4510 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd8f417d680 R15: 00007fd8f417f000
 </TASK>