------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 15761 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 1 PID: 15761 Comm: syz.3.3083 Not tainted 6.1.141-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25 Code: 09 01 48 c7 c7 a0 d2 be 8a e8 ad 30 45 fd 0f 0b eb e0 e8 f4 1d 79 fd c6 05 fa 72 e2 09 01 48 c7 c7 e0 d1 be 8a e8 91 30 45 fd <0f> 0b eb c4 e8 d8 1d 79 fd c6 05 df 72 e2 09 01 48 c7 c7 40 d2 be RSP: 0000:ffffc900001e0688 EFLAGS: 00010246 RAX: 220003a6b81d3f00 RBX: 0000000000000002 RCX: ffff88802ee40000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffffc900001e07e8 R08: dffffc0000000000 R09: fffff5200003c061 R10: fffff5200003c061 R11: 1ffff9200003c060 R12: ffff8880715a9c40 R13: dffffc0000000000 R14: 0000000000000002 R15: ffff888058207c48 FS: 000055555dcd1500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f83f7da45d8 CR3: 000000007d7a8000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000097 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:257 [inline] tipc_aead_encrypt net/tipc/crypto.c:821 [inline] tipc_crypto_xmit+0x17a9/0x2300 net/tipc/crypto.c:1761 tipc_crypto_clone_msg+0x91/0x160 net/tipc/crypto.c:1656 tipc_crypto_xmit+0x1928/0x2300 net/tipc/crypto.c:1717 tipc_bearer_xmit_skb+0x242/0x3f0 net/tipc/bearer.c:574 tipc_disc_timeout+0x568/0x6b0 net/tipc/discover.c:338 call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x525/0x7c0 kernel/time/timer.c:1820 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 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:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5123 Code: 0f 84 3b 01 00 00 48 85 db 0f 85 5a 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 f0 27 c1 08 e8 7b c0 2e 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0000:ffffc9000396fcd8 EFLAGS: 00000286 RAX: 220003a6b81d3f00 RBX: 0000000000000000 RCX: 220003a6b81d3f00 RDX: dffffc0000000000 RSI: ffffffff8a6bffe0 RDI: ffffffff8abf1360 RBP: ffffc9000396fd30 R08: dffffc0000000000 R09: ffffed10171e7551 R10: ffffed10171e7551 R11: 1ffff110171e7550 R12: ffff88802ee40000 R13: dffffc0000000000 R14: ffff88813fe13b80 R15: ffff8880b8f3b550 context_switch kernel/sched/core.c:5247 [inline] __schedule+0x10f1/0x40d0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 exit_to_user_mode_loop+0x47/0x110 kernel/entry/common.c:165 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 RIP: 0033:0x7f9b6886e95b Code: 03 14 ca 80 3d 6d 92 34 00 00 49 89 d6 48 89 d5 74 28 25 ff 0f 00 00 83 f0 3d 8d 04 c0 89 c5 c1 ed 04 31 c5 69 ed 2d eb d4 27 <89> e8 c1 e8 0f 31 c5 81 e5 ff 0f 00 00 48 31 d5 80 3d d6 36 34 00 RSP: 002b:00007fff0ff64ac0 EFLAGS: 00000a83 RAX: 0000000000007a07 RBX: 00007f9b696e5720 RCX: 00000000000078b2 RDX: ffffffff8183db9a RSI: ffffffff8183dbf7 RDI: 0000000000000009 RBP: 00000000f2ba635b R08: 00007f9b68bb6038 R09: 00007f9b68ba2000 R10: 00007f9b67dff008 R11: 0000000000000009 R12: 0000000000000009 R13: 0000000000000000 R14: ffffffff8183db9a R15: 00000000000078b2 ---------------- Code disassembly (best guess): 0: 0f 84 3b 01 00 00 je 0x141 6: 48 85 db test %rbx,%rbx 9: 0f 85 5a 01 00 00 jne 0x169 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 f0 27 c1 08 call 0x8c12810 20: e8 7b c0 2e 00 call 0x2ec0a0 25: fb sti 26: 4c 8b 65 c0 mov -0x40(%rbp),%r12 * 2a: 49 8d bc 24 f8 15 00 lea 0x15f8(%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