------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 5115 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 1 PID: 5115 Comm: kworker/1:17 Not tainted 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events_power_efficient gc_worker RIP: 0010:refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25 Code: 09 01 48 c7 c7 40 6b 59 8a e8 dd 27 bb 05 0f 0b eb e0 e8 04 42 9c fd c6 05 ae 8f 79 09 01 48 c7 c7 80 6a 59 8a e8 c1 27 bb 05 <0f> 0b eb c4 e8 e8 41 9c fd c6 05 93 8f 79 09 01 48 c7 c7 e0 6a 59 RSP: 0018:ffffc90000dd0848 EFLAGS: 00010246 RAX: 41950a7d80172400 RBX: 0000000000000002 RCX: ffff8880294a1dc0 RDX: 0000000000000100 RSI: 0000000000000100 RDI: 0000000000000000 RBP: ffffc90000dd09b0 R08: dffffc0000000000 R09: fffff520001ba06d R10: fffff520001ba06d R11: 1ffff920001ba06c R12: ffff888078d68000 R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1aead4cf98 CR3: 00000000454a9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:-1 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] get_net include/net/net_namespace.h:252 [inline] tipc_aead_encrypt net/tipc/crypto.c:832 [inline] tipc_crypto_xmit+0x1949/0x2560 net/tipc/crypto.c:1772 tipc_bearer_xmit_skb+0x228/0x3c0 net/tipc/bearer.c:574 tipc_disc_timeout+0x568/0x6b0 net/tipc/discover.c:338 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x525/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627 Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b RSP: 0018:ffffc900032af9a0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 41950a7d80172400 RDX: 0000000000000000 RSI: ffffffff8a0b2460 RDI: ffffffff8a59a740 RBP: ffffc900032afac0 R08: dffffc0000000000 R09: fffffbfff1ff3619 R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: ffffffff8c11bfa0 R13: 1ffff92000655f40 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] gc_worker+0x25c/0x13a0 net/netfilter/nf_conntrack_core.c:1470 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 ---------------- Code disassembly (best guess): 0: 00 9c 8f 84 24 80 00 add %bl,0x802484(%rdi,%rcx,4) 7: 00 00 add %al,(%rax) 9: f6 84 24 81 00 00 00 testb $0x2,0x81(%rsp) 10: 02 11: 0f 85 f6 00 00 00 jne 0x10d 17: 41 f7 c6 00 02 00 00 test $0x200,%r14d 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 60 0e 36 movq $0x45e0360e,0x60(%rsp) 28: e0 45 * 2a: 4b c7 44 3d 00 00 00 movq $0x0,0x0(%r13,%r15,1) <-- trapping instruction 31: 00 00 33: 66 43 c7 44 3d 09 00 movw $0x0,0x9(%r13,%r15,1) 3a: 00 3b: 43 rex.XB 3c: c6 .byte 0xc6 3d: 44 rex.R 3e: 3d .byte 0x3d 3f: 0b .byte 0xb