INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] 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 'ci-upstream-kasan-gce-386-1,10.128.0.42' (ECDSA) to the list of known hosts. 2017/10/24 03:07:58 parsed 1 programs 2017/10/24 03:07:58 executed programs: 0 2017/10/24 03:08:03 executed programs: 588 syzkaller login: [ 62.305371] refcount_t: underflow; use-after-free. [ 62.306343] ------------[ cut here ]------------ [ 62.307010] WARNING: CPU: 0 PID: 5749 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 62.309718] Kernel panic - not syncing: panic_on_warn set ... [ 62.309718] [ 62.310781] CPU: 0 PID: 5749 Comm: syz-executor5 Not tainted 4.14.0-rc6+ #55 [ 62.311731] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.313458] Call Trace: [ 62.314079] dump_stack+0x194/0x257 [ 62.314749] ? arch_local_irq_restore+0x53/0x53 [ 62.315391] panic+0x1e4/0x417 [ 62.315862] ? __warn+0x1d9/0x1d9 [ 62.316681] ? show_regs_print_info+0x65/0x65 [ 62.317336] ? refcount_sub_and_test+0x167/0x1b0 [ 62.318013] __warn+0x1c4/0x1d9 [ 62.318468] ? refcount_sub_and_test+0x167/0x1b0 [ 62.319112] report_bug+0x211/0x2d0 [ 62.319626] fixup_bug+0x40/0x90 [ 62.320165] do_trap+0x260/0x390 [ 62.320654] do_error_trap+0x120/0x390 [ 62.321217] ? do_trap+0x390/0x390 [ 62.321708] ? refcount_sub_and_test+0x167/0x1b0 [ 62.322388] ? vprintk_emit+0x3ea/0x590 [ 62.323067] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 62.323725] do_invalid_op+0x1b/0x20 [ 62.324241] invalid_op+0x18/0x20 [ 62.324732] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 62.325462] RSP: 0018:ffff8801c8c4e390 EFLAGS: 00010286 [ 62.330447] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 62.337702] RDX: 0000000000000026 RSI: 1ffff10039189c32 RDI: ffffed0039189c66 [ 62.344961] RBP: ffff8801c8c4e420 R08: 0000000000000001 R09: 0000000000000000 [ 62.352212] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10039189c73 [ 62.359464] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801c9b999fc [ 62.366759] ? refcount_inc+0x50/0x50 [ 62.370557] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 62.375308] ? sctp_association_free+0x2d0/0x930 [ 62.380053] ? sctp_do_sm+0x28e7/0x6dd0 [ 62.384011] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 62.388746] ? sctp_close+0x3c6/0x980 [ 62.392516] ? inet_release+0xed/0x1c0 [ 62.396379] sctp_wfree+0x183/0x620 [ 62.399974] ? __sctp_write_space+0x910/0x910 [ 62.404443] skb_release_head_state+0x124/0x200 [ 62.409081] skb_release_all+0x15/0x60 [ 62.412938] consume_skb+0x153/0x490 [ 62.416622] ? sctp_chunk_put+0x99/0x420 [ 62.420652] ? alloc_skb_with_frags+0x710/0x710 [ 62.425289] ? sctp_chunk_hold+0x20/0x20 [ 62.429324] ? refcount_sub_and_test+0x115/0x1b0 [ 62.434048] ? refcount_inc+0x50/0x50 [ 62.437826] ? mark_held_locks+0xaf/0x100 [ 62.441954] ? sctp_datamsg_put+0x456/0x560 [ 62.446255] sctp_chunk_put+0x29c/0x420 [ 62.450202] ? sctp_chunk_hold+0x20/0x20 [ 62.454236] ? sctp_transport_dst_confirm+0x50/0x50 [ 