====================================================== WARNING: possible circular locking dependency detected 6.10.0-rc4-syzkaller-00148-g50736169ecc8 #0 Not tainted ------------------------------------------------------ syz-executor.5/5119 is trying to acquire lock: ffff8880b9329558 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:3298 [inline] ffff8880b9329558 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3697 [inline] ffff8880b9329558 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0xda/0xbe0 kernel/rcu/tree.c:3782 but task is already holding lock: ffff8880b932a858 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5d/0x220 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}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 lock_timer_base+0x5d/0x220 kernel/time/timer.c:1051 __mod_timer+0x426/0xdc0 kernel/time/timer.c:1132 add_timer_global+0x8a/0xc0 kernel/time/timer.c:1330 __queue_delayed_work+0x1ba/0x2e0 kernel/workqueue.c:2543 queue_delayed_work_on+0x12a/0x150 kernel/workqueue.c:2572 kvfree_call_rcu+0x749/0xbe0 kernel/rcu/tree.c:3810 rtnl_register_internal+0x343/0x670 net/core/rtnetlink.c:265 rtnl_register+0x34/0x80 net/core/rtnetlink.c:315 ip_rt_init+0x34a/0x450 net/ipv4/route.c:3696 ip_init+0xe/0x20 net/ipv4/ip_output.c:1663 inet_init+0x3f0/0x6f0 net/ipv4/af_inet.c:1983 do_one_initcall+0x12b/0x700 init/main.c:1267 do_initcall_level init/main.c:1329 [inline] do_initcalls init/main.c:1345 [inline] do_basic_setup init/main.c:1364 [inline] kernel_init_freeable+0x69d/0xca0 init/main.c:1578 kernel_init+0x1c/0x2b0 init/main.c:1467 ret_from_fork+0x48/0x80 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:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __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:3298 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3697 [inline] kvfree_call_rcu+0xda/0xbe0 kernel/rcu/tree.c:3782 trie_delete_elem+0x5c5/0x820 kernel/bpf/lpm_trie.c:540 bpf_prog_1db1603a7cfa36fb+0x45/0x4d bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run2+0x234/0x590 kernel/trace/bpf_trace.c:2444 __bpf_trace_timer_start+0xc7/0x100 include/trace/events/timer.h:52 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x2b4/0x550 kernel/time/timer.c:663 internal_add_timer kernel/time/timer.c:688 [inline] __mod_timer+0x8d7/0xdc0 kernel/time/timer.c:1183 add_timer+0x62/0x90 kernel/time/timer.c:1296 dsp_cmx_send+0xc30/0x1760 drivers/isdn/mISDN/dsp_cmx.c:1839 call_timer_fn+0x1a3/0x610 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers+0x74b/0xaf0 kernel/time/timer.c:2417 __run_timer_base kernel/time/timer.c:2428 [inline] __run_timer_base kernel/time/timer.c:2421 [inline] run_timer_base+0x111/0x190 kernel/time/timer.c:2437 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2447 handle_softirqs+0x219/0x8f0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5830 lookup_page_ext mm/page_ext.c:253 [inline] page_ext_get+0x132/0x310 mm/page_ext.c:522 page_table_check_set mm/page_table_check.c:114 [inline] page_table_check_set+0x279/0x9b0 mm/page_table_check.c:102 __page_table_check_ptes_set+0x2d0/0x3e0 mm/page_table_check.c:225 page_table_check_ptes_set include/linux/page_table_check.h:74 [inline] set_ptes include/linux/pgtable.h:267 [inline] __copy_present_ptes mm/memory.c:955 [inline] copy_present_ptes mm/memory.c:1038 [inline] copy_pte_range mm/memory.c:1153 [inline] copy_pmd_range mm/memory.c:1240 [inline] copy_pud_range mm/memory.c:1277 [inline] copy_p4d_range mm/memory.c:1301 [inline] copy_page_range+0x1dc2/0x5640 mm/memory.c:1399 dup_mmap kernel/fork.c:751 [inline] dup_mm kernel/fork.c:1688 [inline] copy_mm kernel/fork.c:1737 [inline] copy_process+0x83c6/0x8f10 kernel/fork.c:2390 