======================================================
WARNING: possible circular locking dependency detected
6.6.94-syzkaller #0 Not tainted
------------------------------------------------------
udevd/5767 is trying to acquire lock:
ffff8880b8f295a8 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2955 [inline]
ffff8880b8f295a8 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3364 [inline]
ffff8880b8f295a8 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x15a/0x780 kernel/rcu/tree.c:3449
but task is already holding lock:
ffff8880b8f297d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 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}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
lock_timer_base+0x123/0x270 kernel/time/timer.c:999
__mod_timer+0xf9/0xdb0 kernel/time/timer.c:1080
queue_delayed_work_on+0x12a/0x1e0 kernel/workqueue.c:1987
kvfree_call_rcu+0x541/0x780 kernel/rcu/tree.c:3477
rtnl_register_internal+0x486/0x590 net/core/rtnetlink.c:264
rtnl_register+0x32/0x70 net/core/rtnetlink.c:314
ip_rt_init+0x2ec/0x390 net/ipv4/route.c:3789
ip_init+0xe/0x20 net/ipv4/ip_output.c:1663
inet_init+0x2c1/0x3e0 net/ipv4/af_inet.c:2024
do_one_initcall+0x1fd/0x750 init/main.c:1238
do_initcall_level+0x137/0x1f0 init/main.c:1300
do_initcalls+0x69/0xd0 init/main.c:1316
kernel_init_freeable+0x3d2/0x570 init/main.c:1553
kernel_init+0x1d/0x1c0 init/main.c:1443
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
-> #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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
__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:2955 [inline]
add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3364 [inline]
kvfree_call_rcu+0x15a/0x780 kernel/rcu/tree.c:3449
trie_delete_elem+0x535/0x6a0 kernel/bpf/lpm_trie.c:545
bpf_prog_1db1603a7cfa36fb+0x45/0x49
bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline]
__bpf_prog_run include/linux/filter.h:612 [inline]
bpf_prog_run include/linux/filter.h:619 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline]
bpf_trace_run3+0x1e7/0x400 kernel/trace/bpf_trace.c:2362
__bpf_trace_timer_start+0x14a/0x1b0 include/trace/events/timer.h:53
trace_timer_start include/trace/events/timer.h:53 [inline]
enqueue_timer+0x398/0x530 kernel/time/timer.c:609
internal_add_timer kernel/time/timer.c:634 [inline]
__mod_timer+0x977/0xdb0 kernel/time/timer.c:1131
dsp_cmx_send+0x1ab8/0x1b40 drivers/isdn/mISDN/dsp_cmx.c:1839
call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
expire_timers kernel/time/timer.c:1751 [inline]
__run_timers+0x52d/0x7d0 kernel/time/timer.c:2022
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xa9/0x110 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
unlock_page_lruvec_irqrestore include/linux/memcontrol.h:1618 [inline]
folio_lruvec_relock_irqsave include/linux/memcontrol.h:1651 [inline]
folio_batch_move_lru+0x2cb/0x6b0 mm/swap.c:208
lru_add_drain_cpu+0x10e/0x8c0 mm/swap.c:644
lru_add_drain+0x121/0x3e0 mm/swap.c:744
__folio_batch_release+0x48/0xe0 mm/swap.c:1039
folio_batch_release include/linux/pagevec.h:83 [inline]
shmem_undo_range+0x5d0/0x1a40 mm/shmem.c:1027
shmem_truncate_range mm/shmem.c:1136 [inline]
shmem_evict_inode+0x273/0xa70 mm/shmem.c:1265
evict+0x486/0x870 fs/inode.c:705
__dentry_kill+0x431/0x650 fs/dcache.c:611
dentry_kill+0xb8/0x290 fs/dcache.c:-1
dput+0xfe/0x1e0 fs/dcache.c:918
do_renameat2+0x8b1/0xc70 fs/namei.c:5027
__do_sys_rename fs/namei.c:5071 [inline]
__se_sys_rename fs/namei.c:5069 [inline]
__x64_sys_rename+0x86/0x90 fs/namei.c:5069
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 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 ***
7 locks held by udevd/5767:
#0: ffff88807e50a418 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:403
#1: ffff88807e6f3f80 (&type->i_mutex_dir_key#5/1){+.+.}-{3:3}, at: lock_rename include/linux/fs.h:-1 [inline]
#1: ffff88807e6f3f80 (&type->i_mutex_dir_key#5/1){+.+.}-{3:3}, at: do_renameat2+0x427/0xc70 fs/namei.c:4964
#2: ffff8880b8f36e18 (lock#4){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
#2: ffff8880b8f36e18 (lock#4){+.+.}-{2:2}, at: lru_add_drain+0x79/0x3e0 mm/swap.c:743
#3: ffffc900001f0c00 ((&dsp_spl_tl)){+.-.}-{0:0}, at: call_timer_fn+0xbf/0x530 kernel/time/timer.c:1697
#4: ffffffff8dd22d18 (dsp_lock){..-.}-{2:2}, at: dsp_cmx_send+0x26/0x1b40 drivers/isdn/mISDN/dsp_cmx.c:1632
