------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 2 PID: 12615 at lib/refcount.c:25 refcount_warn_saturate+0x1ca/0x210 lib/refcount.c:25 Modules linked in: CPU: 2 UID: 0 PID: 12615 Comm: syz-executor Not tainted 6.15.0-syzkaller-12141-gec7714e49479 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:refcount_warn_saturate+0x1ca/0x210 lib/refcount.c:25 Code: ff 89 de e8 98 4d e0 fc 84 db 0f 85 e6 fe ff ff e8 ab 52 e0 fc c6 05 d6 9e b4 0b 01 90 48 c7 c7 80 1b 15 8c e8 17 1e 9f fc 90 <0f> 0b 90 90 e9 c3 fe ff ff e8 88 52 e0 fc c6 05 b1 9e b4 0b 01 90 RSP: 0018:ffffc900006488b0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817ae368 RDX: ffff888029e3a440 RSI: ffffffff817ae375 RDI: 0000000000000001 RBP: ffff88802c6f426c R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88802c6f426c R13: ffff88802c6f4100 R14: ffff888025c0de00 R15: ffff88803bd29000 FS: 000055558a149500(0000) GS:ffff8880d695a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1bdc9726e0 CR3: 000000003ba8a000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:289 [inline] __refcount_inc include/linux/refcount.h:366 [inline] refcount_inc include/linux/refcount.h:383 [inline] get_net include/net/net_namespace.h:268 [inline] tipc_aead_encrypt net/tipc/crypto.c:821 [inline] tipc_crypto_xmit+0x20c1/0x2550 net/tipc/crypto.c:1761 tipc_bearer_xmit_skb+0x15f/0x430 net/tipc/bearer.c:572 tipc_disc_timeout+0x5b2/0x850 net/tipc/discover.c:338 call_timer_fn+0x19a/0x620 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers+0x6ef/0x960 kernel/time/timer.c:2372 __run_timer_base kernel/time/timer.c:2384 [inline] __run_timer_base kernel/time/timer.c:2376 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2393 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2403 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:insert_entry fs/proc/proc_sysctl.c:154 [inline] RIP: 0010:insert_header+0x3c7/0x1480 fs/proc/proc_sysctl.c:252 Code: 00 e8 ed f6 5b ff 48 89 d8 48 c1 e8 03 80 3c 28 00 0f 85 ae 0c 00 00 48 8b 1b 48 83 c3 08 e8 d0 f6 5b ff 48 89 d8 48 c1 e8 03 <80> 3c 28 00 0f 85 84 0c 00 00 48 8b 03 48 85 c0 0f 84 04 08 00 00 RSP: 0018:ffffc9000691ee40 EFLAGS: 00000a02 RAX: 1ffff11006bff415 RBX: ffff888035ffa0a8 RCX: ffffffff8260203d RDX: ffff888029e3a440 RSI: ffffffff82601f80 RDI: 0000000000000005 RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 00000000ffffffed R11: 0000000000000001 R12: 00000000ffffffed R13: ffff888035ffa098 R14: 000000000000000d R15: ffffffff8cf35300 __register_sysctl_table+0x70a/0x1900 fs/proc/proc_sysctl.c:1396 __addrconf_sysctl_register+0x1a2/0x360 net/ipv6/addrconf.c:7248 addrconf_sysctl_register net/ipv6/addrconf.c:7296 [inline] addrconf_sysctl_register+0x15f/0x1f0 net/ipv6/addrconf.c:7285 ipv6_add_dev+0xb39/0x15f0 net/ipv6/addrconf.c:458 addrconf_notify+0x53e/0x19e0 net/ipv6/addrconf.c:3654 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] register_netdevice+0x182e/0x2270 net/core/dev.c:11142 veth_newlink+0x446/0xa00 drivers/net/veth.c:1884 rtnl_newlink_create net/core/rtnetlink.c:3823 [inline] __rtnl_newlink net/core/rtnetlink.c:3940 [inline] rtnl_newlink+0xc45/0x2000 net/core/rtnetlink.c:4055 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] __sys_sendto+0x4a3/0x520 net/socket.c:2180 __do_sys_sendto net/socket.c:2187 [inline] __se_sys_sendto net/socket.c:2183 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2183 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1349f907bc 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:00007ffc374220a0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f134ace4620 RCX: 00007f1349f907bc RDX: 0000000000000064 RSI: 00007f134ace4670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffc374220f4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f134ace4670 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 00 e8 add %ch,%al 2: ed in (%dx),%eax 3: f6 5b ff negb -0x1(%rbx) 6: 48 89 d8 mov %rbx,%rax 9: 48 c1 e8 03 shr $0x3,%rax d: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) 11: 0f 85 ae 0c 00 00 jne 0xcc5 17: 48 8b 1b mov (%rbx),%rbx 1a: 48 83 c3 08 add $0x8,%rbx 1e: e8 d0 f6 5b ff call 0xff5bf6f3 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) <-- trapping instruction 2e: 0f 85 84 0c 00 00 jne 0xcb8 34: 48 8b 03 mov (%rbx),%rax 37: 48 85 c0 test %rax,%rax 3a: 0f 84 04 08 00 00 je 0x844