kernel_clone+0xfd/0x980 kernel/fork.c:2797 __do_sys_clone+0xba/0x100 kernel/fork.c:2940 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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 *** 12 locks held by syz-executor.5/5119: #0: ffffffff8dcc45f0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:637 [inline] #0: ffffffff8dcc45f0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1688 [inline] #0: ffffffff8dcc45f0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm kernel/fork.c:1737 [inline] #0: ffffffff8dcc45f0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_process+0x6ab9/0x8f10 kernel/fork.c:2390 #1: ffff88802d2a3118 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:122 [inline] #1: ffff88802d2a3118 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:638 [inline] #1: ffff88802d2a3118 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1688 [inline] #1: ffff88802d2a3118 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm kernel/fork.c:1737 [inline] #1: ffff88802d2a3118 (&mm->mmap_lock){++++}-{3:3}, at: copy_process+0x6adf/0x8f10 kernel/fork.c:2390 #2: ffff88802c360b18 (&mm->mmap_lock/1){+.+.}-{3:3}, at: mmap_write_lock_nested include/linux/mmap_lock.h:113 [inline] #2: ffff88802c360b18 (&mm->mmap_lock/1){+.+.}-{3:3}, at: dup_mmap kernel/fork.c:647 [inline] #2: ffff88802c360b18 (&mm->mmap_lock/1){+.+.}-{3:3}, at: dup_mm kernel/fork.c:1688 [inline] #2: ffff88802c360b18 (&mm->mmap_lock/1){+.+.}-{3:3}, at: copy_mm kernel/fork.c:1737 [inline] #2: ffff88802c360b18 (&mm->mmap_lock/1){+.+.}-{3:3}, at: copy_process+0x6b3f/0x8f10 kernel/fork.c:2390 #3: ffffffff8dbb5be0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8dbb5be0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8dbb5be0 (rcu_read_lock){....}-{1:2}, at: __pte_offset_map+0x42/0x540 mm/pgtable-generic.c:287 #4: ffff88801fb85b58 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #4: ffff88801fb85b58 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: __pte_offset_map_lock+0xf1/0x300 mm/pgtable-generic.c:375 #5: ffffffff8dbb5be0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #5: ffffffff8dbb5be0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #5: ffffffff8dbb5be0 (rcu_read_lock){....}-{1:2}, at: __pte_offset_map+0x42/0x540 mm/pgtable-generic.c:287 #6: ffff88807e3082b8 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_pte_range mm/memory.c:1105 [inline] #6: ffff88807e3082b8 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_pmd_range mm/memory.c:1240 [inline] #6: ffff88807e3082b8 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_pud_range mm/memory.c:1277 [inline] #6: ffff88807e3082b8 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_p4d_range mm/memory.c:1301 [inline] #6: ffff88807e3082b8 (ptlock_ptr(ptdesc)#2/1){+.+.}-{2:2}, at: copy_page_range+0xcfb/0x5640 mm/memory.c:1399 #7: ffffffff8dbb5be0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #7: ffffffff8dbb5be0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #7: ffffffff8dbb5be0 (rcu_read_lock){....}-{1:2}, at: page_ext_get+0x34/0x310 mm/page_ext.c:521 #8: ffffc90000a18cb0 ((&dsp_spl_tl)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x610 kernel/time/timer.c:1789 #9: ffffffff8f368598 (dsp_lock){..-.