===================================== WARNING: bad unlock balance detected! syzkaller #0 Not tainted ------------------------------------- rm/5648 is trying to release lock (rcu_read_lock) at: [] rcu_read_unlock+0x2d/0xb0 include/linux/rcupdate.h:867 but there are no more locks to release! other info that might help us debug this: 1 lock held by rm/5648: #0: ffff8880253fbd48 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310 stack backtrace: CPU: 2 UID: 0 PID: 5648 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_read_unlock+0x32/0xb0 include/linux/rcupdate.h:867 pte_unmap include/linux/pgtable.h:117 [inline] wp_page_copy mm/memory.c:3960 [inline] do_wp_page+0x13d7/0x4350 mm/memory.c:4320 handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault+0x1ab6/0x2a00 mm/memory.c:6549 handle_mm_fault+0x36d/0xa20 mm/memory.c:6718 do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f5150da7418 Code: fe ff ff 0f 1f 80 00 00 00 00 48 85 f6 0f 84 af 00 00 00 41 f6 85 56 03 00 00 20 0f 85 a1 00 00 00 49 8b 45 60 48 85 c0 74 04 <48> 01 70 08 49 8b 45 58 48 85 c0 74 04 48 01 70 08 49 8b 45 68 48 RSP: 002b:00007fffe33f1de0 EFLAGS: 00010206 RAX: 00007f5150a8dd50 RBX: 0000000000000030 RCX: 00007f5150a996f0 RDX: 00007f5150a8de80 RSI: 00007f5150a2d000 RDI: 000000006fffffff RBP: 00007fffe33f1f30 R08: 0000000000000006 R09: 00000000effffef5 R10: 0000000070000029 R11: 00007fffe33f2018 R12: 00007fffe33f1c90 R13: 00007f5150a996b0 R14: 00007fffe33f1fd0 R15: 00007f5150a8e018 ------------[ 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#2: rm/5648 WARNING: kernel/rcu/tree_plugin.h:443 at __rcu_read_unlock+0x235/0x5e0 kernel/rcu/tree_plugin.h:430, CPU#2: rm/5648 Modules linked in: CPU: 2 UID: 0 PID: 5648 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 c2 6f da ff e8 1d fc 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 c3 cc cc cc cc e8 94 72 88 RSP: 0000:ffffc900031b7af0 EFLAGS: 00010286 RAX: 00000000ffffffff RBX: ffff888023f1a500 RCX: ffffffff81e7b7ae RDX: 0000000000000000 RSI: ffffffff8def9308 RDI: ffff888023f1a9c4 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000080000000 R11: 0000000000000012 R12: ffff888037cb1468 R13: ffffea0001a97140 R14: 0000000000000000 R15: ffffea0001a97140 FS: 0000000000000000(0000) GS:ffff8880d6579000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5150a8dd58 CR3: 000000002cf27000 CR4: 0000000000352ef0 Call Trace: pte_unmap include/linux/pgtable.h:117 [inline] wp_page_copy mm/memory.c:3960 [inline] do_wp_page+0x13d7/0x4350 mm/memory.c:4320 handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault+0x1ab6/0x2a00 mm/memory.c:6549 handle_mm_fault+0x36d/0xa20 mm/memory.c:6718 do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f5150da7418 Code: fe ff ff 0f 1f 80 00 00 00 00 48 85 f6 0f 84 af 00 00 00 41 f6 85 56 03 00 00 20 0f 85 a1 00 00 00 49 8b 45 60 48 85 c0 74 04 <48> 01 70 08 49 8b 45 58 48 85 c0 74 04 48 01 70 08 49 8b 45 68 48 RSP: 002b:00007fffe33f1de0 EFLAGS: 00010206 RAX: 00007f5150a8dd50 RBX: 0000000000000030 RCX: 00007f5150a996f0 RDX: 00007f5150a8de80 RSI: 00007f5150a2d000 RDI: 000000006fffffff RBP: 00007fffe33f1f30 R08: 0000000000000006 R09: 00000000effffef5 R10: 0000000070000029 R11: 00007fffe33f2018 R12: 00007fffe33f1c90 R13: 00007f5150a996b0 R14: 00007fffe33f1fd0 R15: 00007f5150a8e018