62.459231] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 62.464397] ? print_irqtrace_events+0x270/0x270 [ 62.469130] sctp_chunk_free+0x53/0x60 [ 62.472989] __sctp_outq_teardown+0xc7d/0x15a0 [ 62.477552] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 62.482455] ? print_irqtrace_events+0x270/0x270 [ 62.487183] ? lock_acquire+0x1d5/0x580 [ 62.491132] ? print_irqtrace_events+0x270/0x270 [ 62.495863] ? print_irqtrace_events+0x270/0x270 [ 62.500587] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 62.505763] ? __lock_acquire+0x6aa/0x3d50 [ 62.509976] ? check_noncircular+0x20/0x20 [ 62.514182] ? print_irqtrace_events+0x270/0x270 [ 62.518996] ? __lock_acquire+0x6aa/0x3d50 [ 62.523211] ? lock_acquire+0x1d5/0x580 [ 62.527152] ? lock_acquire+0x1d5/0x580 [ 62.531095] ? lock_timer_base+0x1a3/0x2b0 [ 62.535304] ? find_held_lock+0x35/0x1d0 [ 62.539344] ? sock_def_wakeup+0x1f9/0x350 [ 62.543549] ? lock_downgrade+0x990/0x990 [ 62.547670] ? lock_release+0xa40/0xa40 [ 62.551620] sctp_outq_free+0x15/0x20 [ 62.555391] sctp_association_free+0x2d0/0x930 [ 62.559959] ? sctp_asconf_queue_teardown+0x700/0x700 [ 62.565121] ? sock_def_wakeup+0x222/0x350 [ 62.569322] ? sk_dst_check+0x560/0x560 [ 62.573266] ? sctp_association_put+0x74/0x2f0 [ 62.577815] ? sctp_association_hold+0x20/0x20 [ 62.582368] ? check_noncircular+0x20/0x20 [ 62.586581] sctp_do_sm+0x28e7/0x6dd0 [ 62.590368] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 62.596400] ? print_irqtrace_events+0x270/0x270 [ 62.601133] ? __lock_acquire+0x6aa/0x3d50 [ 62.606526] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 62.611686] ? __lock_acquire+0x6aa/0x3d50 [ 62.615895] ? print_irqtrace_events+0x270/0x270 [ 62.620632] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 62.625794] ? find_held_lock+0x35/0x1d0 [ 62.629836] ? skb_dequeue+0x12a/0x180 [ 62.633692] ? lock_downgrade+0x990/0x990 [ 62.637814] ? do_raw_spin_trylock+0x190/0x190 [ 62.642371] ? mark_held_locks+0xaf/0x100 [ 62.646498] ? trace_hardirqs_on+0xd/0x10 [ 62.650623] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 62.655182] sctp_close+0x3c6/0x980 [ 62.658776] ? is_bpf_text_address+0xa4/0x120 [ 62.663251] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 62.668494] ? __save_stack_trace+0x7e/0xd0 [ 62.672787] ? check_noncircular+0x20/0x20 [ 62.676993] ? depot_save_stack+0x12c/0x490 [ 62.681294] ? locks_remove_file+0x3fa/0x5a0 [ 62.685676] ? fcntl_setlk+0x10c0/0x10c0 [ 62.689705] ? kmem_cache_free+0x77/0x280 [ 62.693823] ? __fsnotify_parent+0xb4/0x3a0 [ 62.698114] ? ip_mc_drop_socket+0x1ce/0x230 [ 62.702497] inet_release+0xed/0x1c0 [ 62.706183] sock_release+0x8d/0x1e0 [ 62.709871] ? sock_release+0x1e0/0x1e0 [ 62.713822] sock_close+0x16/0x20 [ 62.717245] __fput+0x327/0x7e0 [ 62.720500] ? fput+0x140/0x140 [ 62.723763] ____fput+0x15/0x20 [ 62.727018] task_work_run+0x199/0x270 [ 62.730880] ? task_work_cancel+0x210/0x210 [ 62.735172] ? _raw_spin_unlock+0x22/0x30 [ 62.739290] ? switch_task_namespaces+0x87/0xc0 [ 