======================================================
WARNING: possible circular locking dependency detected
6.1.128-syzkaller #0 Not tainted
------------------------------------------------------
syz.0.12945/9957 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:
ffff8880b8f28358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&base->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_timer_base+0x120/0x260 kernel/time/timer.c:999
__mod_timer+0x1cb/0xee0 kernel/time/timer.c:1072
queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1704
queue_delayed_work include/linux/workqueue.h:527 [inline]
schedule_delayed_monitor_work kernel/rcu/tree.c:3172 [inline]
kvfree_call_rcu+0x520/0x8c0 kernel/rcu/tree.c:3428
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_run3+0x231/0x440 kernel/trace/bpf_trace.c:2324
__traceiter_timer_start+0x79/0xd0 include/trace/events/timer.h:53
trace_timer_start include/trace/events/timer.h:53 [inline]
enqueue_timer+0x440/0x600 kernel/time/timer.c:609
__mod_timer+0x92b/0xee0
mrp_join_timer_arm net/802/mrp.c:596 [inline]
mrp_join_timer+0x144/0x180 net/802/mrp.c:611
call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504
expire_timers kernel/time/timer.c:1549 [inline]
__run_timers+0x67c/0x890 kernel/time/timer.c:1820
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
handle_softirqs+0x2ee/0xa40 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0x157/0x240 kernel/softirq.c:661
irq_exit_rcu+0x5/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 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+0x0/0x80
__sock_create+0xd1/0x930 net/socket.c:1506
sock_create net/socket.c:1606 [inline]
__sys_socketpair+0x2c1/0x700 net/socket.c:1733
__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(&base->lock);
lock(krc.lock);
lock(&base->lock);
lock(krc.lock);
*** DEADLOCK ***
4 locks held by syz.0.12945/9957:
#0: ffffc900001e0bc0 ((&app->join_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc2/0x6b0 kernel/time/timer.c:1501
#1: ffff888059d9bcc8 (&app->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#1: ffff888059d9bcc8 (&app->lock){+.-.}-{2:2}, at: mrp_join_timer+0xca/0x180 net/802/mrp.c:609
#2: ffff8880b8f28358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999
#3: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#3: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#3: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2283 [inline]
#3: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x146/0x440 kernel/trace/bpf_trace.c:2324
stack backtrace:
CPU: 1 PID: 9957 Comm: syz.0.12945 Not tainted 6.1.128-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_run3+0x231/0x440 kernel/trace/bpf_trace.c:2324
__traceiter_timer_start+0x79/0xd0 include/trace/events/timer.h:53
trace_timer_start include/trace/events/timer.h:53 [inline]
enqueue_timer+0x440/0x600 kernel/time/timer.c:609
__mod_timer+0x92b/0xee0
mrp_join_timer_arm net/802/mrp.c:596 [inline]
mrp_join_timer+0x144/0x180 net/802/mrp.c:611
call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504
expire_timers kernel/time/timer.c:1549 [inline]
__run_timers+0x67c/0x890 kernel/time/timer.c:1820
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
handle_softirqs+0x2ee/0xa40 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0x157/0x240 kernel/softirq.c:661
irq_exit_rcu+0x5/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x80 kernel/kcov.c:314
Code: 39 c8 77 22 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 34 cf 77 7e 65 8b 05 35 cf 77 7e 25 00 01
RSP: 0018:ffffc90003387d80 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000080000
RDX: ffffc9000f6bd000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000000001e R08: ffffffff8404ec78 R09: 0000000000000000
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffffc90003387e60
__sock_create+0xd1/0x930 net/socket.c:1506
sock_create net/socket.c:1606 [inline]
__sys_socketpair+0x2c1/0x700 net/socket.c:1733
__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: 0033:0x7f4a9e98cda9
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:00007f4a9f790038 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007f4a9eba5fa0 RCX: 00007f4a9e98cda9
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 000000000000001e
RBP: 00007f4a9ea0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000180 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f4a9eba5fa0 R15: 00007ffc05f28cf8
----------------
Code disassembly (best guess):
0: 39 c8 cmp %ecx,%eax
2: 77 22 ja 0x26
4: 89 f8 mov %edi,%eax
6: 89 f6 mov %esi,%esi
8: 49 ff c2 inc %r10
b: 4c 89 11 mov %r10,(%rcx)
e: 48 c7 44 0a 08 03 00 movq $0x3,0x8(%rdx,%rcx,1)
15: 00 00
17: 48 89 44 0a 10 mov %rax,0x10(%rdx,%rcx,1)
1c: 48 89 74 0a 18 mov %rsi,0x18(%rdx,%rcx,1)
21: 4c 89 44 0a 20 mov %r8,0x20(%rdx,%rcx,1)
26: c3 ret
27: 0f 1f 00 nopl (%rax)
* 2a: 4c 8b 04 24 mov (%rsp),%r8 <-- trapping instruction
2e: 65 48 8b 15 34 cf 77 mov %gs:0x7e77cf34(%rip),%rdx # 0x7e77cf6a
35: 7e
36: 65 8b 05 35 cf 77 7e mov %gs:0x7e77cf35(%rip),%eax # 0x7e77cf72
3d: 25 .byte 0x25
3e: 00 01 add %al,(%rcx)