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-386-3,10.128.15.221' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 31.240742] refcount_t: underflow; use-after-free. [ 31.246187] ------------[ cut here ]------------ [ 31.250983] WARNING: CPU: 0 PID: 2986 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 31.260110] Kernel panic - not syncing: panic_on_warn set ... [ 31.260110] [ 31.267514] CPU: 1 PID: 2986 Comm: syzkaller036010 Not tainted 4.14.0-rc2+ #12 [ 31.274850] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.284180] Call Trace: [ 31.286751] dump_stack+0x194/0x257 [ 31.290358] ? arch_local_irq_restore+0x53/0x53 [ 31.295018] panic+0x1e4/0x417 [ 31.298186] ? __warn+0x1d9/0x1d9 [ 31.301612] ? show_regs_print_info+0x65/0x65 [ 31.306084] ? retint_kernel+0x10/0x10 [ 31.309955] ? refcount_sub_and_test+0x167/0x1b0 [ 31.314685] __warn+0x1c4/0x1d9 [ 31.317936] ? refcount_sub_and_test+0x169/0x1b0 [ 31.322661] ? refcount_sub_and_test+0x167/0x1b0 [ 31.327391] report_bug+0x211/0x2d0 [ 31.330997] fixup_bug+0x40/0x90 [ 31.334337] do_trap+0x260/0x390 [ 31.337688] do_error_trap+0x120/0x390 [ 31.341547] ? vprintk_emit+0x49b/0x590 [ 31.345499] ? do_trap+0x390/0x390 [ 31.349015] ? refcount_sub_and_test+0x167/0x1b0 [ 31.353742] ? vprintk_emit+0x3ea/0x590 [ 31.357700] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.362525] do_invalid_op+0x1b/0x20 [ 31.366213] invalid_op+0x18/0x20 [ 31.369640] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 31.374977] RSP: 0018:ffff8801ce5566c8 EFLAGS: 00010282 [ 31.380315] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 31.387556] RDX: 0000000000000026 RSI: 1ffff10039caac99 RDI: ffffed0039caaccd [ 31.394798] RBP: ffff8801ce556758 R08: ffff8801ce555db8 R09: 0000000000000000 [ 31.402040] R10: ffff8801ceafe280 R11: 0000000000000000 R12: 1ffff10039caacda [ 31.409281] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d28fcae4 [ 31.416553] ? refcount_sub_and_test+0x167/0x1b0 [ 31.421281] ? refcount_inc+0x50/0x50 [ 31.425053] ? add_lock_to_list.isra.33+0x1ff/0x4f0 [ 31.430062] sctp_wfree+0x183/0x620 [ 31.433660] ? __sctp_write_space+0x910/0x910 [ 31.438131] skb_release_head_state+0x124/0x200 [ 31.442775] skb_release_all+0x15/0x60 [ 31.446646] consume_skb+0x153/0x490 [ 31.450335] ? alloc_skb_with_frags+0x710/0x710 [ 31.454984] ? refcount_sub_and_test+0x115/0x1b0 [ 31.459716] ? refcount_inc+0x50/0x50 [ 31.463490] ? unwind_get_return_address+0x61/0xa0 [ 31.468405] sctp_chunk_put+0x29c/0x420 [ 31.472357] ? sctp_chunk_hold+0x20/0x20 [ 31.476392] ? refcount_sub_and_test+0x115/0x1b0 [ 31.481119] ? refcount_sub_and_test+0x115/0x1b0 [ 31.485847] ? refcount_inc+0x50/0x50 [ 31.489626] ? __lock_acquire+0x732/0x4620 [ 31.493842] sctp_datamsg_put+0x22d/0x560 [ 31.497971] ? sctp_transport_dst_confirm+0x50/0x50 [ 31.502979] sctp_chunk_free+0x46/0x60 [ 31.506853] __sctp_outq_teardown+0xc7d/0x15a0 [ 31.511408] ? inet6_release+0x50/0x70 [ 31.515279] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 31.520182] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 31.525170] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 31.530159] ? unwind_dump+0x4c0/0x4c0 [ 31.534021] ? unwind_dump+0x4c0/0x4c0 [ 31.537896] ? copy_trace+0x1d0/0x1d0 [ 31.541674] ? check_noncircular+0x20/0x20 [ 31.545880] ? check_noncircular+0x20/0x20 [ 31.550087] ? unwind_get_return_address+0x61/0xa0 [ 31.554998] ? __save_stack_trace+0x61/0xd0 [ 31.559305] ? check_noncircular+0x20/0x20 [ 31.563516] ? print_usage_bug+0x480/0x480 [ 31.567743] ? find_held_lock+0x39/0x1d0 [ 31.571792] ? lock_downgrade+0x990/0x990 [ 31.575931] ? sk_dst_check+0x560/0x560 [ 31.579880] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.584880] ? lock_release+0xd70/0xd70 [ 31.588835] sctp_outq_free+0x15/0x20 [ 31.592607] sctp_association_free+0x2d0/0x930 [ 31.597164] ? sctp_asconf_queue_teardown+0x700/0x700 [ 31.602329] ? sock_def_wakeup+0x222/0x350 [ 31.606537] ? sk_dst_check+0x560/0x560 [ 31.610488] ? sctp_association_put+0x74/0x2f0 [ 31.615044] ? sctp_association_hold+0x20/0x20 [ 31.619600] ? unwind_dump+0x4c0/0x4c0 [ 31.623470] sctp_do_sm+0x28e7/0x6dd0 [ 31.627259] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 31.633295] ? print_usage_bug+0x480/0x480 [ 31.637512] ? __lock_acquire+0x20fd/0x4620 [ 31.641811] ? print_usage_bug+0x480/0x480 [ 31.646021] ? find_held_lock+0x39/0x1d0 [ 31.650067] ? lock_downgrade+0x990/0x990 [ 31.654194] ? skb_dequeue+0x22/0x180 [ 31.657990] ? do_raw_spin_trylock+0x190/0x190 [ 31.662553] ? mark_held_locks+0xb2/0x100 [ 31.666685] ? trace_hardirqs_on+0xd/0x10 [ 31.670815] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 31.675376] sctp_close+0x3c6/0x980 [ 31.678986] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 31.684237] ? unwind_get_return_address+0x61/0xa0 [ 31.689143] ? check_noncircular+0x20/0x20 [ 31.693357] ? depot_save_stack+0x3b5/0x490 [ 31.697666] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 31.702141] ? ipv6_sock_mc_close+0x148/0x1a0 [ 31.706614] ? ip_mc_drop_socket+0x1ce/0x230 [ 31.710996] ? __fsnotify_parent+0xb4/0x3a0 [ 31.715294] inet_release+0xed/0x1c0 [ 31.718985] inet6_release+0x50/0x70 [ 31.722675] sock_release+0x8d/0x1e0 [ 31.726360] ? sock_release+0x1e0/0x1e0 [ 31.730305] sock_close+0x16/0x20 [ 31.733730] __fput+0x333/0x7f0 [ 31.736989] ? fput+0x140/0x140 [ 31.740245] ? _raw_spin_unlock_irq+0x27/0x70 [ 31.744721] ____fput+0x15/0x20 [ 31.747978] task_work_run+0x199/0x270 [ 31.751850] ? task_work_cancel+0x210/0x210 [ 31.756147] ? _raw_spin_unlock+0x22/0x30 [ 31.760269] ? switch_task_namespaces+0x87/0xc0 [ 31.764919] do_exit+0x9d2/0x1af0 [ 31.768346] ? get_unused_fd_flags+0x190/0x190 [ 31.772909] ? mm_update_next_owner+0x930/0x930 [ 31.777557] ? __lock_is_held+0xbc/0x140 [ 31.781623] ? __fd_install+0x2f7/0x6a0 [ 31.785584] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 31.790319] ? get_unused_fd_flags+0x190/0x190 [ 31.794894] ? copy_user_generic_unrolled+0x89/0xc0 [ 31.799890] ? _copy_to_user+0xa2/0xc0 [ 31.803757] ? fd_install+0x4d/0x60 [ 31.807359] ? SYSC_accept4+0x4f2/0x850 [ 31.811313] ? kernel_accept+0x2f0/0x2f0 [ 31.815371] do_group_exit+0x149/0x400 [ 31.819231] ? __handle_mm_fault+0x39c0/0x39c0 [ 31.823788] ? vmacache_find+0x5f/0x280 [ 31.827736] ? SyS_exit+0x30/0x30 [ 31.831166] ? do_fast_syscall_32+0x158/0xf05 [ 31.835636] ? do_group_exit+0x400/0x400 [ 31.839672] SyS_exit_group+0x1d/0x20 [ 31.843446] do_fast_syscall_32+0x3f2/0xf05 [ 31.847756] ? do_int80_syscall_32+0x940/0x940 [ 31.852314] ? kasan_check_read+0x11/0x20 [ 31.856437] ? syscall_return_slowpath+0x510/0x510 [ 31.861341] ? SyS_rt_sigaction+0x94/0x1b0 [ 31.865557] ? sysret32_from_system_call+0x5/0x3b [ 31.870383] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.875207] entry_SYSENTER_compat+0x51/0x60 [ 31.879603] RIP: 0023:0xf7fdfc79 [ 31.882940] RSP: 002b:00000000fffe625c EFLAGS: 00000296 ORIG_RAX: 00000000000000fc [ 31.890622] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000080ec298 [ 31.897865] RDX: 0000000000000000 RSI: 00000000080d6578 RDI: 00000000080ec2a0 [ 31.905108] RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 [ 31.912364] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 31.919607] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 31.927051] Dumping ftrace buffer: [ 31.930632] (ftrace buffer empty) [ 31.934321] Kernel Offset: disabled [ 31.937934] Rebooting in 86400 seconds..