====================================================== WARNING: possible circular locking dependency detected 6.1.128-syzkaller #0 Not tainted ------------------------------------------------------ syz.6.3895/19876 is trying to acquire lock: ffff8880b8e28118 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] ffff8880b8e28118 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] ffff8880b8e28118 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3402 but task is already holding lock: ffff8880b8e28358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&base->lock){-.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __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:999 __mod_timer+0x1cb/0xee0 kernel/time/timer.c:1072 queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1704 queue_delayed_work include/linux/workqueue.h:527 [inline] schedule_delayed_monitor_work kernel/rcu/tree.c:3172 [inline] kvfree_call_rcu+0x520/0x8c0 kernel/rcu/tree.c:3428 rtnl_register_internal+0x489/0x580 net/core/rtnetlink.c:260 rtnl_register+0x32/0x70 net/core/rtnetlink.c:310 ip_rt_init+0x335/0x3c7 net/ipv4/route.c:3763 ip_init+0xa/0x14 net/ipv4/ip_output.c:1770 inet_init+0x2ae/0x3c0 net/ipv4/af_inet.c:2033 do_one_initcall+0x265/0x8f0 init/main.c:1298 do_initcall_level+0x157/0x207 init/main.c:1371 do_initcalls+0x49/0x86 init/main.c:1387 kernel_init_freeable+0x45c/0x60f init/main.c:1626 kernel_init+0x19/0x290 init/main.c:1514 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #0 (krc.lock){..-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3402 trie_delete_elem+0x53a/0x690 kernel/bpf/lpm_trie.c:545 bpf_prog_ae0c3e605f35524c+0x3d/0x41 bpf_dispatcher_nop_func include/linux/bpf.h:1000 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2324 trace_timer_start include/trace/events/timer.h:53 [inline] enqueue_timer+0x440/0x600 kernel/time/timer.c:609 __mod_timer+0x92b/0xee0 queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1704 queue_delayed_work include/linux/workqueue.h:527 [inline] srcu_funnel_gp_start kernel/rcu/srcutree.c:951 [inline] srcu_gp_start_if_needed+0xce5/0x1080 kernel/rcu/srcutree.c:1151 rcu_do_batch kernel/rcu/tree.c:2297 [inline] rcu_core+0xade/0x1820 kernel/rcu/tree.c:2557 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0x157/0x240 kernel/softirq.c:661 irq_exit_rcu+0x5/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock_sched include/linux/rcupdate.h:883 [inline] pfn_valid+0x113/0x440 include/linux/mmzone.h:1857 page_table_check_set+0x25/0x6d0 mm/page_table_check.c:108 page_table_check_pte_set include/linux/page_table_check.h:83 [inline] set_pte_at arch/x86/include/asm/pgtable.h:1009 [inline] do_set_pte+0x584/0x590 mm/memory.c:4424 filemap_map_pages+0xc7c/0x12c0 mm/filemap.c:3480 do_fault_around mm/memory.c:4598 [inline] do_read_fault mm/memory.c:4624 [inline] do_fault mm/memory.c:4758 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x33e0/0x5340 mm/memory.c:5292 do_user_addr_fault arch/x86/mm/fault.c:1340 [inline] handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x26f/0x620 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 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 *** 9 locks held by syz.6.3895/19876: #0: ffff888028c908d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff888028c908d8 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline] #0: ffff888028c908d8 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2e0 mm/memory.c:5382 #1: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #1: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: filemap_map_pages+0x277/0x12c0 mm/filemap.c:3443 #2: ffff88807ea8e1f8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff88807ea8e1f8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: filemap_map_pages+0x958/0x12c0 mm/filemap.c:3454 #3: ffffffff8d32b040 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #3: ffffffff8d32b040 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:883 [inline] #3: ffffffff8d32b040 (rcu_read_lock_sched){....}-{1:2}, at: pfn_valid+0xf6/0x440 include/linux/mmzone.h:1857 #4: ffffffff8d32b180 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #4: ffffffff8d32b180 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2291 [inline] #4: ffffffff8d32b180 (rcu_callback){....