Warning: Permanently added '10.128.0.77' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 61.726480][ T6850] ------------[ cut here ]------------ [ 61.732126][ T6850] refcount_t: underflow; use-after-free. [ 61.755537][ T6850] WARNING: CPU: 0 PID: 6850 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 [ 61.832863][ T6850] Kernel panic - not syncing: panic_on_warn set ... [ 61.839495][ T6850] CPU: 0 PID: 6850 Comm: syz-executor115 Not tainted 5.9.0-rc2-syzkaller #0 [ 61.848171][ T6850] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.858231][ T6850] Call Trace: [ 61.861635][ T6850] dump_stack+0x18f/0x20d [ 61.866081][ T6850] panic+0x2e3/0x75c [ 61.869988][ T6850] ? __warn_printk+0xf3/0xf3 [ 61.875146][ T6850] ? __warn.cold+0x5/0x4a [ 61.879664][ T6850] ? __warn+0xd6/0x1f2 [ 61.883756][ T6850] ? refcount_warn_saturate+0x1d1/0x1e0 [ 61.889321][ T6850] __warn.cold+0x20/0x4a [ 61.893577][ T6850] ? refcount_warn_saturate+0x1d1/0x1e0 [ 61.899135][ T6850] report_bug+0x1bd/0x210 [ 61.903479][ T6850] handle_bug+0x38/0x90 [ 61.907644][ T6850] ? __warn_printk+0xc6/0xf3 [ 61.912456][ T6850] exc_invalid_op+0x14/0x40 [ 61.918905][ T6850] asm_exc_invalid_op+0x12/0x20 [ 61.923778][ T6850] RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0 [ 61.929993][ T6850] Code: e9 db fe ff ff 48 89 df e8 dc ee 18 fe e9 8a fe ff ff e8 e2 d5 d8 fd 48 c7 c7 00 db 93 88 c6 05 da e4 11 07 01 e8 d1 e6 a9 fd <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55 [ 61.949616][ T6850] RSP: 0018:ffffc90001fe74a0 EFLAGS: 00010282 [ 61.955690][ T6850] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 61.963797][ T6850] RDX: ffff8880946b4180 RSI: ffffffff815dafc7 RDI: fffff520003fce86 [ 61.972315][ T6850] RBP: 0000000000000003 R08: 0000000000000001 R09: ffff8880ae6318e7 [ 61.980322][ T6850] R10: 0000000000000000 R11: 0000000035383654 R12: ffff8880a0b75864 [ 61.988307][ T6850] R13: 00000000ffffffea R14: ffff88809dc40000 R15: ffff88809fa52024 [ 61.996317][ T6850] ? vprintk_func+0x97/0x1a6 [ 62.000928][ T6850] qdisc_put+0xbe/0xe0 [ 62.005012][ T6850] ? red_offload.isra.0+0x480/0x480 [ 62.011217][ T6850] qdisc_create+0xcd9/0x12e0 [ 62.015813][ T6850] ? tc_get_qdisc+0xad0/0xad0 [ 62.020820][ T6850] ? lock_is_held_type+0xbb/0xf0 [ 62.025926][ T6850] tc_modify_qdisc+0x4c8/0x1990 [ 62.030786][ T6850] ? rtnetlink_rcv_msg+0x3f9/0xad0 [ 62.036032][ T6850] ? qdisc_create+0x12e0/0x12e0 [ 62.041165][ T6850] ? lock_is_held_type+0xbb/0xf0 [ 62.046108][ T6850] ? qdisc_create+0x12e0/0x12e0 [ 62.050962][ T6850] rtnetlink_rcv_msg+0x44e/0xad0 [ 62.056246][ T6850] ? rtnetlink_put_metrics+0x510/0x510 [ 62.062295][ T6850] ? lock_acquire+0x1f1/0xad0 [ 62.066956][ T6850] ? netlink_deliver_tap+0x146/0xb70 [ 62.072241][ T6850] netlink_rcv_skb+0x15a/0x430 [ 62.077015][ T6850] ? rtnetlink_put_metrics+0x510/0x510 [ 62.082472][ T6850] ? netlink_ack+0xa10/0xa10 [ 62.087252][ T6850] ? lock_is_held_type+0xbb/0xf0 [ 62.092273][ T6850] netlink_unicast+0x533/0x7d0 [ 62.097023][ T6850] ? netlink_attachskb+0x810/0x810 [ 62.102132][ T6850] ? _copy_from_iter_full+0x247/0x890 [ 62.107506][ T6850] ? __phys_addr+0x9a/0x110 [ 62.111998][ T6850] ? __phys_addr_symbol+0x2c/0x70 [ 62.117025][ T6850] ? __check_object_size+0x171/0x3e4 [ 62.122404][ T6850] netlink_sendmsg+0x856/0xd90 [ 62.127978][ T6850] ? netlink_unicast+0x7d0/0x7d0 [ 62.132925][ T6850] ? bpf_lsm_socket_sendmsg+0x5/0x10 [ 62.138204][ T6850] ? netlink_unicast+0x7d0/0x7d0 [ 62.143364][ T6850] sock_sendmsg+0xcf/0x120 [ 62.147901][ T6850] ____sys_sendmsg+0x6e8/0x810 [ 62.152657][ T6850] ? kernel_sendmsg+0x50/0x50 [ 62.157319][ T6850] ? do_recvmmsg+0x6d0/0x6d0 [ 62.161893][ T6850] ? mark_lock+0xbc/0x1710 [ 62.166338][ T6850] ? lock_is_held_type+0xbb/0xf0 [ 62.171275][ T6850] ? __lock_acquire+0xbb5/0x5640 [ 62.176266][ T6850] ___sys_sendmsg+0xf3/0x170 [ 62.180879][ T6850] ? sendmsg_copy_msghdr+0x160/0x160 [ 62.186149][ T6850] ? percpu_counter_add_batch+0x126/0x180 [ 62.191886][ T6850] ? lock_acquire+0x1f1/0xad0 [ 62.196896][ T6850] ? __get_unused_fd_flags+0x60/0x60 [ 62.202160][ T6850] ? find_held_lock+0x2d/0x110 [ 62.206907][ T6850] ? __fd_install+0x1b4/0x600 [ 62.211759][ T6850] ? lock_downgrade+0x830/0x830 [ 62.216622][ T6850] ? __fget_light+0x215/0x280 [ 62.221296][ T6850] __sys_sendmsg+0xe5/0x1b0 [ 62.226044][ T6850] ? __sys_sendmsg_sock+0xb0/0xb0 [ 62.231061][ T6850] ? trace_hardirqs_on+0x5f/0x220 [ 62.236188][ T6850] ? lockdep_hardirqs_on+0x76/0xf0 [ 62.241305][ T6850] do_syscall_64+0x2d/0x70 [ 62.245726][ T6850] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 62.251688][ T6850] RIP: 0033:0x4404a9 [ 62.255583][ T6850] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 62.275289][ T6850] RSP: 002b:00007fff85fa9228 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 62.283692][ T6850] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004404a9 [ 62.291673][ T6850] RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000004 [ 62.299653][ T6850] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 [ 62.307636][ T6850] R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000401cb0 [ 62.315806][ T6850] R13: 0000000000401d40 R14: 0000000000000000 R15: 0000000000000000 [ 62.325594][ T6850] Kernel Offset: disabled [ 62.330015][ T6850] Rebooting in 86400 seconds..