------------[ cut here ]------------ ====================================================== WARNING: possible circular locking dependency detected 5.15.174-syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:12/4392 is trying to acquire lock: ffffffff8c9fc578 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:138 but task is already holding lock: ffff8880b8f28098 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:946 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&base->lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 lock_timer_base+0x120/0x260 kernel/time/timer.c:946 __mod_timer+0x1d6/0xeb0 kernel/time/timer.c:1019 queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1715 psi_enqueue kernel/sched/stats.h:104 [inline] enqueue_task+0x2fe/0x3a0 kernel/sched/core.c:1970 activate_task kernel/sched/core.c:2002 [inline] wake_up_new_task+0x515/0xb60 kernel/sched/core.c:4519 kernel_clone+0x44e/0x960 kernel/fork.c:2627 kernel_thread+0x168/0x1e0 kernel/fork.c:2655 rest_init+0x21/0x330 init/main.c:706 start_kernel+0x48c/0x540 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:368 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 raw_spin_rq_lock kernel/sched/sched.h:1326 [inline] rq_lock kernel/sched/sched.h:1621 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11488 sched_cgroup_fork+0x2d3/0x330 kernel/sched/core.c:4463 copy_process+0x224a/0x3ef0 kernel/fork.c:2319 kernel_clone+0x210/0x960 kernel/fork.c:2603 kernel_thread+0x168/0x1e0 kernel/fork.c:2655 rest_init+0x21/0x330 init/main.c:706 start_kernel+0x48c/0x540 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb -> #1 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4027 up+0x6e/0x90 kernel/locking/semaphore.c:190 __up_console_sem+0x11a/0x1e0 kernel/printk/printk.c:256 console_unlock+0x1145/0x12b0 kernel/printk/printk.c:2760 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 -> #0 ((console_sem).lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:138 __down_trylock_console_sem+0x105/0x250 kernel/printk/printk.c:239 console_trylock kernel/printk/printk.c:2575 [inline] console_trylock_spinning+0x8a/0x3f0 kernel/printk/printk.c:1867 vprintk_emit+0xa6/0x150 kernel/printk/printk.c:2273 _printk+0xd1/0x120 kernel/printk/printk.c:2299 report_bug+0x1e5/0x2e0 lib/bug.c:195 handle_bug+0x3d/0x70 arch/x86/kernel/traps.c:239 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:259 asm_exc_invalid_op+0x16/0x20 arch/x86/include/asm/idtentry.h:604 copy_from_user_nofault+0x15c/0x1c0 bpf_probe_read_user_common kernel/trace/bpf_trace.c:157 [inline] ____bpf_probe_read_user kernel/trace/bpf_trace.c:166 [inline] bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:163 bpf_prog_02073d59a3c0f06f+0x3d/0x744 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:621 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run3+0x2ce/0x380 kernel/trace/bpf_trace.c:1916 __traceiter_timer_start+0x79/0xd0 include/trace/events/timer.h:52 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x3ae/0x540 kernel/time/timer.c:586 internal_add_timer kernel/time/timer.c:611 [inline] __mod_timer+0xa60/0xeb0 kernel/time/timer.c:1062 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558 __do_softirq kernel/softirq.c:592 [inline] invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 lock_release+0x62d/0x9a0 kernel/locking/lockdep.c:5647 rcu_read_unlock include/linux/rcupdate.h:772 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline] batadv_nc_worker+0x239/0x5b0 net/batman-adv/network-coding.c:723 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 other info that might help us debug this: Chain exists of: (console_sem).lock --> &rq->__lock --> &base->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&base->lock); lock(&rq->__lock); lock(&base->lock); lock((console_sem).lock); *** DEADLOCK *** 5 locks held by kworker/u4:12/4392: #0: ffff88802bff4938 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000302fd20 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffc90000dd0be0 ((&app->join_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:45 [inline] #2: ffffc90000dd0be0 ((&app->join_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x560 kernel/time/timer.c:1441 #3: ffff8880b8f28098 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:946 #4: ffffffff8cb1fd20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 stack backtrace: CPU: 1 PID: 4392 Comm: kworker/u4:12 Not tainted 5.15.174-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 Workqueue: bat_events batadv_nc_worker Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:138 __down_trylock_console_sem+0x105/0x250 kernel/printk/printk.c:239 console_trylock kernel/printk/printk.c:2575 [inline] console_trylock_spinning+0x8a/0x3f0 kernel/printk/printk.c:1867 vprintk_emit+0xa6/0x150 kernel/printk/printk.c:2273 _printk+0xd1/0x120 kernel/printk/printk.c:2299 report_bug+0x1e5/0x2e0 lib/bug.c:195 handle_bug+0x3d/0x70 arch/x86/kernel/traps.c:239 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:259 asm_exc_invalid_op+0x16/0x20 arch/x86/include/asm/idtentry.h:604 RIP: 0010:copy_from_user_nofault+0x15c/0x1c0 mm/maccess.c:226 Code: db 48 c7 c0 f2 ff ff ff 48 0f 44 c5 eb 0c e8 7b c5 d5 ff 48 