====================================================== WARNING: possible circular locking dependency detected 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0 Not tainted ------------------------------------------------------ syz-fuzzer/5202 is trying to acquire lock: ffff88806b129558 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:3298 [inline] ffff88806b129558 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3697 [inline] ffff88806b129558 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0xda/0xbe0 kernel/rcu/tree.c:3782 but task is already holding lock: ffff88806b12a858 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5d/0x220 kernel/time/timer.c:1051 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&base->lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 lock_timer_base+0x5d/0x220 kernel/time/timer.c:1051 __mod_timer+0x426/0xdc0 kernel/time/timer.c:1132 add_timer_global+0x8a/0xc0 kernel/time/timer.c:1330 __queue_delayed_work+0x1ba/0x2e0 kernel/workqueue.c:2543 queue_delayed_work_on+0x12a/0x150 kernel/workqueue.c:2572 kvfree_call_rcu+0x749/0xbe0 kernel/rcu/tree.c:3810 rtnl_register_internal+0x343/0x670 net/core/rtnetlink.c:265 rtnl_register+0x34/0x80 net/core/rtnetlink.c:315 ip_rt_init+0x34a/0x450 net/ipv4/route.c:3696 ip_init+0xe/0x20 net/ipv4/ip_output.c:1663 inet_init+0x3f0/0x6f0 net/ipv4/af_inet.c:1983 do_one_initcall+0x128/0x700 init/main.c:1267 do_initcall_level init/main.c:1329 [inline] do_initcalls init/main.c:1345 [inline] do_basic_setup init/main.c:1364 [inline] kernel_init_freeable+0x69d/0xca0 init/main.c:1578 kernel_init+0x1c/0x2b0 init/main.c:1467 ret_from_fork+0x45/0x80 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:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __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:3298 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3697 [inline] kvfree_call_rcu+0xda/0xbe0 kernel/rcu/tree.c:3782 trie_delete_elem+0x5c5/0x820 kernel/bpf/lpm_trie.c:540 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2012 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2253 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2444 __bpf_trace_timer_start+0xc7/0x100 include/trace/events/timer.h:52 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x2b4/0x550 kernel/time/timer.c:663 __mod_timer+0xada/0xdc0 kernel/time/timer.c:1181 sk_reset_timer+0x21/0xc0 net/core/sock.c:3419 tcp_rearm_rto+0xd2/0x100 net/ipv4/tcp_input.c:3230 tcp_event_new_data_sent+0x329/0x3f0 net/ipv4/tcp_output.c:83 tcp_write_xmit+0x12c9/0x8480 net/ipv4/tcp_output.c:2836 __tcp_push_pending_frames+0xaf/0x390 net/ipv4/tcp_output.c:3014 tcp_push_pending_frames include/net/tcp.h:2102 [inline] tcp_data_snd_check net/ipv4/tcp_input.c:5660 [inline] tcp_rcv_established+0xe32/0x21b0 net/ipv4/tcp_input.c:6088 tcp_v4_do_rcv+0x707/0xab0 net/ipv4/tcp_ipv4.c:1909 sk_backlog_rcv include/net/sock.h:1106 [inline] __release_sock+0x31b/0x400 net/core/sock.c:2983 release_sock+0x5a/0x220 net/core/sock.c:3549 tcp_sendmsg+0x38/0x50 net/ipv4/tcp.c:1352 inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:853 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_write_iter+0x4b8/0x5c0 net/socket.c:1160 new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6b6/0x1140 fs/read_write.c:590 ksys_write+0x1f8/0x260 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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 *** 3 locks held by syz-fuzzer/5202: #0: ffff8880268e0258 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1602 [inline] #0: ffff8880268e0258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x20/0x50 net/ipv4/tcp.c:1350 #1: ffff88806b12a858 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5d/0x220 kernel/time/timer.c:1051 #2: ffffffff8dbb1920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8dbb1920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8dbb1920 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #2: ffffffff8dbb1920 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2444 stack backtrace: CPU: 1 PID: 5202 Comm: syz-fuzzer Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __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:3298 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3697 [inline] kvfree_call_rcu+0xda/0xbe0 kernel/rcu/tree.c:3782 trie_delete_elem+0x5c5/0x820 kernel/bpf/lpm_trie.c:540 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2012 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2253 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2444 __bpf_trace_timer_start+0xc7/0x100 include/trace/events/timer.h:52 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x2b4/0x550 kernel/time/timer.c:663 __mod_timer+0xada/0xdc0 kernel/time/timer.c:1181 sk_reset_timer+0x21/0xc0 net/core/sock.c:3419 tcp_rearm_rto+0xd2/0x100 net/ipv4/tcp_input.c:3230 tcp_event_new_data_sent+0x329/0x3f0 net/ipv4/tcp_output.c:83 tcp_write_xmit+0x12c9/0x8480 net/ipv4/tcp_output.c:2836 __tcp_push_pending_frames+0xaf/0x390 net/ipv4/tcp_output.c:3014 tcp_push_pending_frames include/net/tcp.h:2102 [inline] tcp_data_snd_check net/ipv4/tcp_input.c:5660 [inline] tcp_rcv_established+0xe32/0x21b0 net/ipv4/tcp_input.c:6088 tcp_v4_do_rcv+0x707/0xab0 net/ipv4/tcp_ipv4.c:1909 sk_backlog_rcv include/net/sock.h:1106 [inline] __release_sock+0x31b/0x400 net/core/sock.c:2983 release_sock+0x5a/0x220 net/core/sock.c:3549 tcp_sendmsg+0x38/0x50 net/ipv4/tcp.c:1352 inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:853 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_write_iter+0x4b8/0x5c0 net/socket.c:1160 new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6b6/0x1140 fs/read_write.c:590 ksys_write+0x1f8/0x260 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x40720e Code: 48 83 ec 38 e8 13 00 00 00 48 83 c4 38 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 f2 48 89 fa 48 89 ce 48 89 df 0f 05 <48> 3d 01 f0 ff ff 76 15 48 f7 d8 48 89 c1 48 c7 c0 ff ff ff ff 48 RSP: 002b:000000c00041ee00 EFLAGS: 00000212 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000040720e RDX: 00000000000000f0 RSI: 000000c001228980 RDI: 0000000000000003 RBP: 000000c00041ee40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 000000c00041ef80 R13: 0000000000000000 R14: 000000c0000061a0 R15: 0000000000000010