------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 10425 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 1 PID: 10425 Comm: syz-executor 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: 0018:ffffc900001e0828 EFLAGS: 00010246 RAX: 946eb90c1b597600 RBX: 0000000000000002 RCX: ffff88802e641dc0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffffc900001e0990 R08: dffffc0000000000 R09: fffff5200003c095 R10: fffff5200003c095 R11: 1ffff9200003c094 R12: ffff888076429c40 R13: dffffc0000000000 R14: 0000000000000002 R15: ffff88814cd4dc48 FS: 0000555594ad3500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffd88f0000 CR3: 0000000055386000 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:257 [inline] tipc_aead_encrypt net/tipc/crypto.c:821 [inline] tipc_crypto_xmit+0x17a9/0x2300 net/tipc/crypto.c:1761 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194 Code: 74 05 e8 ce 97 6d f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 c6 13 3e f7 65 8b 05 97 d4 e8 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc9000430f500 EFLAGS: 00000206 RAX: 946eb90c1b597600 RBX: 0000000000000a06 RCX: 946eb90c1b597600 RDX: dffffc0000000000 RSI: ffffffff8a6bffe0 RDI: 0000000000000001 RBP: ffffc9000430f580 R08: dffffc0000000000 R09: fffffbfff2117059 R10: fffffbfff2117059 R11: 1ffffffff2117058 R12: dffffc0000000000 R13: ffff888029010000 R14: ffffffff96cd3c90 R15: 1ffff92000861ea0 __debug_check_no_obj_freed lib/debugobjects.c:988 [inline] debug_check_no_obj_freed+0x515/0x530 lib/debugobjects.c:1009 free_pages_prepare mm/page_alloc.c:1465 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x2a6/0x9a0 mm/page_alloc.c:3384 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479 free_slab mm/slub.c:2031 [inline] discard_slab mm/slub.c:2037 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2586 put_cpu_partial+0x17c/0x250 mm/slub.c:2662 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] __kmem_cache_alloc_node+0x140/0x260 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc+0xa0/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] xt_jumpstack_alloc net/netfilter/x_tables.c:1334 [inline] xt_replace_table+0x8e/0x790 net/netfilter/x_tables.c:1393 __do_replace+0x15a/0xa90 net/ipv4/netfilter/arp_tables.c:912 do_replace net/ipv4/netfilter/arp_tables.c:989 [inline] do_arpt_set_ctl+0xa1f/0xef0 net/ipv4/netfilter/arp_tables.c:1429 nf_setsockopt+0x25f/0x280 net/netfilter/nf_sockopt.c:101 __sys_setsockopt+0x3d6/0x660 net/socket.c:2288 __do_sys_setsockopt net/socket.c:2299 [inline] __se_sys_setsockopt net/socket.c:2296 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2296 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3a0af9081a Code: ff ff ff c3 0f 1f 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 49 89 ca b8 36 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7 RSP: 002b:00007ffde3bfbf08 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f3a0af9081a RDX: 0000000000000060 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007ffde3bfbf70 R08: 0000000000000408 R09: 00007ffde3bfc307 R10: 00007f3a0b17f630 R11: 0000000000000246 R12: 00007ffde3bfbf1c R13: 0000555594ae6590 R14: 00000000000c874e R15: 00007ffde3bfc650 ---------------- Code disassembly (best guess): 0: 74 05 je 0x7 2: e8 ce 97 6d f7 call 0xf76d97d5 7: 48 c7 44 24 20 00 00 movq $0x0,0x20(%rsp) e: 00 00 10: 9c pushf 11: 8f 44 24 20 pop 0x20(%rsp) 15: f6 44 24 21 02 testb $0x2,0x21(%rsp) 1a: 75 4b jne 0x67 1c: f7 c3 00 02 00 00 test $0x200,%ebx 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 c6 13 3e f7 call 0xf73e13f5 <-- trapping instruction 2f: 65 8b 05 97 d4 e8 75 mov %gs:0x75e8d497(%rip),%eax # 0x75e8d4cd 36: 85 c0 test %eax,%eax 38: 74 3c je 0x76 3a: 48 rex.W 3b: c7 .byte 0xc7 3c: 04 24 add $0x24,%al 3e: 0e (bad) 3f: 36 ss