[ 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 '10.128.10.12' (ECDSA) to the list of known hosts. syzkaller login: [ 32.971724] audit: type=1400 audit(1594056698.178:8): avc: denied { execmem } for pid=6333 comm="syz-executor602" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 33.219903] IPVS: ftp: loaded support on port[0] = 21 executing program [ 34.048808] netlink: 28 bytes leftover after parsing attributes in process `syz-executor602'. [ 34.057885] [ 34.059627] ============================= [ 34.064565] WARNING: suspicious RCU usage [ 34.068898] 4.14.184-syzkaller #0 Not tainted [ 34.073376] ----------------------------- [ 34.077498] net/sched/act_sample.c:95 suspicious rcu_dereference_protected() usage! [ 34.085339] [ 34.085339] other info that might help us debug this: [ 34.085339] [ 34.093685] [ 34.093685] rcu_scheduler_active = 2, debug_locks = 1 [ 34.100397] 1 lock held by syz-executor602/6334: [ 34.105136] #0: (rtnl_mutex){+.+.}, at: [] rtnetlink_rcv_msg+0x31d/0xb10 [ 34.113759] [ 34.113759] stack backtrace: [ 34.118343] CPU: 1 PID: 6334 Comm: syz-executor602 Not tainted 4.14.184-syzkaller #0 [ 34.126206] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.135534] Call Trace: [ 34.138102] dump_stack+0x1b2/0x283 [ 34.142230] tcf_sample_init+0x71c/0x8c0 [ 34.146378] ? tcf_sample_cleanup_rcu+0x80/0x80 [ 34.151037] tcf_action_init_1+0x51a/0x9f0 [ 34.155255] ? tcf_action_dump_old+0x80/0x80 [ 34.159644] ? depot_save_stack+0x1dd/0x401 [ 34.163971] ? nla_parse+0x162/0x220 [ 34.167670] tcf_action_init+0x26d/0x400 [ 34.171714] ? tcf_action_init_1+0x9f0/0x9f0 [ 34.176117] ? basic_change+0x2b3/0xf00 [ 34.180085] ? tc_ctl_tfilter+0xf13/0x18e7 [ 34.184315] ? rtnetlink_rcv_msg+0x3be/0xb10 [ 34.188795] ? sock_sendmsg+0xb5/0x100 [ 34.192672] ? ___sys_sendmsg+0x349/0x840 [ 34.196803] ? __sys_sendmmsg+0x129/0x330 [ 34.200998] ? fs_reclaim_acquire+0x10/0x10 [ 34.205308] tcf_exts_validate+0x2d7/0x490 [ 34.209533] ? tcf_exts_change+0x120/0x120 [ 34.213751] basic_change+0x3ef/0xf00 [ 34.217536] ? basic_init+0xf0/0xf0 [ 34.221194] ? basic_init+0xf0/0xf0 [ 34.224804] tc_ctl_tfilter+0xf13/0x18e7 [ 34.228849] ? tcf_chain_tp_remove.isra.0+0x200/0x200 [ 34.234032] ? rtnetlink_rcv_msg+0x2e8/0xb10 [ 34.238436] ? tcf_chain_tp_remove.isra.0+0x200/0x200 [ 34.243614] rtnetlink_rcv_msg+0x3be/0xb10 [ 34.247840] ? rtnl_calcit.isra.0+0x3a0/0x3a0 [ 34.252483] ? __netlink_lookup+0x332/0x5c0 [ 34.256790] netlink_rcv_skb+0x127/0x370 [ 34.260834] ? rtnl_calcit.isra.0+0x3a0/0x3a0 [ 34.273435] ? netlink_ack+0x970/0x970 [ 34.277304] netlink_unicast+0x437/0x610 [ 34.281342] ? netlink_sendskb+0x50/0x50 [ 34.285378] netlink_sendmsg+0x64a/0xbb0 [ 34.289416] ? nlmsg_notify+0x160/0x160 [ 34.293367] ? move_addr_to_kernel.part.0+0xf0/0xf0 [ 34.298364] ? security_socket_sendmsg+0x83/0xb0 [ 34.303095] ? nlmsg_notify+0x160/0x160 [ 34.307043] sock_sendmsg+0xb5/0x100 [ 34.310733] ___sys_sendmsg+0x349/0x840 [ 34.314680] ? netlink_sendmsg+0x8b3/0xbb0 [ 34.318905] ? copy_msghdr_from_user+0x380/0x380 [ 34.323638] ? trace_hardirqs_on+0x10/0x10 [ 34.327846] ? __lock_acquire+0x655/0x42a0 [ 34.332070] ? ___sys_sendmsg+0x44d/0x840 [ 34.336195] ? trace_hardirqs_on+0x10/0x10 [ 34.340404] ? trace_hardirqs_on+0x10/0x10 [ 34.344614] ? __might_fault+0x104/0x1b0 [ 34.348652] ? lock_acquire+0x170/0x3f0 [ 34.352605] __sys_sendmmsg+0x129/0x330 [ 34.356561] ? SyS_sendmsg+0x40/0x40 [ 34.360249] ? __might_fault+0x177/0x1b0 [ 34.364289] ? sockfd_lookup_light+0xb2/0x160 [ 34.368759] ? __sys_sendmsg+0xb6/0x120 [ 34.372708] ? SyS_shutdown+0x160/0x160 [ 34.376659] ? up_read+0x17/0x30 [ 34.380002] SyS_sendmmsg+0x2f/0x50 [ 34.383603] ? __sys_sendmmsg+0x330/0x330 [ 34.387725] do_syscall_64+0x1d5/0x640 [ 34.391591] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 34.396755] RIP: 0033:0x440c69 [ 34.399924] RSP: 002b:00007ffd2322a618 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 [ 34.407621] RAX: ffffffffffffffda RBX: 00000000004a2490 RCX: 0000000000440c69 [ 34.414867] RDX: 010efe10675dec16 RSI: 0000000020000200 RDI: 0000000000000003 [ 34.422214] RBP: 00007ffd2322a620 R08: 0000000120080522 R09: 0000000120080522 [ 34.429471] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004a2490 [ 34.436723] R13: 0000000000402200 R14: 0000000000000000 R15: 0000000000000000