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-mmots-kasan-gce-2,10.128.0.9' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program syzkaller login: [ 41.460606] refcount_t: underflow; use-after-free. [ 41.461531] ------------[ cut here ]------------ [ 41.462358] WARNING: CPU: 0 PID: 3052 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 41.463542] Kernel panic - not syncing: panic_on_warn set ... [ 41.463542] [ 41.464546] CPU: 0 PID: 3052 Comm: syzkaller613874 Not tainted 4.14.0-rc5-mm1+ #20 [ 41.465554] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.466791] Call Trace: [ 41.467151] dump_stack+0x194/0x257 [ 41.467644] ? arch_local_irq_restore+0x53/0x53 [ 41.468291] ? vsnprintf+0x1ed/0x1900 [ 41.468815] panic+0x1e4/0x41c [ 41.469252] ? refcount_error_report+0x214/0x214 [ 41.469885] ? show_regs_print_info+0x65/0x65 [ 41.470510] ? __warn+0x1a9/0x1e0 [ 41.470981] ? refcount_sub_and_test+0x167/0x1b0 [ 41.471615] __warn+0x1c4/0x1e0 [ 41.472060] ? refcount_sub_and_test+0x167/0x1b0 [ 41.472696] report_bug+0x211/0x2d0 [ 41.473192] fixup_bug+0x40/0x90 [ 41.473671] do_trap+0x260/0x390 [ 41.474133] do_error_trap+0x120/0x390 [ 41.474656] ? vprintk_emit+0x49b/0x590 [ 41.475193] ? do_trap+0x390/0x390 [ 41.475674] ? refcount_sub_and_test+0x167/0x1b0 [ 41.476308] ? vprintk_emit+0x3ea/0x590 [ 41.476897] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 41.477548] do_invalid_op+0x1b/0x20 [ 41.478048] invalid_op+0x18/0x20 [ 41.478515] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 41.479228] RSP: 0018:ffff8801d1c069c8 EFLAGS: 00010282 [ 41.479940] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 41.481681] RDX: 0000000000000026 RSI: 1ffff1003a380cf9 RDI: ffffed003a380d2d [ 41.488918] RBP: ffff8801d1c06a58 R08: 0000000000000001 R09: 0000000000000000 [ 41.496153] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a380d3a [ 41.503392] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d9b00a3c [ 41.510648] ? refcount_sub_and_test+0x167/0x1b0 [ 41.515374] ? refcount_inc+0x50/0x50 [ 41.519143] ? sctp_outq_free+0x15/0x20 [ 41.523087] ? sctp_do_sm+0x271b/0x6a30 [ 41.527028] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 41.531749] ? sctp_close+0x3c6/0x980 [ 41.535519] ? inet_release+0xed/0x1c0 [ 41.539372] ? sock_release+0x8d/0x1e0 [ 41.543231] sctp_wfree+0x183/0x620 [ 41.546827] ? __sctp_write_space+0x910/0x910 [ 41.551291] skb_release_head_state+0x124/0x200 [ 41.555927] skb_release_all+0x15/0x60 [ 41.559781] consume_skb+0x153/0x490 [ 41.563463] ? sctp_chunk_put+0x99/0x420 [ 41.567493] ? alloc_skb_with_frags+0x750/0x750 [ 41.572128] ? sctp_chunk_hold+0x20/0x20 [ 41.576162] ? refcount_sub_and_test+0x115/0x1b0 [ 41.580886] ? refcount_inc+0x50/0x50 [ 41.584653] ? mark_held_locks+0xaf/0x100 [ 41.588770] ? sctp_datamsg_put+0x456/0x560 [ 41.593064] sctp_chunk_put+0x29c/0x420 [ 41.597007] ? sctp_chunk_hold+0x20/0x20 [ 41.601042] ? sctp_transport_dst_confirm+0x50/0x50 [ 41.606031] ? sctp_sched_fcfs_dequeue+0x198/0x290 [ 41.610927] ? sctp_sched_dequeue_common+0x5d0/0x5d0 [ 41.616004] sctp_chunk_free+0x53/0x60 [ 41.619860] __sctp_outq_teardown+0xa5b/0x1230 [ 41.624417] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 41.629320] ? print_irqtrace_events+0x270/0x270 [ 41.634049] ? print_irqtrace_events+0x270/0x270 [ 41.638771] ? trace_hardirqs_off+0x10/0x10 [ 41.643060] ? __bfs+0xaa/0x750 [ 41.646309] ? __is_insn_slot_addr+0x1fc/0x330 [ 41.650858] ? check_noncircular+0x20/0x20 [ 41.655061] ? default_wake_function+0x30/0x50 [ 41.659613] ? autoremove_wake_function+0x78/0x350 [ 41.664511] ? bpf_prog_kallsyms_find+0xbd/0x440 [ 41.669239] ? find_held_lock+0x35/0x1d0 [ 41.673274] ? find_held_lock+0x35/0x1d0 [ 41.677310] ? sock_def_wakeup+0x1f9/0x350 [ 41.681515] ? lock_downgrade+0x990/0x990 [ 41.685636] ? lock_release+0xa40/0xa40 [ 41.689584] sctp_outq_free+0x15/0x20 [ 41.693353] sctp_association_free+0x2d0/0x930 [ 41.697908] ? sctp_asconf_queue_teardown+0x700/0x700 [ 41.703067] ? sock_def_wakeup+0x222/0x350 [ 41.707272] ? sk_dst_check+0x560/0x560 [ 41.711234] sctp_do_sm+0x271b/0x6a30 [ 41.715013] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 41.721053] ? print_irqtrace_events+0x270/0x270 [ 41.725777] ? __lock_acquire+0x6aa/0x3d50 [ 41.729977] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 41.735137] ? print_irqtrace_events+0x270/0x270 [ 41.739892] ? find_held_lock+0x35/0x1d0 [ 41.743928] ? skb_dequeue+0x12a/0x180 [ 41.747783] ? lock_downgrade+0x990/0x990 [ 41.751903] ? do_raw_spin_trylock+0x190/0x190 [ 41.756459] ? mark_held_locks+0xaf/0x100 [ 41.760582] ? trace_hardirqs_on+0xd/0x10 [ 41.764704] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 41.769261] sctp_close+0x3c6/0x980 [ 41.772864] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 41.778105] ? __lock_acquire+0x6aa/0x3d50 [ 41.782309] ? check_noncircular+0x20/0x20 [ 41.786515] ? __lock_acquire+0x6aa/0x3d50 [ 41.790718] ? check_noncircular+0x20/0x20 [ 41.794922] ? locks_remove_file+0x3fa/0x5a0 [ 41.799303] ? fcntl_setlk+0x10c0/0x10c0 [ 41.803336] ? __fsnotify_parent+0xb4/0x3a0 [ 41.807623] ? ip_mc_drop_socket+0x1ce/0x230 [ 41.812003] inet_release+0xed/0x1c0 [ 41.815688] sock_release+0x8d/0x1e0 [ 41.819369] ? sock_release+0x1e0/0x1e0 [ 41.823309] sock_close+0x16/0x20 [ 41.826730] __fput+0x327/0x7e0 [ 41.829983] ? fput+0x140/0x140 [ 41.833233] ? _raw_spin_unlock_irq+0x27/0x70 [ 41.837702] ____fput+0x15/0x20 [ 41.840949] task_work_run+0x199/0x270 [ 41.844807] ? task_work_cancel+0x210/0x210 [ 41.849099] ? __do_page_fault+0x3d6/0xd60 [ 41.853310] get_signal+0x1343/0x16d0 [ 41.857088] ? mm_fault_error+0x2c0/0x2c0 [ 41.861207] ? ptrace_notify+0x130/0x130 [ 41.865237] ? check_noncircular+0x20/0x20 [ 41.869443] ? __do_page_fault+0xd60/0xd60 [ 41.873644] ? do_page_fault+0xee/0x720 [ 41.877588] ? __do_page_fault+0xd60/0xd60 [ 41.881801] ? check_noncircular+0x20/0x20 [ 41.886006] ? find_held_lock+0x35/0x1d0 [ 41.890036] ? retint_kernel+0x10/0x10 [ 41.893902] do_signal+0x94/0x1ee0 [ 41.897426] ? put_unused_fd+0x62/0x70 [ 41.901283] ? lock_downgrade+0x990/0x990 [ 41.905400] ? setup_sigcontext+0x7d0/0x7d0 [ 41.909690] ? do_raw_spin_trylock+0x190/0x190 [ 41.914244] ? __put_unused_fd+0x183/0x250 [ 41.918446] ? alloc_fdtable+0x280/0x280 [ 41.922475] ? cpumask_weight.constprop.1+0x48/0x48 [ 41.927460] ? _copy_to_user+0xa2/0xc0 [ 41.931318] ? _raw_spin_unlock+0x22/0x30 [ 41.935434] ? fput+0xd2/0x140 [ 41.938594] ? SYSC_accept4+0x4ec/0x850 [ 41.942539] ? exit_to_usermode_loop+0x8c/0x310 [ 41.947180] exit_to_usermode_loop+0x214/0x310 [ 41.951732] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 41.957237] ? _raw_spin_unlock_irq+0x27/0x70 [ 41.961700] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 41.966687] syscall_return_slowpath+0x42f/0x510 [ 41.971409] ? finish_task_switch+0x1f6/0x740 [ 41.975871] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 41.980856] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 41.985751] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 41.990734] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 41.995463] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 42.000184] RIP: 0033:0x447409 [ 42.003342] RSP: 002b:00007f68e4dcbdc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000120 [ 42.011015] RAX: fffffffffffffff2 RBX: 0000000000000000 RCX: 0000000000447409 [ 42.018252] RDX: 0000000020137ffc RSI: 0000000020b53ff0 RDI: 0000000000000003 [ 42.025488] RBP: 0000000000000000 R08: 00007f68e4dcc700 R09: 00007f68e4dcc700 [ 42.032723] R10: 0000000000080000 R11: 0000000000000202 R12: 0000000000000000 [ 42.039961] R13: 00000000007efd4f R14: 00007f68e4dcc9c0 R15: 0000000000000000 [ 42.047357] Dumping ftrace buffer: [ 42.050917] (ftrace buffer empty) [ 42.054596] Kernel Offset: disabled [ 42.058203] Rebooting in 86400 seconds..