c7 c0 f2 ff ff ff 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 64 c5 d5 ff <0f> 0b e9 1e ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c ef fe ff RSP: 0000:ffffc90000dd0860 EFLAGS: 00010046 RAX: ffffffff81aabf7c RBX: 0000000000000000 RCX: ffff8880277d1dc0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff81aabe8d R09: ffffffff8f89e048 R10: ffffffff8f89e058 R11: ffffffff8f89e050 R12: 0000000000000000 R13: 0000000000000008 R14: 0000000000000000 R15: ffffc90000dd08c8 bpf_probe_read_user_common kernel/trace/bpf_trace.c:157 [inline] ____bpf_probe_read_user kernel/trace/bpf_trace.c:166 [inline] bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:163 bpf_prog_02073d59a3c0f06f+0x3d/0x744 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:621 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run3+0x2ce/0x380 kernel/trace/bpf_trace.c:1916 __traceiter_timer_start+0x79/0xd0 include/trace/events/timer.h:52 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x3ae/0x540 kernel/time/timer.c:586 internal_add_timer kernel/time/timer.c:611 [inline] __mod_timer+0xa60/0xeb0 kernel/time/timer.c:1062 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558 __do_softirq kernel/softirq.c:592 [inline] invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_release+0x62d/0x9a0 kernel/locking/lockdep.c:5647 Code: 3c 3b 00 74 08 4c 89 f7 e8 b0 66 67 00 f6 84 24 91 00 00 00 02 75 6f 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0000:ffffc9000302fac0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000605f6a RCX: ffffc9000302fb03 RDX: 0000000000000002 RSI: ffffffff8aab3e20 RDI: ffffffff8af9f000 RBP: ffffc9000302fbe8 R08: dffffc0000000000 R09: fffffbfff1c14c06 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000605f64 R13: 0000000000000246 R14: ffffc9000302fb50 R15: dffffc0000000000 rcu_read_unlock include/linux/rcupdate.h:772 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline] batadv_nc_worker+0x239/0x5b0 net/batman-adv/network-coding.c:723 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 WARNING: CPU: 1 PID: 4392 at mm/maccess.c:226 copy_from_user_nofault+0x15c/0x1c0 Modules linked in: CPU: 1 PID: 4392 Comm: kworker/u4:12 Not tainted 5.15.174-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 Workqueue: bat_events batadv_nc_worker RIP: 0010:copy_from_user_nofault+0x15c/0x1c0 mm/maccess.c:226 Code: db 48 c7 c0 f2 ff ff ff 48 0f 44 c5 eb 0c e8 7b c5 d5 ff 48 c7 c0 f2 ff ff ff 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 64 c5 d5 ff <0f> 0b e9 1e ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c ef fe ff RSP: 0000:ffffc90000dd0860 EFLAGS: 00010046 RAX: ffffffff81aabf7c RBX: 0000000000000000 RCX: ffff8880277d1dc0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff81aabe8d R09: ffffffff8f89e048 R10: ffffffff8f89e058 R11: ffffffff8f89e050 R12: 0000000000000000 R13: 0000000000000008 R14: 0000000000000000 R15: ffffc90000dd08c8 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000060f75000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bpf_probe_read_user_common kernel/trace/bpf_trace.c:157 [inline] ____bpf_probe_read_user kernel/trace/bpf_trace.c:166 [inline] bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:163 bpf_prog_02073d59a3c0f06f+0x3d/0x744 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:621 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run3+0x2ce/0x380 kernel/trace/bpf_trace.c:1916 __traceiter_timer_start+0x79/0xd0 include/trace/events/timer.h:52 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x3ae/0x540 kernel/time/timer.c:586 internal_add_timer kernel/time/timer.c:611 [inline] __mod_timer+0xa60/0xeb0 kernel/time/timer.c:1062 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558 __do_softirq kernel/softirq.c:592 [inline] invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_release+0x62d/0x9a0 kernel/locking/lockdep.c:5647 Code: 3c 3b 00 74 08 4c 89 f7 e8 b0 66 67 00 f6 84 24 91 00 00 00 02 75 6f 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0000:ffffc9000302fac0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000605f6a RCX: ffffc9000302fb03 RDX: 0000000000000002 RSI: ffffffff8aab3e20 RDI: ffffffff8af9f000 RBP: ffffc9000302fbe8 R08: dffffc0000000000 R09: fffffbfff1c14c06 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000605f64 R13: 0000000000000246 R14: ffffc9000302fb50 R15: dffffc0000000000 rcu_read_unlock include/linux/rcupdate.h:772 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline] batadv_nc_worker+0x239/0x5b0 net/batman-adv/network-coding.c:723 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 ---------------- Code disassembly (best guess): 0: 3c 3b cmp $0x3b,%al 2: 00 74 08 4c add %dh,0x4c(%rax,%rcx,1) 6: 89 f7 mov %esi,%edi 8: e8 b0 66 67 00 call 0x6766bd d: f6 84 24 91 00 00 00 testb $0x2,0x91(%rsp) 14: 02 15: 75 6f jne 0x86 17: 41 f7 c5 00 02 00 00 test $0x200,%r13d 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 60 0e 36 movq $0x45e0360e,0x60(%rsp) 28: e0 45 * 2a: 4b c7 04 27 00 00 00 movq $0x0,(%r15,%r12,1) <-- trapping instruction 31: 00 32: 4b c7 44 27 08 00 00 movq $0x0,0x8(%r15,%r12,1) 39: 00 00 3b: 65 gs 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 04 25 add $0x25,%al