62.743934] do_exit+0x9b5/0x1ad0 [ 62.747356] ? __might_sleep+0x95/0x190 [ 62.751304] ? mm_update_next_owner+0x930/0x930 [ 62.755939] ? find_held_lock+0x35/0x1d0 [ 62.759979] ? futex_wait+0x402/0x990 [ 62.763751] ? lock_downgrade+0x990/0x990 [ 62.767875] ? do_raw_spin_trylock+0x190/0x190 [ 62.772426] ? fault_in_user_writeable+0x90/0x90 [ 62.777156] ? futex_wake+0x680/0x680 [ 62.780933] ? drop_futex_key_refs.isra.13+0x63/0xb0 [ 62.786006] ? futex_wait+0x69e/0x990 [ 62.789789] ? check_noncircular+0x20/0x20 [ 62.794083] ? futex_wait_setup+0x3d0/0x3d0 [ 62.798372] ? lock_downgrade+0x990/0x990 [ 62.802488] ? hash_futex+0x15/0x210 [ 62.806171] ? drop_futex_key_refs.isra.13+0x63/0xb0 [ 62.811242] ? futex_wake+0x2ca/0x680 [ 62.815012] ? handle_mm_fault+0x410/0x8d0 [ 62.819219] ? find_held_lock+0x35/0x1d0 [ 62.823260] ? get_signal+0x7ae/0x16d0 [ 62.827118] ? lock_downgrade+0x990/0x990 [ 62.831244] do_group_exit+0x149/0x400 [ 62.835099] ? __lock_is_held+0xb6/0x140 [ 62.839127] ? SyS_exit+0x30/0x30 [ 62.842549] ? _raw_spin_unlock_irq+0x27/0x70 [ 62.847027] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 62.852020] get_signal+0x73f/0x16d0 [ 62.855714] ? ptrace_notify+0x130/0x130 [ 62.859752] ? __fd_install+0x2f7/0x6a0 [ 62.863691] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 62.868421] ? get_unused_fd_flags+0x190/0x190 [ 62.872994] do_signal+0x94/0x1ee0 [ 62.876506] ? copy_user_generic_unrolled+0x89/0xc0 [ 62.881492] ? _copy_to_user+0xa2/0xc0 [ 62.885356] ? setup_sigcontext+0x7d0/0x7d0 [ 62.889646] ? fput+0xd2/0x140 [ 62.892812] ? SYSC_accept4+0x4ec/0x850 [ 62.896761] ? kernel_accept+0x2f0/0x2f0 [ 62.900799] ? ___sys_recvmsg+0x620/0x620 [ 62.904928] ? exit_to_usermode_loop+0x8c/0x310 [ 62.909572] exit_to_usermode_loop+0x214/0x310 [ 62.914125] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 62.919632] ? lock_downgrade+0x990/0x990 [ 62.923748] ? do_fast_syscall_32+0x158/0xf05 [ 62.928218] do_fast_syscall_32+0x83e/0xf05 [ 62.932507] ? compat_start_thread+0x80/0x80 [ 62.936890] ? do_int80_syscall_32+0x940/0x940 [ 62.941451] ? syscall_return_slowpath+0x2b3/0x510 [ 62.946347] ? finish_task_switch+0x1aa/0x740 [ 62.950812] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 62.955801] ? sysret32_from_system_call+0x5/0x3b [ 62.960617] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 62.965439] entry_SYSENTER_compat+0x51/0x60 [ 62.969814] RIP: 0023:0xf7f42c79 [ 62.973145] RSP: 002b:00000000f7f1d10c EFLAGS: 00000296 ORIG_RAX: 00000000000000f0 [ 62.980823] RAX: fffffffffffffe00 RBX: 00000000081680b4 RCX: 0000000000000000 [ 62.988063] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 62.995299] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 63.002536] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 63.009771] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 63.017639] Dumping ftrace buffer: [ 63.021209] (ftrace buffer empty) [ 63.024888] Kernel Offset: disabled [ 63.028485] Rebooting in 86400 seconds..