===================================== WARNING: bad unlock balance detected! syzkaller #0 Not tainted ------------------------------------- rm/5696 is trying to release lock (rcu_read_lock) at: [] rcu_lock_release include/linux/rcupdate.h:310 [inline] [] rcu_read_unlock include/linux/rcupdate.h:869 [inline] [] pte_unmap include/linux/pgtable.h:117 [inline] [] zap_pte_range mm/memory.c:1948 [inline] [] zap_pmd_range mm/memory.c:2004 [inline] [] zap_pud_range mm/memory.c:2032 [inline] [] zap_p4d_range mm/memory.c:2053 [inline] [] __zap_vma_range+0x22dc/0x4bf0 mm/memory.c:2093 but there are no more locks to release! other info that might help us debug this: 1 lock held by rm/5696: #0: ffff888025cd7178 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline] #0: ffff888025cd7178 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x124/0xa10 mm/mmap.c:1284 stack backtrace: CPU: 1 UID: 0 PID: 5696 Comm: rm 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: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_unlock_imbalance_bug.part.0+0xfb/0x106 kernel/locking/lockdep.c:5298 print_unlock_imbalance_bug kernel/locking/lockdep.c:5278 [inline] __lock_release kernel/locking/lockdep.c:5537 [inline] lock_release kernel/locking/lockdep.c:5889 [inline] lock_release+0x28d/0x310 kernel/locking/lockdep.c:5875 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] pte_unmap include/linux/pgtable.h:117 [inline] zap_pte_range mm/memory.c:1948 [inline] zap_pmd_range mm/memory.c:2004 [inline] zap_pud_range mm/memory.c:2032 [inline] zap_p4d_range mm/memory.c:2053 [inline] __zap_vma_range+0x22e1/0x4bf0 mm/memory.c:2093 unmap_vmas+0x299/0x5f0 mm/memory.c:2162 exit_mmap+0x1ef/0xa10 mm/mmap.c:1300 __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: 0033:0x7fa6bc8586c5 Code: Unable to access opcode bytes at 0x7fa6bc85869b. RSP: 002b:00007ffcce58f088 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fa6bc959fe8 RCX: 00007fa6bc8586c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000 RBP: 0000000000000001 R08: 00007ffcce58f018 R09: 0000000000000000 R10: 00007ffcce58eeb0 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa6bc958680 R15: 00007fa6bc95a000 ------------[ cut here ]------------ rrln < 0 || rrln > RCU_NEST_PMAX WARNING: kernel/rcu/tree_plugin.h:443 at __rcu_read_unlock kernel/rcu/tree_plugin.h:443 [inline], CPU#0: rm/5696 WARNING: kernel/rcu/tree_plugin.h:443 at __rcu_read_unlock+0x235/0x5e0 kernel/rcu/tree_plugin.h:430, CPU#0: rm/5696 Modules linked in: CPU: 0 UID: 0 PID: 5696 Comm: rm 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 RIP: 0010:__rcu_read_unlock kernel/rcu/tree_plugin.h:443 [inline] RIP: 0010:__rcu_read_unlock+0x235/0x5e0 kernel/rcu/tree_plugin.h:430 Code: 74 11 c7 45 58 01 00 00 00 bf 09 00 00 00 e8 92 a3 da ff e8 9d e2 22 00 9c 58 f6 c4 02 0f 85 dd 02 00 00 fb e9 57 fe ff ff 90 <0f> 0b 90 5b 5d 41 5c 41 5d 41 5e 41 5f e9 d9 e0 9c 09 e8 44 64 87 RSP: 0018:ffffc90003d7f778 EFLAGS: 00010286 RAX: 00000000ffffffff RBX: ffff888029068000 RCX: ffffffff81e7203e RDX: 0000000000000000 RSI: ffffffff8def4169 RDI: ffff8880290684c4 RBP: 0000000000000004 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000080000000 R11: 0000000000000001 R12: ffff888025cd76f8 R13: fffffbfff21afcbc R14: 0000000000000000 R15: 00007fa6bc76c000 FS: 0000000000000000(0000) GS:ffff888097180000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdc3700a6b0 CR3: 000000000e596000 CR4: 0000000000352ef0 Call Trace: rcu_read_unlock include/linux/rcupdate.h:871 [inline] pte_unmap include/linux/pgtable.h:117 [inline] zap_pte_range mm/memory.c:1948 [inline] zap_pmd_range mm/memory.c:2004 [inline] zap_pud_range mm/memory.c:2032 [inline] zap_p4d_range mm/memory.c:2053 [inline] __zap_vma_range+0x22e6/0x4bf0 mm/memory.c:2093 unmap_vmas+0x299/0x5f0 mm/memory.c:2162 exit_mmap+0x1ef/0xa10 mm/mmap.c:1300 __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: 0033:0x7fa6bc8586c5 Code: Unable to access opcode bytes at 0x7fa6bc85869b. RSP: 002b:00007ffcce58f088 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fa6bc959fe8 RCX: 00007fa6bc8586c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000 RBP: 0000000000000001 R08: 00007ffcce58f018 R09: 0000000000000000 R10: 00007ffcce58eeb0 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa6bc958680 R15: 00007fa6bc95a000