===================================== WARNING: bad unlock balance detected! syzkaller #0 Not tainted ------------------------------------- dhcpcd-run-hook/5684 is trying to release lock (rcu_read_lock) at: [] rcu_lock_release include/linux/rcupdate.h:310 [inline] [] rcu_read_unlock+0x17/0x60 include/linux/rcupdate.h:869 but there are no more locks to release! other info that might help us debug this: 2 locks held by dhcpcd-run-hook/5684: #0: ffff888036590338 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline] #0: ffff888036590338 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x124/0xa10 mm/mmap.c:1284 #1: ffff88803e19f558 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline] #1: ffff88803e19f558 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x10f/0x320 mm/pgtable-generic.c:404 stack backtrace: CPU: 2 UID: 0 PID: 5684 Comm: dhcpcd-run-hook 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+0x1c/0x60 include/linux/rcupdate.h:869 __folio_mod_stat mm/rmap.c:1336 [inline] __folio_remove_rmap mm/rmap.c:1873 [inline] folio_remove_rmap_ptes+0x79a/0xdd0 mm/rmap.c:1900 zap_present_folio_ptes mm/memory.c:1656 [inline] zap_present_ptes mm/memory.c:1714 [inline] do_zap_pte_range mm/memory.c:1816 [inline] zap_pte_range mm/memory.c:1918 [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+0x1f72/0x4bf0 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: 0033:0x7f86edb946c5 Code: Unable to access opcode bytes at 0x7f86edb9469b. RSP: 002b:00007ffe0360d588 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000556aa8bde2c0 RCX: 00007f86edb946c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000 RBP: 00007ffe0360d8b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe0360d8b0 R13: 00007ffe0360d8c0 R14: 00007f86edda4000 R15: 0000556a73d27d98 ------------[ 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: dhcpcd-run-hook/5684 WARNING: kernel/rcu/tree_plugin.h:443 at __rcu_read_unlock+0x235/0x5e0 kernel/rcu/tree_plugin.h:430, CPU#2: dhcpcd-run-hook/5684 Modules linked in: CPU: 2 UID: 0 PID: 5684 Comm: dhcpcd-run-hook 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 9d ff 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 54 76 88 RSP: 0018:ffffc90003bdf718 EFLAGS: 00010286 RAX: 00000000ffffffff RBX: ffff8880285b2500 RCX: ffffffff81e7b7ae RDX: 0000000000000000 RSI: ffffffff8def8e2a RDI: ffff8880285b29c4 RBP: ffffea0000f25740 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000080000001 R11: 0000000000000001 R12: 0000000000000001 R13: ffff88803e85cc80 R14: 0000000000000000 R15: ffffea0000f25770 FS: 0000000000000000(0000) GS:ffff8880d6579000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556aa8be3b11 CR3: 000000002c8aa000 CR4: 0000000000352ef0 Call Trace: __folio_mod_stat mm/rmap.c:1336 [inline] __folio_remove_rmap mm/rmap.c:1873 [inline] folio_remove_rmap_ptes+0x79a/0xdd0 mm/rmap.c:1900 zap_present_folio_ptes mm/memory.c:1656 [inline] zap_present_ptes mm/memory.c:1714 [inline] do_zap_pte_range mm/memory.c:1816 [inline] zap_pte_range mm/memory.c:1918 [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+0x1f72/0x4bf0 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: 0033:0x7f86edb946c5 Code: Unable to access opcode bytes at 0x7f86edb9469b. RSP: 002b:00007ffe0360d588 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000556aa8bde2c0 RCX: 00007f86edb946c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000 RBP: 00007ffe0360d8b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe0360d8b0 R13: 00007ffe0360d8c0 R14: 00007f86edda4000 R15: 0000556a73d27d98