====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc6-syzkaller-01236-gcf6d9fe09185 #0 Not tainted ------------------------------------------------------ syz-executor933/5842 is trying to acquire lock: ffff8880b8629430 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:3312 [inline] ffff8880b8629430 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3725 [inline] ffff8880b8629430 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x18a/0x790 kernel/rcu/tree.c:3811 but task is already holding lock: ffff8880b862a718 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x112/0x240 kernel/time/timer.c:1051 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&base->lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 lock_timer_base+0x112/0x240 kernel/time/timer.c:1051 __mod_timer+0x1ca/0xeb0 kernel/time/timer.c:1132 queue_delayed_work_on+0x1ca/0x390 kernel/workqueue.c:2552 kvfree_call_rcu+0x47f/0x790 kernel/rcu/tree.c:3839 pwq_release_workfn+0x664/0x800 kernel/workqueue.c:5078 kthread_worker_fn+0x500/0xb70 kernel/kthread.c:844 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (krc.lock){..-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:3312 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3725 [inline] kvfree_call_rcu+0x18a/0x790 kernel/rcu/tree.c:3811 trie_delete_elem+0x546/0x6a0 kernel/bpf/lpm_trie.c:540 bpf_prog_2c29ac5cdc6b1842+0x43/0x47 bpf_dispatcher_nop_func include/linux/bpf.h:1265 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2316 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2357 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x3ce/0x570 kernel/time/timer.c:663 internal_add_timer kernel/time/timer.c:688 [inline] __mod_timer+0xa0e/0xeb0 kernel/time/timer.c:1183 dsp_cmx_send+0x21bf/0x2240 drivers/isdn/mISDN/dsp_cmx.c:1839 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1794 expire_timers kernel/time/timer.c:1845 [inline] __run_timers kernel/time/timer.c:2419 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2430 run_timer_base kernel/time/timer.c:2439 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2449 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 preempt_count arch/x86/include/asm/preempt.h:26 [inline] check_kcov_mode kernel/kcov.c:183 [inline] write_comp_data kernel/kcov.c:246 [inline] __sanitizer_cov_trace_const_cmp8+0x18/0x90 kernel/kcov.c:321 pmd_none arch/x86/include/asm/pgtable.h:1069 [inline] filemap_map_pmd mm/filemap.c:3474 [inline] filemap_map_pages+0x48f/0x20d0 mm/filemap.c:3649 do_fault_around mm/memory.c:5255 [inline] do_read_fault mm/memory.c:5288 [inline] do_fault mm/memory.c:5431 [inline] do_pte_missing mm/memory.c:3965 [inline] handle_pte_fault+0x2b98/0x6820 mm/memory.c:5766 __handle_mm_fault mm/memory.c:5909 [inline] handle_mm_fault+0x1106/0x1bb0 mm/memory.c:6077 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x459/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&base->lock); lock(krc.lock); lock(&base->lock); lock(krc.lock); *** DEADLOCK *** 7 locks held by syz-executor933/5842: #0: ffff888074d99808 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:704 [inline] #0: ffff888074d99808 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x34b/0x790 mm/memory.c:6243 #1: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #1: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: do_fault_around mm/memory.c:5254 [inline] #1: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: do_read_fault mm/memory.c:5288 [inline] #1: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: do_fault mm/memory.c:5431 [inline] #1: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: do_pte_missing mm/memory.c:3965 [inline] #1: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: handle_pte_fault+0x2188/0x6820 mm/memory.c:5766 #2: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #2: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: filemap_map_pages+0x243/0x20d0 mm/filemap.c:3644 #3: ffffc90000007c00 ((&dsp_spl_tl)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x650 kernel/time/timer.c:1791 #4: ffffffff8fa04118 (dsp_lock){..