[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 55.606747][ T26] audit: type=1800 audit(1569018859.522:25): pid=8632 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 55.648854][ T26] audit: type=1800 audit(1569018859.522:26): pid=8632 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 55.692996][ T26] audit: type=1800 audit(1569018859.522:27): pid=8632 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.10' (ECDSA) to the list of known hosts. syzkaller login: [ 66.802619][ T8785] IPVS: ftp: loaded support on port[0] = 21 [ 66.856074][ T8785] chnl_net:caif_netlink_parms(): no params data found [ 66.884425][ T8785] bridge0: port 1(bridge_slave_0) entered blocking state [ 66.892417][ T8785] bridge0: port 1(bridge_slave_0) entered disabled state [ 66.900348][ T8785] device bridge_slave_0 entered promiscuous mode [ 66.908255][ T8785] bridge0: port 2(bridge_slave_1) entered blocking state [ 66.915453][ T8785] bridge0: port 2(bridge_slave_1) entered disabled state [ 66.923130][ T8785] device bridge_slave_1 entered promiscuous mode [ 66.938683][ T8785] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 66.949102][ T8785] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 66.968068][ T8785] team0: Port device team_slave_0 added [ 66.975728][ T8785] team0: Port device team_slave_1 added [ 67.051266][ T8785] device hsr_slave_0 entered promiscuous mode [ 67.118953][ T8785] device hsr_slave_1 entered promiscuous mode [ 67.206335][ T8785] bridge0: port 2(bridge_slave_1) entered blocking state [ 67.213901][ T8785] bridge0: port 2(bridge_slave_1) entered forwarding state [ 67.221920][ T8785] bridge0: port 1(bridge_slave_0) entered blocking state [ 67.229058][ T8785] bridge0: port 1(bridge_slave_0) entered forwarding state [ 67.263995][ T8785] 8021q: adding VLAN 0 to HW filter on device bond0 [ 67.275755][ T3004] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 67.296184][ T3004] bridge0: port 1(bridge_slave_0) entered disabled state [ 67.304839][ T3004] bridge0: port 2(bridge_slave_1) entered disabled state [ 67.314078][ T3004] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 67.326085][ T8785] 8021q: adding VLAN 0 to HW filter on device team0 [ 67.336994][ T12] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 67.345873][ T12] bridge0: port 1(bridge_slave_0) entered blocking state [ 67.352988][ T12] bridge0: port 1(bridge_slave_0) entered forwarding state [ 67.371371][ T8787] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 67.380086][ T8787] bridge0: port 2(bridge_slave_1) entered blocking state [ 67.387152][ T8787] bridge0: port 2(bridge_slave_1) entered forwarding state [ 67.395374][ T8787] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 67.404969][ T8787] IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready [ 67.419286][ T12] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 67.427707][ T12] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready [ 67.441473][ T8785] hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network [ 67.453226][ T8785] IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready [ 67.461247][ T8787] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready executing program [ 67.477646][ T8785] 8021q: adding VLAN 0 to HW filter on device batadv0 [ 67.514111][ T8785] netlink: 80 bytes leftover after parsing attributes in process `syz-executor573'. [ 67.524676][ T8785] netlink: 48 bytes leftover after parsing attributes in process `syz-executor573'. [ 67.536606][ T8785] [ 67.539140][ T8785] ============================= [ 67.543986][ T8785] WARNING: suspicious RCU usage [ 67.549058][ T8785] 5.3.0+ #0 Not tainted [ 67.553463][ T8785] ----------------------------- [ 67.558317][ T8785] include/net/sch_generic.h:492 suspicious rcu_dereference_check() usage! [ 67.567037][ T8785] [ 67.567037][ T8785] other info that might help us debug this: [ 67.567037][ T8785] [ 67.577324][ T8785] [ 67.577324][ T8785] rcu_scheduler_active = 2, debug_locks = 1 [ 67.585453][ T8785] 3 locks held by syz-executor573/8785: [ 67.591025][ T8785] #0: ffffffff88fab240 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x2dc/0x2570 [ 67.600530][ T8785] #1: ffffffff88fab240 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x35b0 [ 67.609929][ T8785] #2: ffff8880a9965380 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_queue_xmit+0x14b0/0x35b0 [ 67.619942][ T8785] [ 67.619942][ T8785] stack backtrace: [ 67.625831][ T8785] CPU: 0 PID: 8785 Comm: syz-executor573 