#5: ffff8880b8f297d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999
#6: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#6: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#6: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline]
#6: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0xf4/0x400 kernel/trace/bpf_trace.c:2362
stack backtrace:
CPU: 1 PID: 5767 Comm: udevd Not tainted 6.6.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
check_noncircular+0x2bd/0x3c0 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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
__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:2955 [inline]
add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3364 [inline]
kvfree_call_rcu+0x15a/0x780 kernel/rcu/tree.c:3449
trie_delete_elem+0x535/0x6a0 kernel/bpf/lpm_trie.c:545
bpf_prog_1db1603a7cfa36fb+0x45/0x49
bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline]
__bpf_prog_run include/linux/filter.h:612 [inline]
bpf_prog_run include/linux/filter.h:619 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline]
bpf_trace_run3+0x1e7/0x400 kernel/trace/bpf_trace.c:2362
__bpf_trace_timer_start+0x14a/0x1b0 include/trace/events/timer.h:53
trace_timer_start include/trace/events/timer.h:53 [inline]
enqueue_timer+0x398/0x530 kernel/time/timer.c:609
internal_add_timer kernel/time/timer.c:634 [inline]
__mod_timer+0x977/0xdb0 kernel/time/timer.c:1131
dsp_cmx_send+0x1ab8/0x1b40 drivers/isdn/mISDN/dsp_cmx.c:1839
call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
expire_timers kernel/time/timer.c:1751 [inline]
__run_timers+0x52d/0x7d0 kernel/time/timer.c:2022
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa9/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 7a 26 1c f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 82 91 eb f6 65 8b 05 93 e7 93 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9000491f4a0 EFLAGS: 00000206
RAX: 48a6da1b17654600 RBX: 0000000000000a02 RCX: 48a6da1b17654600
RDX: dffffc0000000000 RSI: ffffffff8aaab2c0 RDI: 0000000000000001
RBP: ffffc9000491f530 R08: ffffffff90d85567 R09: 1ffffffff21b0aac
R10: dffffc0000000000 R11: fffffbfff21b0aad R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88801c770050 R15: 1ffff92000923e94
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
unlock_page_lruvec_irqrestore include/linux/memcontrol.h:1618 [inline]
folio_lruvec_relock_irqsave include/linux/memcontrol.h:1651 [inline]
folio_batch_move_lru+0x2cb/0x6b0 mm/swap.c:208
lru_add_drain_cpu+0x10e/0x8c0 mm/swap.c:644
lru_add_drain+0x121/0x3e0 mm/swap.c:744
__folio_batch_release+0x48/0xe0 mm/swap.c:1039
folio_batch_release include/linux/pagevec.h:83 [inline]
shmem_undo_range+0x5d0/0x1a40 mm/shmem.c:1027
shmem_truncate_range mm/shmem.c:1136 [inline]
shmem_evict_inode+0x273/0xa70 mm/shmem.c:1265
evict+0x486/0x870 fs/inode.c:705
__dentry_kill+0x431/0x650 fs/dcache.c:611
dentry_kill+0xb8/0x290 fs/dcache.c:-1
dput+0xfe/0x1e0 fs/dcache.c:918
do_renameat2+0x8b1/0xc70 fs/namei.c:5027
__do_sys_rename fs/namei.c:5071 [inline]
__se_sys_rename fs/namei.c:5069 [inline]
__x64_sys_rename+0x86/0x90 fs/namei.c:5069
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbb3827acc7
Code: e8 5e a7 09 00 f7 d8 19 c0 5b c3 0f 1f 84 00 00 00 00 00 b8 ff ff ff ff 5b c3 66 0f 1f 84 00 00 00 00 00 b8 52 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 01 61 17 00 f7 d8 64 89 02 b8
RSP: 002b:00007ffdeda83878 EFLAGS: 00000206 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 000055f82bf027a0 RCX: 00007fbb3827acc7
RDX: 000055f82bede010 RSI: 00007ffdeda83890 RDI: 00007ffdeda83c90
RBP: 000055f82bf84760 R08: 00000000000001e0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffdeda83890
R13: 00007ffdeda83c90 R14: 0000000000000000 R15: 000055f7ee7ff9dd
----------------
Code disassembly (best guess):
0: 74 05 je 0x7
2: e8 7a 26 1c f7 call 0xf71c2681
7: 48 c7 44 24 20 00 00 movq $0x0,0x20(%rsp)
e: 00 00
10: 9c pushf
11: 8f 44 24 20 pop 0x20(%rsp)
15: f6 44 24 21 02 testb $0x2,0x21(%rsp)
1a: 75 4b jne 0x67
1c: f7 c3 00 02 00 00 test $0x200,%ebx
22: 74 01 je 0x25
24: fb sti
25: bf 01 00 00 00 mov $0x1,%edi
* 2a: e8 82 91 eb f6 call 0xf6eb91b1 <-- trapping instruction
2f: 65 8b 05 93 e7 93 75 mov %gs:0x7593e793(%rip),%eax # 0x7593e7c9
36: 85 c0 test %eax,%eax
38: 74 3c je 0x76
3a: 48 rex.W
3b: c7 .byte 0xc7
3c: 04 24 add $0x24,%al
3e: 0e (bad)
3f: 36 ss