===================================== WARNING: bad unlock balance detected! syzkaller #0 Not tainted ------------------------------------- dhcpcd/4359 is trying to release lock (rcu_read_lock) at: [] rcu_lock_release+0x18/0x40 include/linux/rcupdate.h:309 but there are no more locks to release! other info that might help us debug this: 1 lock held by dhcpcd/4359: #0: ffff0000d3c26088 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1a4/0x460 mm/mmap_lock.c:310 stack backtrace: CPU: 0 UID: 0 PID: 4359 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 print_unlock_imbalance_bug+0xf4/0xfc kernel/locking/lockdep.c:5298 __lock_release kernel/locking/lockdep.c:-1 [inline] lock_release+0x1dc/0x3b0 kernel/locking/lockdep.c:5889 rcu_lock_release+0x30/0x40 include/linux/rcupdate.h:310 rcu_read_unlock include/linux/rcupdate.h:869 [inline] pte_unmap include/linux/pgtable.h:117 [inline] do_wp_page+0x1f48/0x3fe8 mm/memory.c:4315 handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault mm/memory.c:6549 [inline] handle_mm_fault+0x10d0/0x2450 mm/memory.c:6718 do_page_fault+0x768/0xb64 arch/arm64/mm/fault.c:704 do_mem_abort+0x70/0x190 arch/arm64/mm/fault.c:980 el0_da+0x68/0x23c arch/arm64/kernel/entry-common.c:539 el0t_64_sync_handler+0x10c/0x148 arch/arm64/kernel/entry-common.c:745 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 ------------[ cut here ]------------ WARNING: kernel/rcu/tree_plugin.h:443 at __rcu_read_unlock+0x98/0x104 kernel/rcu/tree_plugin.h:445, CPU#1: dhcpcd/4359 Modules linked in: CPU: 1 UID: 0 PID: 4359 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : __rcu_read_unlock+0x98/0x104 kernel/rcu/tree_plugin.h:445 lr : rcu_read_unlock include/linux/rcupdate.h:871 [inline] lr : pte_unmap include/linux/pgtable.h:117 [inline] lr : do_wp_page+0x1f4c/0x3fe8 mm/memory.c:4315 sp : ffff800095037960 x29: ffff800095037970 x28: ffff700012a06f4c x27: 1ffff00012a06f96 x26: dfff800000000000 x25: ffff800095037cb0 x24: 1fffffbff86f56f8 x23: 1ffff00012a06f8f x22: 0000000000000001 x21: dfff800000000000 x20: 1fffe00019194430 x19: ffff0000c8ca2184 x18: 00000000ffffffff x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000000 x11: 00000000000004dd x10: 0000000000000003 x9 : 0000000000000007 x8 : 0000000000000003 x7 : 0000000000000000 x6 : ffff8000804886d0 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff80008048c3e0 x2 : 0000000100000000 x1 : ffff0000c8ca1d00 x0 : ffff0000c8ca1d00 Call trace: __rcu_read_unlock+0x98/0x104 kernel/rcu/tree_plugin.h:445 (P) rcu_read_unlock include/linux/rcupdate.h:871 [inline] pte_unmap include/linux/pgtable.h:117 [inline] do_wp_page+0x1f4c/0x3fe8 mm/memory.c:4315 handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault mm/memory.c:6549 [inline] handle_mm_fault+0x10d0/0x2450 mm/memory.c:6718 do_page_fault+0x768/0xb64 arch/arm64/mm/fault.c:704 do_mem_abort+0x70/0x190 arch/arm64/mm/fault.c:980 el0_da+0x68/0x23c arch/arm64/kernel/entry-common.c:539 el0t_64_sync_handler+0x10c/0x148 arch/arm64/kernel/entry-common.c:745 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 irq event stamp: 113975 hardirqs last enabled at (113975): [] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:515 [inline] hardirqs last enabled at (113975): [] arm64_exit_to_kernel_mode+0x7c/0x90 arch/arm64/kernel/entry-common.c:62 hardirqs last disabled at (113974): [] __el1_irq arch/arm64/kernel/entry-common.c:493 [inline] hardirqs last disabled at (113974): [] el1_interrupt+0x28/0x60 arch/arm64/kernel/entry-common.c:509 softirqs last enabled at (113934): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32 softirqs last disabled at (113932): [] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19 ---[ end trace 0000000000000000 ]--- BUG: sleeping function called from invalid context at ./include/linux/sched/mm.h:323 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 4359, name: dhcpcd preempt_count: 0, expected: 0 RCU nest depth: -1, expected: 0 INFO: lockdep is turned off. CPU: 1 UID: 0 PID: 4359 Comm: dhcpcd Tainted: G W syzkaller #0 PREEMPT Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 __might_resched+0x350/0x4ac kernel/sched/core.c:9162 __might_sleep+0x84/0xdc kernel/sched/core.c:9091 might_alloc include/linux/sched/mm.h:323 [inline] prepare_alloc_pages+0x178/0x4b0 mm/page_alloc.c:4995 __alloc_frozen_pages_noprof+0x134/0x31c mm/page_alloc.c:5215 alloc_pages_mpol+0x1ec/0x464 mm/mempolicy.c:2490 folio_alloc_mpol_noprof+0x4c/0x248 mm/mempolicy.c:2509 vma_alloc_folio_noprof+0xfc/0x1d8 mm/mempolicy.c:2544 folio_prealloc+0x5c/0x1b0 mm/memory.c:1193 wp_page_copy mm/memory.c:3859 [inline] do_wp_page+0xf9c/0x3fe8 mm/memory.c:4320 handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault mm/memory.c:6549 [inline] handle_mm_fault+0x10d0/0x2450 mm/memory.c:6718 do_page_fault+0x768/0xb64 arch/arm64/mm/fault.c:704 do_mem_abort+0x70/0x190 arch/arm64/mm/fault.c:980 el0_da+0x68/0x23c arch/arm64/kernel/entry-common.c:539 el0t_64_sync_handler+0x10c/0x148 arch/arm64/kernel/entry-common.c:745 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 BUG: sleeping function called from invalid context at kernel/locking/mutex.c:623 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 4359, name: dhcpcd preempt_count: 0, expected: 0 RCU nest depth: -1, expected: 0 INFO: lockdep is turned off. CPU: 0 UID: 0 PID: 4359 Comm: dhcpcd Tainted: G W syzkaller #0 PREEMPT Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 __might_resched+0x350/0x4ac kernel/sched/core.c:9162 __might_sleep+0x84/0xdc kernel/sched/core.c:9091 __mutex_lock_common+0x110/0x20f4 kernel/locking/mutex.c:623 __mutex_lock kernel/locking/mutex.c:820 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:873 __unix_dgram_recvmsg+0x184/0x898 net/unix/af_unix.c:2584 unix_dgram_recvmsg+0xcc/0xe4 net/unix/af_unix.c:2686 unix_seqpacket_recvmsg+0x9c/0xcc net/unix/af_unix.c:2553 sock_recvmsg_nosec net/socket.c:1137 [inline] sock_recvmsg+0xd8/0x134 net/socket.c:1159 sock_read_iter+0x1ec/0x2a8 net/socket.c:1229 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x4ac/0x8e4 fs/read_write.c:574 ksys_read+0x12c/0x224 fs/read_write.c:717 __do_sys_read fs/read_write.c:726 [inline] __se_sys_read fs/read_write.c:724 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:724 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x60/0x25c arch/arm64/kernel/entry-common.c:723 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:742 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594