[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.67' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 33.867573] audit: type=1400 audit(1593737333.367:8): avc: denied { execmem } for pid=6333 comm="syz-executor124" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 33.871331] [ 33.889577] ============================= [ 33.895608] WARNING: suspicious RCU usage [ 33.899748] 4.14.184-syzkaller #0 Not tainted [ 33.905005] ----------------------------- [ 33.909251] net/tipc/bearer.c:177 suspicious rcu_dereference_protected() usage! [ 33.917947] [ 33.917947] other info that might help us debug this: [ 33.917947] [ 33.928725] [ 33.928725] rcu_scheduler_active = 2, debug_locks = 1 [ 33.935677] 2 locks held by syz-executor124/6333: [ 33.940635] #0: (cb_lock){++++}, at: [] genl_rcv+0x15/0x40 [ 33.948462] #1: (genl_mutex){+.+.}, at: [] genl_rcv_msg+0x112/0x140 [ 33.956792] [ 33.956792] stack backtrace: [ 33.961353] CPU: 0 PID: 6333 Comm: syz-executor124 Not tainted 4.14.184-syzkaller #0 [ 33.969221] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.978781] Call Trace: [ 33.981366] dump_stack+0x1b2/0x283 [ 33.985006] tipc_bearer_find+0x1ff/0x2f0 [ 33.989240] tipc_nl_compat_link_set+0x40b/0xb80 [ 33.994237] tipc_nl_compat_doit+0x18d/0x510 [ 33.998724] ? unwind_next_frame+0xe38/0x1700 [ 34.003284] ? tipc_nl_compat_link_stat_dump+0x1b90/0x1b90 [ 34.009074] ? cap_capable+0x1c4/0x230 [ 34.013363] ? security_capable+0x88/0xb0 [ 34.017894] ? ns_capable_common+0x127/0x150 [ 34.022380] tipc_nl_compat_recv+0x95c/0xa10 [ 34.026771] ? tipc_nl_compat_doit+0x510/0x510 [ 34.031348] ? tipc_nl_node_dump+0xc20/0xc20 [ 34.036189] ? __tipc_add_link_prop.isra.0+0x1a0/0x1a0 [ 34.041508] ? lock_acquire+0x170/0x3f0 [ 34.045913] genl_family_rcv_msg+0x57c/0xb30 [ 34.050306] ? lock_is_held_type+0x1f5/0x210 [ 34.054703] ? genl_rcv+0x40/0x40 [ 34.058138] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 34.063700] genl_rcv_msg+0xaf/0x140 [ 34.067400] netlink_rcv_skb+0x127/0x370 [ 34.071524] ? genl_family_rcv_msg+0xb30/0xb30 [ 34.076119] ? netlink_ack+0x970/0x970 [ 34.079991] ? lock_acquire+0x170/0x3f0 [ 34.083981] genl_rcv+0x24/0x40 [ 34.087251] netlink_unicast+0x437/0x610 [ 34.091291] ? netlink_sendskb+0x50/0x50 [ 34.095334] netlink_sendmsg+0x64a/0xbb0 [ 34.099481] ? nlmsg_notify+0x160/0x160 [ 34.103792] ? move_addr_to_kernel.part.0+0xf0/0xf0 [ 34.108991] ? security_socket_sendmsg+0x83/0xb0 [ 34.113963] ? nlmsg_notify+0x160/0x160 [ 34.121562] sock_sendmsg+0xb5/0x100 [ 34.125455] ___sys_sendmsg+0x70a/0x840 [ 34.129422] ? copy_msghdr_from_user+0x380/0x380 [ 34.134621] ? lock_downgrade+0x6e0/0x6e0 [ 34.138760] ? __lock_acquire+0x655/0x42a0 [ 34.143178] ? trace_hardirqs_on+0x10/0x10 [ 34.147414] ? trace_hardirqs_on+0x10/0x10 [ 34.151653] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 34.157130] ? dentry_free+0xc6/0x120 [ 34.160934] ? rcu_read_lock_sched_held+0x10a/0x130 [ 34.166036] ? kmem_cache_free+0x23a/0x2b0 [ 34.170293] ? mntput_no_expire+0xc7/0x800 [ 34.174509] ? __fget_light+0x16a/0x1f0 [ 34.178671] ? sockfd_lookup_light+0xb2/0x160 [ 34.184497] __sys_sendmsg+0xa3/0x120 [ 34.188530] ? SyS_shutdown+0x160/0x160 [ 34.192575] ? _raw_spin_unlock_irq+0x24/0x90 [ 34.197266] SyS_sendmsg+0x27/0x40 [ 34.201928] ? __sys_sendmsg+0x120/0x120 [ 34.206630] do_syscall_64+0x1d5/0x640 [ 34.210717] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 34.215904] RIP: 0033:0x444239 [ 34.2190