------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 0 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.15.185-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 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:ffffc90000007848 EFLAGS: 00010246 RAX: d9a143cc39a94200 RBX: 0000000000000002 RCX: ffffffff8bebc3c0 RDX: 0000000000000100 RSI: 0000000000000101 RDI: 0000000000000000 RBP: ffffc900000079b0 R08: dffffc0000000000 R09: fffff52000000e6d R10: fffff52000000e6d R11: 1ffff92000000e6c R12: ffff888079788000 R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9a0f186eb0 CR3: 000000005d305000 CR4: 00000000003506f0 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:default_idle+0xb/0x10 arch/x86/kernel/process.c:723 Code: bf 48 89 df e8 26 8c 12 f8 eb b5 e8 3f be f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 97 13 5b 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 vkms_vblank_simulate: vblank timer overrun RSP: 0018:ffffffff8be07dc8 EFLAGS: 000002c6 RAX: d9a143cc39a94200 RBX: ffffffff8bebc3c0 RCX: d9a143cc39a94200 RDX: 0000000000000001 RSI: ffffffff8a0b11c0 RDI: ffffffff8a59a740 RBP: ffffffff8be07ef8 R08: dffffc0000000000 R09: ffffed101720765a R10: ffffed101720765a R11: 1ffff11017207659 R12: ffffffff8d68abe8 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff17d7878 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x21b/0x5b0 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_kernel+0x486/0x530 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb ---------------- Code disassembly (best guess): 0: bf 48 89 df e8 mov $0xe8df8948,%edi 5: 26 8c 12 es mov %ss,(%rdx) 8: f8 clc 9: eb b5 jmp 0xffffffc0 b: e8 3f be f6 ff call 0xfff6be4f 10: 00 00 add %al,(%rax) 12: cc int3 13: cc int3 14: 00 00 add %al,(%rax) 16: cc int3 17: cc int3 18: 00 00 add %al,(%rax) 1a: cc int3 1b: cc int3 1c: 00 00 add %al,(%rax) 1e: cc int3 1f: 66 90 xchg %ax,%ax 21: 0f 00 2d 97 13 5b 00 verw 0x5b1397(%rip) # 0x5b13bf 28: fb sti 29: f4 hlt * 2a: c3 ret <-- trapping instruction 2b: 0f 1f 40 00 nopl 0x0(%rax) 2f: 41 57 push %r15 31: 41 56 push %r14 33: 53 push %rbx 34: 49 be 00 00 00 00 00 movabs $0xdffffc0000000000,%r14 3b: fc ff df 3e: 65 gs 3f: 48 rex.W