[ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.15.211' (ECDSA) to the list of known hosts. syzkaller login: [ 34.576397] audit: type=1400 audit(1593733657.604:8): avc: denied { execmem } for pid=6335 comm="syz-executor996" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 34.815010] IPVS: ftp: loaded support on port[0] = 21 executing program [ 35.632890] [ 35.634582] ============================= [ 35.638873] WARNING: suspicious RCU usage [ 35.647246] 4.14.184-syzkaller #0 Not tainted [ 35.653204] ----------------------------- [ 35.658920] net/sched/act_sample.c:95 suspicious rcu_dereference_protected() usage! [ 35.669528] [ 35.669528] other info that might help us debug this: [ 35.669528] [ 35.677890] [ 35.677890] rcu_scheduler_active = 2, debug_locks = 1 [ 35.684617] 1 lock held by syz-executor996/6336: [ 35.689373] #0: (rtnl_mutex){+.+.}, at: [] rtnetlink_rcv_msg+0x31d/0xb10 [ 35.702923] [ 35.702923] stack backtrace: [ 35.708949] CPU: 0 PID: 6336 Comm: syz-executor996 Not tainted 4.14.184-syzkaller #0 [ 35.718943] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.728314] Call Trace: [ 35.731174] dump_stack+0x1b2/0x283 [ 35.734893] tcf_sample_init+0x71c/0x8c0 [ 35.738973] ? tcf_sample_cleanup_rcu+0x80/0x80 [ 35.743732] tcf_action_init_1+0x51a/0x9f0 [ 35.748488] ? tcf_action_dump_old+0x80/0x80 [ 35.752980] ? depot_save_stack+0x1dd/0x401 [ 35.757450] ? nla_parse+0x162/0x220 [ 35.762250] tcf_action_init+0x26d/0x400 [ 35.766865] ? tcf_action_init_1+0x9f0/0x9f0 [ 35.771530] ? basic_change+0x2b3/0xf00 [ 35.775503] ? tc_ctl_tfilter+0xf13/0x18e7 [ 35.779720] ? rtnetlink_rcv_msg+0x3be/0xb10 [ 35.784308] ? lock_acquire+0x170/0x3f0 [ 35.788256] ? lock_downgrade+0x6e0/0x6e0 [ 35.792578] tcf_exts_validate+0x2d7/0x490 [ 35.796801] ? tcf_exts_change+0x120/0x120 [ 35.803105] basic_change+0x3ef/0xf00 [ 35.806899] ? basic_init+0xf0/0xf0 [ 35.810507] ? basic_init+0xf0/0xf0 [ 35.814153] tc_ctl_tfilter+0xf13/0x18e7 [ 35.818200] ? tcf_chain_tp_remove.isra.0+0x200/0x200 [ 35.823370] ? rtnetlink_rcv_msg+0x2e8/0xb10 [ 35.827760] ? tcf_chain_tp_remove.isra.0+0x200/0x200 [ 35.832924] rtnetlink_rcv_msg+0x3be/0xb10 [ 35.837141] ? rtnl_calcit.isra.0+0x3a0/0x3a0 [ 35.841650] ? __netlink_lookup+0x332/0x5c0 [ 35.845955] netlink_rcv_skb+0x127/0x370 [ 35.849990] ? rtnl_calcit.isra.0+0x3a0/0x3a0 [ 35.854483] ? netlink_ack+0x970/0x970 [ 35.858349] netlink_unicast+0x437/0x610 [ 35.862385] ? netlink_sendskb+0x50/0x50 [ 35.866443] netlink_sendmsg+0x64a/0xbb0 [ 35.870478] ? nlmsg_notify+0x160/0x160 [ 35.874427] ? move_addr_to_kernel.part.0+0xf0/0xf0 [ 35.879421] ? security_socket_sendmsg+0x83/0xb0 [ 35.884151] ? nlmsg_notify+0x160/0x160 [ 35.888101] sock_sendmsg+0xb5/0x100 [ 35.891788] ___sys_sendmsg+0x349/0x840 [ 35.895753] ? netlink_sendmsg+0x8b3/0xbb0 [ 35.899976] ? copy_msghdr_from_user+0x380/0x380 [ 35.904717] ? trace_hardirqs_on+0x10/0x10 [ 35.909003] ? __lock_acquire+0x655/0x42a0 [ 35.913211] ? ___sys_sendmsg+0x44d/0x840 [ 35.917333] ? trace_hardirqs_on+0x10/0x10 [ 35.921542] ? trace_hardirqs_on+0x10/0x10 [ 35.925800] ? __might_fault+0x104/0x1b0 [ 35.929857] ? lock_acquire+0x170/0x3f0 [ 35.933810] __sys_sendmmsg+0x129/0x330 [ 35.937811] ? SyS_sendmsg+0x40/0x40 [ 35.941500] ? __might_fault+0x177/0x1b0 [ 35.945537] ? sockfd_lookup_light+0xb2/0x160 [ 35.950206] ? __sys_sendmsg+0xb6/0x120 [ 35.954315] ? SyS_shutdown+0x160/0x160 [ 35.958278] ? up_read+0x17/0x30 [ 35.961628] SyS_sendmmsg+0x2f/0x50 [ 35.965298] ? __sys_sendmmsg+0x330/0x330 [ 35.969474] do_syscall_64+0x1d5/0x640 [ 35.973386] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 35.978740] RIP: 0033:0x440e99 [ 35.981921] RSP: 002b:00007ffe64ca8b18 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 [ 35.989616] RAX: ffffffffffffffda RBX: 00000000004a2670 RCX: 0000000000440e99 [ 35.996888] RDX: 010efe10675dec16 RSI: 0000000020000200 RDI: 0000000000000003 [ 36.004139] RBP: 00007ffe64ca8b20 R08: 0000000120080522 R09: 0000000120080522 [ 36.011382] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004a2670 [ 36.018626] R13: 0000000000402430 R14: 0000000000000000 R15: 0000000000000000