====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.1028/7985 is trying to acquire lock: ffff88804a4e1238 (&trie->lock){....}-{2:2}, at: trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467 but task is already holding lock: ffff8880b902a258 (hrtimer_bases.lock){-.-.}-{2:2}, at: lock_hrtimer_base kernel/time/hrtimer.c:168 [inline] ffff8880b902a258 (hrtimer_bases.lock){-.-.}-{2:2}, at: hrtimer_start_range_ns+0xff/0xc20 kernel/time/hrtimer.c:1284 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (hrtimer_bases.lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 lock_hrtimer_base kernel/time/hrtimer.c:168 [inline] hrtimer_start_range_ns+0xff/0xc20 kernel/time/hrtimer.c:1284 hrtimer_start include/linux/hrtimer.h:420 [inline] run_page_cache_worker kernel/rcu/tree.c:3492 [inline] kvfree_call_rcu+0x61b/0x7d0 kernel/rcu/tree.c:3603 rtnl_register_internal+0x489/0x590 net/core/rtnetlink.c:225 rtnl_register+0x2e/0x70 net/core/rtnetlink.c:275 ip_rt_init+0x2e0/0x3a0 net/ipv4/route.c:3803 ip_init+0xa/0x20 net/ipv4/ip_output.c:1758 inet_init+0x28b/0x3a0 net/ipv4/af_inet.c:2007 do_one_initcall+0x272/0x730 init/main.c:1316 do_initcall_level+0x137/0x1f0 init/main.c:1389 do_initcalls+0x4b/0x90 init/main.c:1405 kernel_init_freeable+0x3e9/0x570 init/main.c:1629 kernel_init+0x19/0x1b0 init/main.c:1520 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 -> #1 (krc.lock){..-.}-{2:2}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:3203 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3510 [inline] kvfree_call_rcu+0x18d/0x7d0 kernel/rcu/tree.c:3601 trie_update_elem+0x86c/0xc50 kernel/bpf/lpm_trie.c:396 bpf_map_update_value+0x57d/0x650 kernel/bpf/syscall.c:223 map_update_elem+0x626/0x770 kernel/bpf/syscall.c:1194 __sys_bpf+0x46b/0x6f0 kernel/bpf/syscall.c:4645 __do_sys_bpf kernel/bpf/syscall.c:4761 [inline] __se_sys_bpf kernel/bpf/syscall.c:4759 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&trie->lock){....}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467 bpf_prog_d6ce680b99a28260+0x42/0x98 bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] BPF_PROG_RUN_ARRAY include/linux/bpf.h:1439 [inline] trace_call_bpf+0x2b1/0x5b0 kernel/trace/bpf_trace.c:127 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10016 perf_trace_lock_acquire+0x340/0x3e0 include/trace/events/lock.h:13 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x3d7/0x400 kernel/locking/lockdep.c:5594 seqcount_lockdep_reader_access+0xcd/0x1d0 include/linux/seqlock.h:103 ktime_get+0x31/0x270 kernel/time/timekeeping.c:829 __hrtimer_start_range_ns kernel/time/hrtimer.c:1230 [inline] hrtimer_start_range_ns+0x338/0xc20 kernel/time/hrtimer.c:1286 hrtimer_start_expires include/linux/hrtimer.h:434 [inline] hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1947 [inline] do_nanosleep+0x1a1/0x770 kernel/time/hrtimer.c:2023 hrtimer_nanosleep+0x33e/0x590 kernel/time/hrtimer.c:2079 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1314 [inline] __se_sys_clock_nanosleep+0x30b/0x3a0 kernel/time/posix-timers.c:1291 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Chain exists of: &trie->lock --> krc.lock --> hrtimer_bases.lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(hrtimer_bases.lock); lock(krc.lock); lock(hrtimer_bases.lock); lock(&trie->lock); *** DEADLOCK *** 2 locks held by syz.1.1028/7985: #0: ffff8880b902a258 (hrtimer_bases.lock){-.-.}-{2:2}, at: lock_hrtimer_base kernel/time/hrtimer.c:168 [inline] #0: ffff8880b902a258 (hrtimer_bases.lock){-.-.}-{2:2}, at: hrtimer_start_range_ns+0xff/0xc20 kernel/time/hrtimer.c:1284 #1: ffffffff8c31f320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:312 stack backtrace: CPU: 0 PID: 7985 Comm: syz.1.1028 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467 bpf_prog_d6ce680b99a28260+0x42/0x98 bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] BPF_PROG_RUN_ARRAY include/linux/bpf.h:1439 [inline] trace_call_bpf+0x2b1/0x5b0 kernel/trace/bpf_trace.c:127 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10016 perf_trace_lock_acquire+0x340/0x3e0 include/trace/events/lock.h:13 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x3d7/0x400 kernel/locking/lockdep.c:5594 seqcount_lockdep_reader_access+0xcd/0x1d0 include/linux/seqlock.h:103 ktime_get+0x31/0x270 kernel/time/timekeeping.c:829 __hrtimer_start_range_ns kernel/time/hrtimer.c:1230 [inline] hrtimer_start_range_ns+0x338/0xc20 kernel/time/hrtimer.c:1286 hrtimer_start_expires include/linux/hrtimer.h:434 [inline] hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1947 [inline] do_nanosleep+0x1a1/0x770 kernel/time/hrtimer.c:2023 hrtimer_nanosleep+0x33e/0x590 kernel/time/hrtimer.c:2079 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1314 [inline] __se_sys_clock_nanosleep+0x30b/0x3a0 kernel/time/posix-timers.c:1291 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f43722c568e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007ffe45a550c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 0000555562425500 RCX: 00007f43722c568e RDX: 00007ffe45a55120 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f437257fda0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000002f3b4 R13: 00007f437257e09c R14: 000000000002f17d R15: 00007f437257e090