======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc6-syzkaller-00169-g906bd684e4b1 #0 Not tainted
------------------------------------------------------
syz.3.2753/16124 is trying to acquire lock:
ffff8880b8629598 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:3312 [inline]
ffff8880b8629598 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3725 [inline]
ffff8880b8629598 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0xda/0xbe0 kernel/rcu/tree.c:3811
but task is already holding lock:
ffff8880b862a858 (&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:2523
queue_delayed_work_on+0x12a/0x150 kernel/workqueue.c:2552
kvfree_call_rcu+0x749/0xbe0 kernel/rcu/tree.c:3839
pwq_release_workfn+0x4dd/0xa50 kernel/workqueue.c:5078
kthread_worker_fn+0x305/0xba0 kernel/kthread.c:844
kthread+0x2c1/0x3a0 kernel/kthread.c:389
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:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
__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:3312 [inline]
add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3725 [inline]
kvfree_call_rcu+0xda/0xbe0 kernel/rcu/tree.c:3811
trie_delete_elem+0x5c5/0x820 kernel/bpf/lpm_trie.c:540
bpf_prog_2e5e7763945ac34e+0x45/0x49
bpf_dispatcher_nop_func include/linux/bpf.h:1265 [inline]
__bpf_prog_run include/linux/filter.h:701 [inline]
bpf_prog_run include/linux/filter.h:708 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2316 [inline]
bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2357
__bpf_trace_timer_start+0xc7/0x100 include/trace/events/timer.h:52
__traceiter_timer_start+0x64/0xb0 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
internal_add_timer kernel/time/timer.c:688 [inline]
__mod_timer+0x8d7/0xdc0 kernel/time/timer.c:1183
add_timer+0x62/0x90 kernel/time/timer.c:1296
dsp_cmx_send+0xc30/0x1760 drivers/isdn/mISDN/dsp_cmx.c:1839
call_timer_fn+0x1a0/0x610 kernel/time/timer.c:1794
expire_timers kernel/time/timer.c:1845 [inline]
__run_timers+0x6e8/0x930 kernel/time/timer.c:2419
__run_timer_base kernel/time/timer.c:2430 [inline]
__run_timer_base kernel/time/timer.c:2423 [inline]
run_timer_base+0x111/0x190 kernel/time/timer.c:2439
run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2449
handle_softirqs+0x213/0x8f0 kernel/softirq.c:554
__do_softirq kernel/softirq.c:588 [inline]
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:637 [inline]
irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
__sanitizer_cov_trace_const_cmp1+0x0/0x20 kernel/kcov.c:294
__unix_dgram_recvmsg+0x4c3/0xe50 net/unix/af_unix.c:2483
unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2537
sock_recvmsg_nosec net/socket.c:1051 [inline]
____sys_recvmsg+0x5f8/0x6b0 net/socket.c:2824
___sys_recvmsg+0x115/0x1a0 net/socket.c:2868
do_recvmmsg+0x2ba/0x750 net/socket.c:2962
__sys_recvmmsg net/socket.c:3041 [inline]
__do_sys_recvmmsg net/socket.c:3064 [inline]
__se_sys_recvmmsg net/socket.c:3057 [inline]
__x64_sys_recvmmsg+0x239/0x290 net/socket.c:3057
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 ***
5 locks held by syz.3.2753/16124:
#0: ffff888055462f10 (&u->iolock){+.+.}-{3:3}, at: __unix_dgram_recvmsg+0x267/0xe50 net/unix/af_unix.c:2432
#1: ffffc90000007cb0 ((&dsp_spl_tl)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x610 kernel/time/timer.c:1791
#2: ffffffff8fac09d8 (dsp_lock){..-.}-{2:2}, at: dsp_cmx_send+0x23/0x1760 drivers/isdn/mISDN/dsp_cmx.c:1632
#3: ffff8880b862a858 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5d/0x220 kernel/time/timer.c:1051
#4: ffffffff8e1b8340 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#4: ffffffff8e1b8340 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#4: ffffffff8e1b8340 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2315 [inline]
#4: ffffffff8e1b8340 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2357