Not tainted 5.3.0+ #0 [ 67.633357][ T8785] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 67.643416][ T8785] Call Trace: [ 67.646733][ T8785] dump_stack+0x172/0x1f0 [ 67.651161][ T8785] lockdep_rcu_suspicious+0x153/0x15d [ 67.656531][ T8785] netem_enqueue+0x1cfb/0x2d80 [ 67.661292][ T8785] ? lock_acquire+0x190/0x410 [ 67.665965][ T8785] ? __dev_queue_xmit+0x14b0/0x35b0 [ 67.671161][ T8785] __dev_queue_xmit+0x157e/0x35b0 [ 67.676208][ T8785] ? __kasan_check_read+0x11/0x20 [ 67.681245][ T8785] ? netdev_core_pick_tx+0x2f0/0x2f0 [ 67.686524][ T8785] ? find_held_lock+0x10/0x130 [ 67.691291][ T8785] ? __ip_finish_output+0x5fc/0xb90 [ 67.696484][ T8785] ? lock_downgrade+0x920/0x920 [ 67.701328][ T8785] ? ip_finish_output2+0x13e2/0x2570 [ 67.706608][ T8785] ? __ip_finish_output+0x5fc/0xb90 [ 67.711807][ T8785] ? ip_finish_output2+0x13e2/0x2570 [ 67.717088][ T8785] dev_queue_xmit+0x18/0x20 [ 67.721581][ T8785] ? dev_queue_xmit+0x18/0x20 [ 67.726251][ T8785] ip_finish_output2+0x1726/0x2570 [ 67.731355][ T8785] ? nf_ct_deliver_cached_events+0x23d/0x6e0 [ 67.737333][ T8785] ? ip_frag_next+0x910/0x910 [ 67.742002][ T8785] ? ip_mc_output+0xb31/0xf40 [ 67.746675][ T8785] __ip_finish_output+0x5fc/0xb90 [ 67.751692][ T8785] ? __ip_finish_output+0x5fc/0xb90 [ 67.756883][ T8785] ? audit_add_watch+0x250/0xc50 [ 67.761813][ T8785] ip_finish_output+0x38/0x1f0 [ 67.766570][ T8785] ip_mc_output+0x292/0xf40 [ 67.771071][ T8785] ? __ip_queue_xmit+0x1bd0/0x1bd0 [ 67.776183][ T8785] ? __ip_finish_output+0xb90/0xb90 [ 67.781546][ T8785] ? ip_make_skb+0x1b1/0x2c0 [ 67.786258][ T8785] ? ip_reply_glue_bits+0xc0/0xc0 [ 67.791291][ T8785] ip_local_out+0xbb/0x190 [ 67.795725][ T8785] ip_send_skb+0x42/0xf0 [ 67.799983][ T8785] udp_send_skb.isra.0+0x6b2/0x1160 [ 67.805201][ T8785] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 67.811476][ T8785] udp_sendmsg+0x1e96/0x2820 [ 67.816085][ T8785] ? ip_reply_glue_bits+0xc0/0xc0 [ 67.821121][ T8785] ? udp_unicast_rcv_skb.isra.0+0x360/0x360 [ 67.827008][ T8785] ? find_held_lock+0x35/0x130 [ 67.831762][ T8785] ? __might_fault+0x12b/0x1e0 [ 67.836537][ T8785] ? ___might_sleep+0x163/0x280 [ 67.841406][ T8785] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 67.847034][ T8785] ? aa_sk_perm+0x288/0x880 [ 67.851532][ T8785] ? aa_sock_msg_perm.isra.0+0xba/0x170 [ 67.857073][ T8785] inet_sendmsg+0x9e/0xe0 [ 67.861492][ T8785] ? inet_sendmsg+0x9e/0xe0 [ 67.865985][ T8785] ? inet_send_prepare+0x4f0/0x4f0 [ 67.871100][ T8785] sock_sendmsg+0xd7/0x130 [ 67.875526][ T8785] ___sys_sendmsg+0x3e2/0x920 [ 67.880218][ T8785] ? copy_msghdr_from_user+0x440/0x440 [ 67.885667][ T8785] ? __kasan_check_read+0x11/0x20 [ 67.890681][ T8785] ? __kasan_check_read+0x11/0x20 [ 67.895738][ T8785] ? __lock_acquire+0x1703/0x4e70 [ 67.900755][ T8785] ? mark_held_locks+0xf0/0xf0 [ 67.905514][ T8785] ? __might_fault+0x12b/0x1e0 [ 67.910288][ T8785] ? find_held_lock+0x35/0x130 [ 67.915060][ T8785] ? __might_fault+0x12b/0x1e0 [ 67.919817][ T8785] ? lock_downgrade+0x920/0x920 [ 67.925450][ T8785] ? ___might_sleep+0x163/0x280 [ 67.930299][ T8785] __sys_sendmmsg+0x1bf/0x4d0 [ 67.934972][ T8785] ? __ia32_sys_sendmsg+0xb0/0xb0 [ 67.939995][ T8785] ? release_sock+0x156/0x1c0 [ 67.944672][ T8785] ? __sys_connect+0x12d/0x330 [ 67.949427][ T8785] ? __ia32_sys_accept+0xb0/0xb0 [ 67.954382][ T8785] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 67.959832][ T8785] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 67.965286][ T8785] ? do_syscall_64+0x26/0x760 [ 67.969965][ T8785] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 67.976063][ T8785] ? do_syscall_64+0x26/0x760 [ 67.980735][ T8785] __x64_sys_sendmmsg+0x9d/0x100 [ 67.985667][ T8785] do_syscall_64+0xfa/0x760 [ 67.990340][ T8785] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 67.996237][ T8785] RIP: 0033:0x441b59 [ 68.000148][ T8785] 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 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 68.019742][ T8785] RSP: 002b:00007fff53630788 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 [ 68.028163][ T8785] RAX: ffffffffffffffda RBX: 0000315f6576616c RCX: 0000000000441b59 [ 68.036141][ T8785] RDX: 04000000000001a8 RSI: 0000000020007fc0 RDI: 0000000000000005 [ 68.044105][ T8785] RBP: 735f656764697262 R08: 0000000001bbbbbb R09: 0000000001bbbbbb [ 68.052079][ T8785] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 68.060040][ T8785] R13: 00000000004030f0 R14: 0000000000000000 R15: 0000000000000000