------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 10249 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 1 PID: 10249 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: e0ad77a465337500 RBX: 0000000000000002 RCX: ffff88813fe81dc0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffffc900001e0990 R08: dffffc0000000000 R09: fffff5200003c095 R10: fffff5200003c095 R11: 1ffff9200003c094 R12: ffff8880742b3880 R13: dffffc0000000000 R14: 0000000000000002 R15: ffff888078785448 FS: 0000555583144500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7fee030286 CR3: 0000000065865000 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:___slab_alloc+0x106f/0x1220 mm/slub.c:3258 Code: 48 c7 44 24 70 00 00 00 00 9c 8f 44 24 70 f7 44 24 70 00 02 00 00 75 3a f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 78 0f 85 ac 00 00 00 4c 89 f8 48 81 c4 80 00 00 00 5b RSP: 0018:ffffc9000d696400 EFLAGS: 00000206 RAX: e0ad77a465337500 RBX: ffff8880b8f3e530 RCX: e0ad77a465337500 RDX: dffffc0000000000 RSI: ffffffff8a6bffe0 RDI: ffffffff8abf1360 RBP: 0000000000000246 R08: dffffc0000000000 R09: fffffbfff211704a R10: fffffbfff211704a R11: 1ffffffff2117049 R12: ffff8880b8f3e530 R13: ffff8880b8f3e510 R14: 0000000000000001 R15: ffff88802496ed40 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3437 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] ref_tracker_alloc+0x129/0x450 lib/ref_tracker.c:85 __netdev_tracker_alloc include/linux/netdevice.h:4051 [inline] netdev_hold include/linux/netdevice.h:4080 [inline] fib_check_nh_nongw net/ipv4/fib_semantics.c:1239 [inline] fib_check_nh+0xc33/0x18f0 net/ipv4/fib_semantics.c:1259 fib_create_info+0x1458/0x2490 net/ipv4/fib_semantics.c:1558 fib_table_insert+0xc3/0x1b50 net/ipv4/fib_trie.c:1217 fib_magic+0x2c1/0x390 net/ipv4/fib_frontend.c:1118 fib_add_ifaddr+0x3f7/0x5e0 net/ipv4/fib_frontend.c:1162 fib_netdev_event+0x361/0x470 net/ipv4/fib_frontend.c:1500 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] __dev_notify_flags+0x178/0x2d0 net/core/dev.c:-1 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8702 do_setlink+0xc31/0x3c40 net/core/rtnetlink.c:2833 __rtnl_newlink net/core/rtnetlink.c:3608 [inline] rtnl_newlink+0x17d6/0x1ff0 net/core/rtnetlink.c:3655 rtnetlink_rcv_msg+0x79b/0xed0 net/core/rtnetlink.c:6153 netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2493 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline] netlink_unicast+0x74c/0x8c0 net/netlink/af_netlink.c:1337 netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1859 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] __sys_sendto+0x44f/0x5c0 net/socket.c:2153 __do_sys_sendto net/socket.c:2165 [inline] __se_sys_sendto net/socket.c:2161 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2161 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: 0033:0x7f714bd907bc Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b RSP: 002b:00007ffd7a4c2cb0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f714cae4620 RCX: 00007f714bd907bc RDX: 000000000000002c RSI: 00007f714cae4670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffd7a4c2d04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f714cae4670 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 48 c7 44 24 70 00 00 movq $0x0,0x70(%rsp) 7: 00 00 9: 9c pushf a: 8f 44 24 70 pop 0x70(%rsp) e: f7 44 24 70 00 02 00 testl $0x200,0x70(%rsp) 15: 00 16: 75 3a jne 0x52 18: f7 c5 00 02 00 00 test $0x200,%ebp 1e: 74 01 je 0x21 20: fb sti 21: 65 48 8b 04 25 28 00 mov %gs:0x28,%rax 28: 00 00 * 2a: 48 3b 44 24 78 cmp 0x78(%rsp),%rax <-- trapping instruction 2f: 0f 85 ac 00 00 00 jne 0xe1 35: 4c 89 f8 mov %r15,%rax 38: 48 81 c4 80 00 00 00 add $0x80,%rsp 3f: 5b pop %rbx