====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc6-syzkaller-g44d0469f79bd #0 Not tainted ------------------------------------------------------ syz.1.482/7384 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: ffff8880b862c898 (hrtimer_bases.lock){-.-.}-{2:2}, at: lock_hrtimer_base kernel/time/hrtimer.c:175 [inline] ffff8880b862c898 (hrtimer_bases.lock){-.-.}-{2:2}, at: hrtimer_start_range_ns+0x109/0xca0 kernel/time/hrtimer.c:1300 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (hrtimer_bases.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_hrtimer_base kernel/time/hrtimer.c:175 [inline] hrtimer_start_range_ns+0x109/0xca0 kernel/time/hrtimer.c:1300 hrtimer_start include/linux/hrtimer.h:275 [inline] run_page_cache_worker kernel/rcu/tree.c:3707 [inline] kvfree_call_rcu+0x5e6/0x790 kernel/rcu/tree.c:3813 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_hrtimer_start include/trace/events/timer.h:222 [inline] debug_activate kernel/time/hrtimer.c:479 [inline] enqueue_hrtimer+0x35a/0x3c0 kernel/time/hrtimer.c:1085 __hrtimer_start_range_ns kernel/time/hrtimer.c:1260 [inline] hrtimer_start_range_ns+0xac8/0xca0 kernel/time/hrtimer.c:1302 hrtimer_start include/linux/hrtimer.h:275 [inline] start_dl_timer+0x36a/0x4d0 kernel/sched/deadline.c:1170 update_curr_dl_se+0x340/0x840 kernel/sched/deadline.c:1519 update_curr+0x56c/0xdb0 kernel/sched/fair.c:1245 entity_tick kernel/sched/fair.c:5667 [inline] task_tick_fair+0xce/0x7c0 kernel/sched/fair.c:13056 sched_tick+0x219/0x610 kernel/sched/core.c:5606 update_process_times+0x202/0x230 kernel/time/timer.c:2524 tick_sched_handle kernel/time/tick-sched.c:276 [inline] tick_nohz_handler+0x37c/0x500 kernel/time/tick-sched.c:297 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x551/0xd50 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5829 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock_sched include/linux/rcupdate.h:941 [inline] pfn_valid+0x113/0x450 include/linux/mmzone.h:2042 page_table_check_clear+0x1e/0x550 mm/page_table_check.c:70 get_and_clear_full_ptes include/linux/pgtable.h:684 [inline] zap_present_folio_ptes mm/memory.c:1496 [inline] zap_present_ptes mm/memory.c:1579 [inline] zap_pte_range mm/memory.c:1621 [inline] zap_pmd_range mm/memory.c:1739 [inline] zap_pud_range mm/memory.c:1768 [inline] zap_p4d_range mm/memory.c:1789 [inline] unmap_page_range+0x2a13/0x40e0 mm/memory.c:1810 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1900 exit_mmap+0x275/0xc40 mm/mmap.c:1913 __mmput+0x115/0x390 kernel/fork.c:1348 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x28e0 kernel/exit.c:926 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(hrtimer_bases.lock); lock(krc.lock); lock(hrtimer_bases.lock); lock(krc.lock); *** DEADLOCK *** 7 locks held by syz.1.482/7384: #0: ffff88807fa93a98 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:144 [inline] #0: ffff88807fa93a98 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x165/0xc40 mm/mmap.c:1897 #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: __pte_offset_map+0x82/0x380 mm/pgtable-generic.c:287 #2: ffff88802e7fc7f8 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff88802e7fc7f8 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: __pte_offset_map_lock+0x1ba/0x300 mm/pgtable-generic.c:375 #3: ffffffff8e937d20 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #3: ffffffff8e937d20 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:941 [inline] #3: ffffffff8e937d20 (rcu_read_lock_sched){....