}-{0:0}, at: rcu_core+0xa6b/0x1820 kernel/rcu/tree.c:2557 #5: ffffffff8d371788 (tracepoint_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #5: ffffffff8d371788 (tracepoint_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #5: ffffffff8d371788 (tracepoint_srcu){....}-{0:0}, at: srcu_gp_start_if_needed+0x17f/0x1080 kernel/rcu/srcutree.c:1094 #6: ffffffff8d3714c8 (tracepoint_srcu.lock){....}-{2:2}, at: spin_lock_irqsave_ssp_contention+0x106/0x440 kernel/rcu/srcutree.c:378 #7: ffff8880b8e28358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999 #8: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #8: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #8: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2283 [inline] #8: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x146/0x440 kernel/trace/bpf_trace.c:2324 stack backtrace: CPU: 0 PID: 19876 Comm: syz.6.3895 Not tainted 6.1.128-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3402 trie_delete_elem+0x53a/0x690 kernel/bpf/lpm_trie.c:545 bpf_prog_ae0c3e605f35524c+0x3d/0x41 bpf_dispatcher_nop_func include/linux/bpf.h:1000 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2324 trace_timer_start include/trace/events/timer.h:53 [inline] enqueue_timer+0x440/0x600 kernel/time/timer.c:609 __mod_timer+0x92b/0xee0 queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1704 queue_delayed_work include/linux/workqueue.h:527 [inline] srcu_funnel_gp_start kernel/rcu/srcutree.c:951 [inline] srcu_gp_start_if_needed+0xce5/0x1080 kernel/rcu/srcutree.c:1151 rcu_do_batch kernel/rcu/tree.c:2297 [inline] rcu_core+0xade/0x1820 kernel/rcu/tree.c:2557 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0x157/0x240 kernel/softirq.c:661 irq_exit_rcu+0x5/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666 Code: 2b 00 74 08 4c 89 f7 e8 ff 8b 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0000:ffffc900049d77e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200093af08 RCX: 1ffff9200093aea8 RDX: dffffc0000000000 RSI: ffffffff8b0c14c0 RDI: ffffffff8b5e6980 RBP: ffffc900049d7928 R08: dffffc0000000000 R09: fffffbfff224a04d R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200093af04 R13: dffffc0000000000 R14: ffffc900049d7840 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock_sched include/linux/rcupdate.h:883 [inline] pfn_valid+0x113/0x440 include/linux/mmzone.h:1857 page_table_check_set+0x25/0x6d0 mm/page_table_check.c:108 page_table_check_pte_set include/linux/page_table_check.h:83 [inline] set_pte_at arch/x86/include/asm/pgtable.h:1009 [inline] do_set_pte+0x584/0x590 mm/memory.c:4424 filemap_map_pages+0xc7c/0x12c0 mm/filemap.c:3480 do_fault_around mm/memory.c:4598 [inline] do_read_fault mm/memory.c:4624 [inline] do_fault mm/memory.c:4758 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x33e0/0x5340 mm/memory.c:5292 do_user_addr_fault arch/x86/mm/fault.c:1340 [inline] handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x26f/0x620 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f4fde86d2fd Code: ff 48 83 e8 01 48 89 ee bf 01 00 00 00 48 c1 e0 0e 48 c1 ee 06 48 01 c8 48 89 e9 81 e6 ff 3f 00 00 48 c1 e9 03 83 e1 07 d3 e7 <40> 84 bc 06 20 20 00 00 0f 85 11 fd ff ff e9 c0 fd ff ff e8 0b 34 RSP: 002b:00007ffe009b5a60 EFLAGS: 00010202 RAX: 000000110c380000 RBX: 00007f4fdf6d5720 RCX: 0000000000000002 RDX: 00000000000012d0 RSI: 00000000000002cb RDI: 0000000000000004 RBP: ffffffff8ab0b2d0 R08: 00007f4fdeba6038 R09: 00007f4fdeb92000 R10: 00007f4fdddff008 R11: 0000000000000009 R12: 0000000000000009 R13: 0000000000000000 R14: ffffffff8ab0b52d R15: 0000000000000220 ---------------- Code disassembly (best guess): 0: 2b 00 sub (%rax),%eax 2: 74 08 je 0xc 4: 4c 89 f7 mov %r14,%rdi 7: e8 ff 8b 77 00 call 0x778c0b c: f6 44 24 61 02 testb $0x2,0x61(%rsp) 11: 0f 85 84 01 00 00 jne 0x19b 17: 41 f7 c7 00 02 00 00 test $0x200,%r15d 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 40 0e 36 movq $0x45e0360e,0x40(%rsp) 28: e0 45 * 2a: 4b c7 44 25 00 00 00 movq $0x0,0x0(%r13,%r12,1) <-- trapping instruction 31: 00 00 33: 43 c7 44 25 09 00 00 movl $0x0,0x9(%r13,%r12,1) 3a: 00 00 3c: 43 rex.XB 3d: c7 .byte 0xc7 3e: 44 rex.R 3f: 25 .byte 0x25