}-{2:2}, at: dsp_cmx_send+0x23/0x1760 drivers/isdn/mISDN/dsp_cmx.c:1632 #10: ffff8880b932a858 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5d/0x220 kernel/time/timer.c:1051 #11: ffffffff8dbb5be0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #11: ffffffff8dbb5be0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #11: ffffffff8dbb5be0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #11: ffffffff8dbb5be0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2444 stack backtrace: CPU: 1 PID: 5119 Comm: syz-executor.5 Not tainted 6.10.0-rc4-syzkaller-00148-g50736169ecc8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __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:3298 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3697 [inline] kvfree_call_rcu+0xda/0xbe0 kernel/rcu/tree.c:3782 trie_delete_elem+0x5c5/0x820 kernel/bpf/lpm_trie.c:540 bpf_prog_1db1603a7cfa36fb+0x45/0x4d bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run2+0x234/0x590 kernel/trace/bpf_trace.c:2444 __bpf_trace_timer_start+0xc7/0x100 include/trace/events/timer.h:52 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x2b4/0x550 kernel/time/timer.c:663 internal_add_timer kernel/time/timer.c:688 [inline] __mod_timer+0x8d7/0xdc0 kernel/time/timer.c:1183 add_timer+0x62/0x90 kernel/time/timer.c:1296 dsp_cmx_send+0xc30/0x1760 drivers/isdn/mISDN/dsp_cmx.c:1839 call_timer_fn+0x1a3/0x610 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers+0x74b/0xaf0 kernel/time/timer.c:2417 __run_timer_base kernel/time/timer.c:2428 [inline] __run_timer_base kernel/time/timer.c:2421 [inline] run_timer_base+0x111/0x190 kernel/time/timer.c:2437 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2447 handle_softirqs+0x219/0x8f0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5830 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 ac 62 1a 75 83 f8 01 75 2d 9c 58 f6 c4 02 75 43 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f e9 42 18 28 00 45 31 ed eb RSP: 0018:ffffc90002f5f6a0 EFLAGS: 00000296 RAX: 0000000000000046 RBX: ffff888026886558 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8b2cc4a0 RDI: ffffffff8b901f80 RBP: ffffffff8dbb5be0 R08: 0000000000000007 R09: 000000000007ffff R10: 000000000000000d R11: 0000000000000007 R12: ffff888026885a00 R13: 0000000000000001 R14: 00000000ffffffff R15: 0000000000000003 lookup_page_ext mm/page_ext.c:253 [inline] page_ext_get+0x132/0x310 mm/page_ext.c:522 page_table_check_set mm/page_table_check.c:114 [inline] page_table_check_set+0x279/0x9b0 mm/page_table_check.c:102 __page_table_check_ptes_set+0x2d0/0x3e0 mm/page_table_check.c:225 page_table_check_ptes_set include/linux/page_table_check.h:74 [inline] set_ptes include/linux/pgtable.h:267 [inline] __copy_present_ptes mm/memory.c:955 [inline] copy_present_ptes mm/memory.c:1038 [inline] copy_pte_range mm/memory.c:1153 [inline] copy_pmd_range mm/memory.c:1240 [inline] copy_pud_range mm/memory.c:1277 [inline] copy_p4d_range mm/memory.c:1301 [inline] copy_page_range+0x1dc2/0x5640 mm/memory.c:1399 dup_mmap kernel/fork.c:751 [inline] dup_mm kernel/fork.c:1688 [inline] copy_mm kernel/fork.c:1737 [inline] copy_process+0x83c6/0x8f10 kernel/fork.c:2390 kernel_clone+0xfd/0x980 kernel/fork.c:2797 __do_sys_clone+0xba/0x100 kernel/fork.c:2940 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1b9d079f53 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007fffe268dd28 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1b9d079f53 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000555592016750 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: b8 ff ff ff ff mov $0xffffffff,%eax 7: 65 0f c1 05 ac 62 1a xadd %eax,%gs:0x751a62ac(%rip) # 0x751a62bb e: 75 f: 83 f8 01 cmp $0x1,%eax 12: 75 2d jne 0x41 14: 9c pushf 15: 58 pop %rax 16: f6 c4 02 test $0x2,%ah 19: 75 43 jne 0x5e 1b: 48 f7 04 24 00 02 00 testq $0x200,(%rsp) 22: 00 23: 74 01 je 0x26 25: fb sti 26: 48 83 c4 08 add $0x8,%rsp * 2a: 44 89 e8 mov %r13d,%eax <-- trapping instruction 2d: 5b pop %rbx 2e: 5d pop %rbp 2f: 41 5c pop %r12 31: 41 5d pop %r13 33: 41 5e pop %r14 35: 41 5f pop %r15 37: e9 42 18 28 00 jmp 0x28187e 3c: 45 31 ed xor %r13d,%r13d 3f: eb .byte 0xeb