}-{1:2}, at: pfn_valid+0xf6/0x450 include/linux/mmzone.h:2042 #4: ffff8880b863ea98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 #5: ffff8880b862c898 (hrtimer_bases.lock){-.-.}-{2:2}, at: lock_hrtimer_base kernel/time/hrtimer.c:175 [inline] #5: ffff8880b862c898 (hrtimer_bases.lock){-.-.}-{2:2}, at: hrtimer_start_range_ns+0x109/0xca0 kernel/time/hrtimer.c:1300 #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: 7384 Comm: syz.1.482 Not tainted 6.12.0-rc6-syzkaller-g44d0469f79bd #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_hrtimer_start include/trace/events/timer.h:222 [inline] debug_activate kernel/time/hrtimer.c:479 [inline] enqueue_hrtimer+0x35a/0x3c0 kernel/time/hrtimer.c:1085 __hrtimer_start_range_ns kernel/time/hrtimer.c:1260 [inline] hrtimer_start_range_ns+0xac8/0xca0 kernel/time/hrtimer.c:1302 hrtimer_start include/linux/hrtimer.h:275 [inline] start_dl_timer+0x36a/0x4d0 kernel/sched/deadline.c:1170 update_curr_dl_se+0x340/0x840 kernel/sched/deadline.c:1519 update_curr+0x56c/0xdb0 kernel/sched/fair.c:1245 entity_tick kernel/sched/fair.c:5667 [inline] task_tick_fair+0xce/0x7c0 kernel/sched/fair.c:13056 sched_tick+0x219/0x610 kernel/sched/core.c:5606 update_process_times+0x202/0x230 kernel/time/timer.c:2524 tick_sched_handle kernel/time/tick-sched.c:276 [inline] tick_nohz_handler+0x37c/0x500 kernel/time/tick-sched.c:297 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x551/0xd50 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5829 Code: 2b 00 74 08 4c 89 f7 e8 8a 56 8e 00 f6 44 24 61 02 0f 85 85 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: 0018:ffffc9000342f120 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000685e30 RCX: 7616b28917880800 RDX: dffffc0000000000 RSI: ffffffff8c0adc40 RDI: ffffffff8c610860 RBP: ffffc9000342f270 R08: ffffffff942cd807 R09: 1ffffffff2859b00 R10: dffffc0000000000 R11: fffffbfff2859b01 R12: 1ffff92000685e2c R13: dffffc0000000000 R14: ffffc9000342f180 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock_sched include/linux/rcupdate.h:941 [inline] pfn_valid+0x113/0x450 include/linux/mmzone.h:2042 page_table_check_clear+0x1e/0x550 mm/page_table_check.c:70 get_and_clear_full_ptes include/linux/pgtable.h:684 [inline] zap_present_folio_ptes mm/memory.c:1496 [inline] zap_present_ptes mm/memory.c:1579 [inline] zap_pte_range mm/memory.c:1621 [inline] zap_pmd_range mm/memory.c:1739 [inline] zap_pud_range mm/memory.c:1768 [inline] zap_p4d_range mm/memory.c:1789 [inline] unmap_page_range+0x2a13/0x40e0 mm/memory.c:1810 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1900 exit_mmap+0x275/0xc40 mm/mmap.c:1913 __mmput+0x115/0x390 kernel/fork.c:1348 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x28e0 kernel/exit.c:926 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f748e77e719 Code: Unable to access opcode bytes at 0x7f748e77e6ef. RSP: 002b:00007f748cbf60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f748e936060 RCX: 00007f748e77e719 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f748e936060 RBP: 00007f748e936058 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f748e936064 R13: 0000000000000000 R14: 00007ffe102242d0 R15: 00007ffe102243b8 ---------------- Code disassembly (best guess): 0: 2b 00 sub (%rax),%eax 2: 74 08 je 0xc 4: 4c 89 f7 mov %r14,%rdi 7: e8 8a 56 8e 00 call 0x8e5696 c: f6 44 24 61 02 testb $0x2,0x61(%rsp) 11: 0f 85 85 01 00 00 jne 0x19c 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