====================================================== WARNING: possible circular locking dependency detected 5.15.170-syzkaller #0 Not tainted ------------------------------------------------------ syz.1.2/4264 is trying to acquire lock: ffff88802a6e41b8 (&trie->lock){-...}-{2:2}, at: trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:450 but task is already holding lock: ffff8880b912a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1692 [inline] ffff8880b912a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x662/0xcf0 kernel/time/hrtimer.c:1752 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (hrtimer_bases.lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __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:173 [inline] hrtimer_start_range_ns+0x105/0xc80 kernel/time/hrtimer.c:1299 hrtimer_start include/linux/hrtimer.h:420 [inline] run_page_cache_worker kernel/rcu/tree.c:3488 [inline] kvfree_call_rcu+0x6a0/0x8a0 kernel/rcu/tree.c:3599 rtnl_register_internal+0x443/0x530 net/core/rtnetlink.c:223 rtnl_register+0x32/0x70 net/core/rtnetlink.c:273 ip_rt_init+0x2e6/0x390 net/ipv4/route.c:3750 ip_init+0xa/0x20 net/ipv4/ip_output.c:1749 inet_init+0x27c/0x390 net/ipv4/af_inet.c:2009 do_one_initcall+0x22b/0x7a0 init/main.c:1302 do_initcall_level+0x157/0x210 init/main.c:1375 do_initcalls+0x49/0x90 init/main.c:1391 kernel_init_freeable+0x425/0x5c0 init/main.c:1615 kernel_init+0x19/0x290 init/main.c:1506 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 -> #1 (krc.lock){....}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __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:3199 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3506 [inline] kvfree_call_rcu+0x1b5/0x8a0 kernel/rcu/tree.c:3597 trie_update_elem+0x808/0xc00 kernel/bpf/lpm_trie.c:384 bpf_map_update_value+0x5d7/0x6c0 kernel/bpf/syscall.c:221 generic_map_update_batch+0x54d/0x8b0 kernel/bpf/syscall.c:1421 bpf_map_do_batch+0x4d0/0x620 __sys_bpf+0x55c/0x670 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 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+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:450 bpf_prog_95bd9bbeeeeb8f2e+0x45/0x628 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1915 trace_hrtimer_start include/trace/events/timer.h:199 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x324/0x390 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1705 [inline] __hrtimer_run_queues+0x6b6/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 unwind_done arch/x86/include/asm/unwind.h:46 [inline] arch_stack_walk+0x114/0x140 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:711 [inline] fill_pool lib/debugobjects.c:172 [inline] __debug_object_init+0x77a/0xd30 lib/debugobjects.c:615 synchronize_rcu_expedited+0x3ea/0x740 kernel/rcu/tree_exp.h:855 synchronize_rcu+0x107/0x1a0 kernel/rcu/tree.c:3798 pptp_release+0x13b/0x2f0 drivers/net/ppp/pptp.c:517 __sock_release net/socket.c:649 [inline] sock_release+0x7a/0x140 net/socket.c:677 __sys_socketpair+0x6bd/0x700 __do_sys_socketpair net/socket.c:1695 [inline] __se_sys_socketpair net/socket.c:1692 [inline] __x64_sys_socketpair+0x97/0xb0 net/socket.c:1692 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 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 *** 4 locks held by syz.1.2/4264: #0: ffff888023007120 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1678 [inline] #0: ffff888023007120 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pptp_release+0x4e/0x2f0 drivers/net/ppp/pptp.c:508 #1: ffffffff8c924228 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8c924228 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845 #2: ffff8880b912a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1692 [inline] #2: ffff8880b912a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x662/0xcf0 kernel/time/hrtimer.c:1752 #3: ffffffff8c91fc60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 stack backtrace: CPU: 1 PID: 4264 Comm: syz.1.2 Not tainted 5.15.170-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 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+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:450 bpf_prog_95bd9bbeeeeb8f2e+0x45/0x628 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1915 trace_hrtimer_start include/trace/events/timer.h:199 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x324/0x390 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1705 [inline] __hrtimer_run_queues+0x6b6/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:arch_stack_walk+0x114/0x140 arch/x86/kernel/stacktrace.c:24 Code: ff 48 89 df e8 2d b6 08 00 48 85 c0 74 1e 4c 89 f7 48 89 c6 41 ff d5 84 c0 74 11 48 89 df e8 33 b7 08 00 83 bd 70 ff ff ff 00 <75> d5 65 48 8b 04 25 28 00 00 00 48 3b 45 d0 75 0f 48 83 c4 68 5b RSP: 0018:ffffc900031773c0 EFLAGS: 00000202 RAX: 0000000080000001 RBX: ffffc900031773c0 RCX: 0000000080000000 RDX: dffffc0000000000 RSI: ffffc900031779f0 RDI: 0000000000000001 RBP: ffffc90003177450 R08: ffffc900031779f0 R09: ffffc90003177410 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88802278d940 R13: ffffffff816e0990 R14: ffffc900031774a0 R15: 0000000000000000 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:711 [inline] fill_pool lib/debugobjects.c:172 [inline] __debug_object_init+0x77a/0xd30 lib/debugobjects.c:615 synchronize_rcu_expedited+0x3ea/0x740 kernel/rcu/tree_exp.h:855 synchronize_rcu+0x107/0x1a0 kernel/rcu/tree.c:3798 pptp_release+0x13b/0x2f0 drivers/net/ppp/pptp.c:517 __sock_release net/socket.c:649 [inline] sock_release+0x7a/0x140 net/socket.c:677 __sys_socketpair+0x6bd/0x700 __do_sys_socketpair net/socket.c:1695 [inline] __se_sys_socketpair net/socket.c:1692 [inline] __x64_sys_socketpair+0x97/0xb0 net/socket.c:1692 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f3ed2b8a719 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:00007f3ed1002038 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 00007f3ed2d41f80 RCX: 00007f3ed2b8a719 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000018 RBP: 00007f3ed2bfd32e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3ed2d41f80 R15: 00007ffc8df23258 ---------------- Code disassembly (best guess): 0: ff 48 89 decl -0x77(%rax) 3: df e8 fucomip %st(0),%st 5: 2d b6 08 00 48 sub $0x480008b6,%eax a: 85 c0 test %eax,%eax c: 74 1e je 0x2c e: 4c 89 f7 mov %r14,%rdi 11: 48 89 c6 mov %rax,%rsi 14: 41 ff d5 call *%r13 17: 84 c0 test %al,%al 19: 74 11 je 0x2c 1b: 48 89 df mov %rbx,%rdi 1e: e8 33 b7 08 00 call 0x8b756 23: 83 bd 70 ff ff ff 00 cmpl $0x0,-0x90(%rbp) * 2a: 75 d5 jne 0x1 <-- trapping instruction 2c: 65 48 8b 04 25 28 00 mov %gs:0x28,%rax 33: 00 00 35: 48 3b 45 d0 cmp -0x30(%rbp),%rax 39: 75 0f jne 0x4a 3b: 48 83 c4 68 add $0x68,%rsp 3f: 5b pop %rbx