------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 59 at lib/refcount.c:25 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25
Modules linked in:
CPU: 0 UID: 0 PID: 59 Comm: kworker/u8:4 Not tainted 6.15.0-syzkaller-11802-g1af80d00e1e0 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: netns cleanup_net
RIP: 0010:refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25
Code: 00 00 e8 a9 76 00 fd 5b 41 5e e9 3c 5b 50 fc cc e8 9b 76 00 fd c6 05 9a 09 cb 0a 01 90 48 c7 c7 c0 27 e2 8b e8 37 24 c4 fc 90 <0f> 0b 90 90 eb d7 e8 7b 76 00 fd c6 05 7b 09 cb 0a 01 90 48 c7 c7
RSP: 0018:ffffc90000007828 EFLAGS: 00010246
RAX: d3c63ba06e2e0e00 RBX: 0000000000000002 RCX: ffff8880212a5a00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc900000079b0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfaa44 R12: ffff888077458000
R13: dffffc0000000000 R14: ffff88807745816c R15: ffff888055efcc00
FS: 0000000000000000(0000) GS:ffff888125c5c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f07e5a80fe0 CR3: 0000000075612000 CR4: 0000000000350ef0
Call Trace:
__refcount_add include/linux/refcount.h:-1 [inline]
__refcount_inc include/linux/refcount.h:366 [inline]
refcount_inc include/linux/refcount.h:383 [inline]
get_net include/net/net_namespace.h:268 [inline]
tipc_aead_encrypt net/tipc/crypto.c:821 [inline]
tipc_crypto_xmit+0x1820/0x22c0 net/tipc/crypto.c:1761
tipc_bearer_xmit_skb+0x245/0x400 net/tipc/bearer.c:572
tipc_disc_timeout+0x580/0x6d0 net/tipc/discover.c:338
call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
handle_softirqs+0x286/0x870 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5264
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 1f 4c d5 09 e8 3a f9 35 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc9000210e638 EFLAGS: 00000282
RAX: d3c63ba06e2e0e00 RBX: 0000000000000000 RCX: d3c63ba06e2e0e00
RDX: 0000000000000006 RSI: ffffffff8d979f2e RDI: ffffffff8be27240
RBP: ffffc9000210e690 R08: ffffffff8fa0f5f7 R09: 1ffffffff1f41ebe
R10: dffffc0000000000 R11: fffffbfff1f41ebf R12: ffff8880212a5a00
R13: dffffc0000000000 R14: ffff88802f0d1e00 R15: ffff8880b863c4d8
context_switch kernel/sched/core.c:5399 [inline]
__schedule+0x16fd/0x4d00 kernel/sched/core.c:6785
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108
irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 1b 0a fe 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000210ea38 EFLAGS: 00000206
RAX: d3c63ba06e2e0e00 RBX: 0000000000000000 RCX: d3c63ba06e2e0e00
RDX: 0000000000000000 RSI: ffffffff8db66a62 RDI: ffffffff8be27240
RBP: ffffffff81729e15 R08: 0000000000000000 R09: ffffffff81729e15
R10: dffffc0000000000 R11: ffffffff81acf710 R12: 0000000000000002
R13: ffffffff8e13f060 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
__call_rcu_common kernel/rcu/tree.c:3090 [inline]
call_rcu+0x142/0x990 kernel/rcu/tree.c:3210
kernfs_put+0x19e/0x480 fs/kernfs/dir.c:591
kernfs_remove_by_name_ns+0xb7/0x130 fs/kernfs/dir.c:1718
kernfs_remove_by_name include/linux/kernfs.h:633 [inline]
remove_files fs/sysfs/group.c:28 [inline]
sysfs_remove_group+0xfc/0x2c0 fs/sysfs/group.c:322
sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:346
device_remove_groups drivers/base/core.c:2846 [inline]
device_remove_attrs+0x1aa/0x260 drivers/base/core.c:2976
device_del+0x509/0x8e0 drivers/base/core.c:3880
unregister_netdevice_many_notify+0x1d52/0x2320 net/core/dev.c:12111
unregister_netdevice_many net/core/dev.c:12139 [inline]
unregister_netdevice_queue+0x33c/0x380 net/core/dev.c:11983
unregister_netdevice include/linux/netdevice.h:3379 [inline]
nsim_destroy+0x1f6/0x670 drivers/net/netdevsim/netdev.c:1068
__nsim_dev_port_del+0x14d/0x1b0 drivers/net/netdevsim/dev.c:1428
nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline]
nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1661
nsim_dev_reload_down+0x8a/0xc0 drivers/net/netdevsim/dev.c:968
devlink_reload+0x1b6/0x8d0 net/devlink/dev.c:461
devlink_pernet_pre_exit+0x1d9/0x3d0 net/devlink/core.c:509
ops_pre_exit_list net/core/net_namespace.c:162 [inline]
ops_undo_list+0x187/0x990 net/core/net_namespace.c:235
cleanup_net+0x4c5/0x800 net/core/net_namespace.c:686
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
----------------
Code disassembly (best guess):
0: 0f 84 3c 01 00 00 je 0x142
6: 48 85 db test %rbx,%rbx
9: 0f 85 63 01 00 00 jne 0x172
f: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
14: 4c 8b 75 d0 mov -0x30(%rbp),%r14
18: 4c 89 e7 mov %r12,%rdi
1b: e8 1f 4c d5 09 call 0x9d54c3f
20: e8 3a f9 35 00 call 0x35f95f
25: fb sti
26: 4c 8b 65 c0 mov -0x40(%rbp),%r12
* 2a: 49 8d bc 24 18 16 00 lea 0x1618(%r12),%rdi <-- trapping instruction
31: 00
32: 48 89 f8 mov %rdi,%rax
35: 48 c1 e8 03 shr $0x3,%rax
39: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax
3e: 84 c0 test %al,%al