-.}-{2:2}, at: dsp_cmx_send+0x26/0x2240 drivers/isdn/mISDN/dsp_cmx.c:1632 #5: ffff8880b862a718 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x112/0x240 kernel/time/timer.c:1051 #6: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #6: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #6: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2315 [inline] #6: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2357 stack backtrace: CPU: 0 UID: 0 PID: 5842 Comm: syz-executor933 Not tainted 6.12.0-rc6-syzkaller-01236-gcf6d9fe09185 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:3312 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3725 [inline] kvfree_call_rcu+0x18a/0x790 kernel/rcu/tree.c:3811 trie_delete_elem+0x546/0x6a0 kernel/bpf/lpm_trie.c:540 bpf_prog_2c29ac5cdc6b1842+0x43/0x47 bpf_dispatcher_nop_func include/linux/bpf.h:1265 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2316 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2357 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x3ce/0x570 kernel/time/timer.c:663 internal_add_timer kernel/time/timer.c:688 [inline] __mod_timer+0xa0e/0xeb0 kernel/time/timer.c:1183 dsp_cmx_send+0x21bf/0x2240 drivers/isdn/mISDN/dsp_cmx.c:1839 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1794 expire_timers kernel/time/timer.c:1845 [inline] __run_timers kernel/time/timer.c:2419 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2430 run_timer_base kernel/time/timer.c:2439 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2449 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data kernel/kcov.c:246 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x18/0x90 kernel/kcov.c:321 Code: 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 4c 8b 04 24 65 48 8b 0c 25 c0 d5 03 00 65 8b 05 70 f6 6e 7e <25> 00 01 ff 00 74 10 3d 00 01 00 00 75 57 83 b9 1c 16 00 00 00 74 RSP: 0000:ffffc90003c97758 EFLAGS: 00000246 RAX: 0000000080000000 RBX: 0000000000000000 RCX: ffff88802c8e9e00 RDX: 0000000000000000 RSI: 0000000076671007 RDI: 0000000000000000 RBP: ffffc90003c97970 R08: ffffffff81cdd89f R09: 1ffffd4000391858 R10: dffffc0000000000 R11: fffff94000391859 R12: ffffc90003c97e30 R13: 0000000076671067 R14: ffff88807c0e1300 R15: 1ffff92000792fc6 pmd_none arch/x86/include/asm/pgtable.h:1069 [inline] filemap_map_pmd mm/filemap.c:3474 [inline] filemap_map_pages+0x48f/0x20d0 mm/filemap.c:3649 do_fault_around mm/memory.c:5255 [inline] do_read_fault mm/memory.c:5288 [inline] do_fault mm/memory.c:5431 [inline] do_pte_missing mm/memory.c:3965 [inline] handle_pte_fault+0x2b98/0x6820 mm/memory.c:5766 __handle_mm_fault mm/memory.c:5909 [inline] handle_mm_fault+0x1106/0x1bb0 mm/memory.c:6077 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x459/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f5cfc7473b8 Code: Unable to access opcode bytes at 0x7f5cfc74738e. RSP: 002b:00007ffe82e9a508 EFLAGS: 00010202 RAX: 00007f5cfc777af8 RBX: 0000000000000000 RCX: 0000000000000004 RDX: 00007f5cfc778d20 RSI: 0000000000000000 RDI: 00007f5cfc777af8 RBP: 00007f5cfc776138 R08: 0000000000000006 R09: 0000000000000006 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5cfc778d08 R13: 0000000000000000 R14: 00007f5cfc778d20 R15: 00007f5cfc6ce3a0 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 90 nop 3: 90 nop 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 90 nop 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: f3 0f 1e fa endbr64 16: 4c 8b 04 24 mov (%rsp),%r8 1a: 65 48 8b 0c 25 c0 d5 mov %gs:0x3d5c0,%rcx 21: 03 00 23: 65 8b 05 70 f6 6e 7e mov %gs:0x7e6ef670(%rip),%eax # 0x7e6ef69a * 2a: 25 00 01 ff 00 and $0xff0100,%eax <-- trapping instruction 2f: 74 10 je 0x41 31: 3d 00 01 00 00 cmp $0x100,%eax 36: 75 57 jne 0x8f 38: 83 b9 1c 16 00 00 00 cmpl $0x0,0x161c(%rcx) 3f: 74 .byte 0x74