stack backtrace:
CPU: 0 UID: 0 PID: 16124 Comm: syz.3.2753 Not tainted 6.12.0-rc6-syzkaller-00169-g906bd684e4b1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_circular_bug+0x41c/0x610 kernel/locking/lockdep.c:2074
check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
__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:3312 [inline]
add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3725 [inline]
kvfree_call_rcu+0xda/0xbe0 kernel/rcu/tree.c:3811
trie_delete_elem+0x5c5/0x820 kernel/bpf/lpm_trie.c:540
bpf_prog_2e5e7763945ac34e+0x45/0x49
bpf_dispatcher_nop_func include/linux/bpf.h:1265 [inline]
__bpf_prog_run include/linux/filter.h:701 [inline]
bpf_prog_run include/linux/filter.h:708 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2316 [inline]
bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2357
__bpf_trace_timer_start+0xc7/0x100 include/trace/events/timer.h:52
__traceiter_timer_start+0x64/0xb0 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
internal_add_timer kernel/time/timer.c:688 [inline]
__mod_timer+0x8d7/0xdc0 kernel/time/timer.c:1183
add_timer+0x62/0x90 kernel/time/timer.c:1296
dsp_cmx_send+0xc30/0x1760 drivers/isdn/mISDN/dsp_cmx.c:1839
call_timer_fn+0x1a0/0x610 kernel/time/timer.c:1794
expire_timers kernel/time/timer.c:1845 [inline]
__run_timers+0x6e8/0x930 kernel/time/timer.c:2419
__run_timer_base kernel/time/timer.c:2430 [inline]
__run_timer_base kernel/time/timer.c:2423 [inline]
run_timer_base+0x111/0x190 kernel/time/timer.c:2439
run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2449
handle_softirqs+0x213/0x8f0 kernel/softirq.c:554
__do_softirq kernel/softirq.c:588 [inline]
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:637 [inline]
irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x0/0x20 kernel/kcov.c:299
Code: 0c 24 48 89 f2 48 89 fe bf 06 00 00 00 e9 b8 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 e9
RSP: 0000:ffffc90002d87808 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffff88802860a3c0 RCX: ffffffff89c2d102
RDX: 1ffff1100aa8c534 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888055462940 R08: 0000000000000000 R09: ffffed100aa8c534
R10: ffff8880554629a7 R11: 0000000000000001 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888055462ea8
__unix_dgram_recvmsg+0x4c3/0xe50 net/unix/af_unix.c:2483
unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2537
sock_recvmsg_nosec net/socket.c:1051 [inline]
____sys_recvmsg+0x5f8/0x6b0 net/socket.c:2824
___sys_recvmsg+0x115/0x1a0 net/socket.c:2868
do_recvmmsg+0x2ba/0x750 net/socket.c:2962
__sys_recvmmsg net/socket.c:3041 [inline]
__do_sys_recvmmsg net/socket.c:3064 [inline]
__se_sys_recvmmsg net/socket.c:3057 [inline]
__x64_sys_recvmmsg+0x239/0x290 net/socket.c:3057
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: 0033:0x7fde4737e719
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:00007fde4812b038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fde47536058 RCX: 00007fde4737e719
RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00007fde473f139e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fde47536058 R15: 00007ffe26a63238
----------------
Code disassembly (best guess):
0: 0c 24 or $0x24,%al
2: 48 89 f2 mov %rsi,%rdx
5: 48 89 fe mov %rdi,%rsi
8: bf 06 00 00 00 mov $0x6,%edi
d: e9 b8 fe ff ff jmp 0xfffffeca
12: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1)
19: 00
1a: 90 nop
1b: 90 nop
1c: 90 nop
1d: 90 nop
1e: 90 nop
1f: 90 nop
20: 90 nop
21: 90 nop
22: 90 nop
23: 90 nop
24: 90 nop
25: 90 nop
26: 90 nop
27: 90 nop
28: 90 nop
29: 90 nop
* 2a: f3 0f 1e fa endbr64 <-- trapping instruction
2e: 48 8b 0c 24 mov (%rsp),%rcx
32: 40 0f b6 d6 movzbl %sil,%edx
36: 40 0f b6 f7 movzbl %dil,%esi
3a: bf 01 00 00 00 mov $0x1,%edi
3f: e9 .byte 0xe9