====================================================== WARNING: possible circular locking dependency detected 6.1.126-syzkaller #0 Not tainted ------------------------------------------------------ syz.3.487/5946 is trying to acquire lock: ffff8880b8f28118 (krc.lock){-.-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] ffff8880b8f28118 (krc.lock){-.-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] ffff8880b8f28118 (krc.lock){-.-.}-{2:2}, at: kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3402 but task is already holding lock: ffff8880b8f2a4d8 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1693 [inline] ffff8880b8f2a4d8 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x6d3/0xe50 kernel/time/hrtimer.c:1753 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (hrtimer_bases.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_hrtimer_base kernel/time/hrtimer.c:174 [inline] hrtimer_start_range_ns+0x105/0xc80 kernel/time/hrtimer.c:1300 hrtimer_start include/linux/hrtimer.h:420 [inline] run_page_cache_worker kernel/rcu/tree.c:3293 [inline] kvfree_call_rcu+0x72b/0x8c0 kernel/rcu/tree.c:3404 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_2c29ac5cdc6b1842+0x3a/0x3e 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_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2323 trace_hrtimer_start include/trace/events/timer.h:202 [inline] debug_activate kernel/time/hrtimer.c:477 [inline] enqueue_hrtimer+0x382/0x410 kernel/time/hrtimer.c:1085 __run_hrtimer kernel/time/hrtimer.c:1706 [inline] __hrtimer_run_queues+0x728/0xe50 kernel/time/hrtimer.c:1753 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1815 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x158/0x5b0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 __sanitizer_cov_trace_const_cmp4+0x4/0x80 kernel/kcov.c:314 alloc_fd+0xc8/0x640 fs/file.c:489 __sys_socketpair+0x142/0x700 net/socket.c:1714 __do_sys_socketpair net/socket.c:1786 [inline] __se_sys_socketpair net/socket.c:1783 [inline] __x64_sys_socketpair+0x97/0xb0 net/socket.c:1783 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 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 *** 3 locks held by syz.3.487/5946: #0: ffff88807861a298 (&newf->file_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #0: ffff88807861a298 (&newf->file_lock){+.+.}-{2:2}, at: alloc_fd+0x62/0x640 fs/file.c:487 #1: ffff8880b8f2a4d8 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1693 [inline] #1: ffff8880b8f2a4d8 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x6d3/0xe50 kernel/time/hrtimer.c:1753 #2: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #2: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #2: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2283 [inline] #2: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x110/0x410 kernel/trace/bpf_trace.c:2323 stack backtrace: CPU: 1 PID: 5946 Comm: syz.3.487 Not tainted 6.1.126-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_2c29ac5cdc6b1842+0x3a/0x3e 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_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2323 trace_hrtimer_start include/trace/events/timer.h:202 [inline] debug_activate kernel/time/hrtimer.c:477 [inline] enqueue_hrtimer+0x382/0x410 kernel/time/hrtimer.c:1085 __run_hrtimer kernel/time/hrtimer.c:1706 [inline] __hrtimer_run_queues+0x728/0xe50 kernel/time/hrtimer.c:1753 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1815 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x158/0x5b0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:write_comp_data kernel/kcov.c:244 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x4/0x80 kernel/kcov.c:313 Code: 89 f8 89 f6 49 ff c2 4c 89 11 48 c7 44 0a 08 03 00 00 00 48 89 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 c3 0f 1f 00 4c 8b 04 24 <65> 48 8b 15 d4 cf 77 7e 65 8b 05 d5 cf 77 7e 25 00 01 ff 00 74 10 RSP: 0018:ffffc90003befd70 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffff888024f75940 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff88807861a218 R08: ffffffff81f944a8 R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff88807861a2c0 R15: ffff8880564ceb00 alloc_fd+0xc8/0x640 fs/file.c:489 __sys_socketpair+0x142/0x700 net/socket.c:1714 __do_sys_socketpair net/socket.c:1786 [inline] __se_sys_socketpair net/socket.c:1783 [inline] __x64_sys_socketpair+0x97/0xb0 net/socket.c:1783 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd253385d29 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd2541c0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 00007fd253575fa0 RCX: 00007fd253385d29 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000001 RBP: 00007fd253401b08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd253575fa0 R15: 00007ffc8221f258 ---------------- Code disassembly (best guess): 0: 89 f8 mov %edi,%eax 2: 89 f6 mov %esi,%esi 4: 49 ff c2 inc %r10 7: 4c 89 11 mov %r10,(%rcx) a: 48 c7 44 0a 08 03 00 movq $0x3,0x8(%rdx,%rcx,1) 11: 00 00 13: 48 89 44 0a 10 mov %rax,0x10(%rdx,%rcx,1) 18: 48 89 74 0a 18 mov %rsi,0x18(%rdx,%rcx,1) 1d: 4c 89 44 0a 20 mov %r8,0x20(%rdx,%rcx,1) 22: c3 ret 23: 0f 1f 00 nopl (%rax) 26: 4c 8b 04 24 mov (%rsp),%r8 * 2a: 65 48 8b 15 d4 cf 77 mov %gs:0x7e77cfd4(%rip),%rdx # 0x7e77d006 <-- trapping instruction 31: 7e 32: 65 8b 05 d5 cf 77 7e mov %gs:0x7e77cfd5(%rip),%eax # 0x7e77d00e 39: 25 00 01 ff 00 and $0xff0100,%eax 3e: 74 10 je 0x50