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-7,10.128.0.40' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 32.018044] refcount_t: underflow; use-after-free. [ 32.018862] ------------[ cut here ]------------ [ 32.019827] WARNING: CPU: 0 PID: 2999 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 32.021056] Kernel panic - not syncing: panic_on_warn set ... [ 32.021056] [ 32.022047] CPU: 0 PID: 2999 Comm: syzkaller620838 Not tainted 4.13.0-rc5+ #40 [ 32.023030] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.024248] Call Trace: [ 32.024607] dump_stack+0x194/0x257 [ 32.025098] ? arch_local_irq_restore+0x53/0x53 [ 32.025743] panic+0x1e4/0x417 [ 32.026177] ? __warn+0x1d9/0x1d9 [ 32.026670] ? show_regs_print_info+0x65/0x65 [ 32.027294] ? refcount_sub_and_test+0x167/0x1b0 [ 32.027929] __warn+0x1c4/0x1d9 [ 32.028398] ? refcount_sub_and_test+0x167/0x1b0 [ 32.029042] report_bug+0x211/0x2d0 [ 32.029536] fixup_bug+0x40/0x90 [ 32.030037] do_trap+0x260/0x390 [ 32.030500] do_error_trap+0x120/0x390 [ 32.031044] ? vprintk_emit+0x49b/0x590 [ 32.031580] ? do_trap+0x390/0x390 [ 32.032075] ? refcount_sub_and_test+0x167/0x1b0 [ 32.032740] ? vprintk_emit+0x3ea/0x590 [ 32.033280] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 32.033988] do_invalid_op+0x1b/0x20 [ 32.034487] invalid_op+0x1e/0x30 [ 32.034954] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 32.035691] RSP: 0018:ffff8801d052e928 EFLAGS: 00010282 [ 32.036428] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 32.037423] RDX: 0000000000000026 RSI: 1ffff1003a0a5ce5 RDI: ffffed003a0a5d19 [ 32.039687] RBP: ffff8801d052e9b8 R08: 0000000000000001 R09: 0000000000000000 [ 32.046928] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a0a5d26 [ 32.054170] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d2290a3c [ 32.061428] ? refcount_sub_and_test+0x167/0x1b0 [ 32.066155] ? refcount_inc+0x50/0x50 [ 32.069931] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 32.074658] ? sctp_association_free+0x2d0/0x930 [ 32.079380] ? sctp_do_sm+0x28e7/0x6d90 [ 32.083322] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 32.088040] ? sctp_close+0x3c6/0x980 [ 32.091806] ? inet_release+0xed/0x1c0 [ 32.095668] sctp_wfree+0x183/0x620 [ 32.099262] ? __sctp_write_space+0x910/0x910 [ 32.103725] skb_release_head_state+0x124/0x200 [ 32.108363] skb_release_all+0x15/0x60 [ 32.112219] consume_skb+0x153/0x490 [ 32.115896] ? sctp_chunk_put+0x99/0x420 [ 32.119924] ? pskb_carve+0x1db0/0x1db0 [ 32.123864] ? sctp_chunk_hold+0x20/0x20 [ 32.127894] ? refcount_sub_and_test+0x115/0x1b0 [ 32.132615] ? refcount_inc+0x50/0x50 [ 32.136381] ? mark_held_locks+0xaf/0x100 [ 32.140498] ? sctp_datamsg_put+0x456/0x560 [ 32.144793] sctp_chunk_put+0x29c/0x420 [ 32.148737] ? sctp_chunk_hold+0x20/0x20 [ 32.152766] ? sctp_transport_dst_confirm+0x50/0x50 [ 32.157768] sctp_chunk_free+0x53/0x60 [ 32.161623] __sctp_outq_teardown+0xc7d/0x15a0 [ 32.166171] ? bpf_prog_kallsyms_find+0xbd/0x440 [ 32.170912] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 32.175815] ? is_bpf_text_address+0x7b/0x120 [ 32.180277] ? lock_downgrade+0x990/0x990 [ 32.184393] ? lock_release+0xa40/0xa40 [ 32.188338] ? update_stack_state+0x700/0x700 [ 32.192800] ? print_usage_bug+0x480/0x480 [ 32.197009] ? is_bpf_text_address+0xa4/0x120 [ 32.201473] ? unwind_get_return_address+0x61/0xa0 [ 32.206371] ? __save_stack_trace+0x7e/0xd0 [ 32.210665] ? check_noncircular+0x20/0x20 [ 32.214872] ? print_usage_bug+0x480/0x480 [ 32.219074] ? save_stack_trace+0x16/0x20 [ 32.223187] ? save_trace+0x11f/0x350 [ 32.226965] ? lock_acquire+0x1d5/0x580 [ 32.230905] ? lock_acquire+0x1d5/0x580 [ 32.234845] ? lock_timer_base+0x1a3/0x2b0 [ 32.239049] ? find_held_lock+0x35/0x1d0 [ 32.243082] ? sock_def_wakeup+0x1f9/0x350 [ 32.247281] ? lock_downgrade+0x990/0x990 [ 32.251396] ? lock_release+0xa40/0xa40 [ 32.255340] sctp_outq_free+0x15/0x20 [ 32.259108] sctp_association_free+0x2d0/0x930 [ 32.263670] ? sctp_asconf_queue_teardown+0x700/0x700 [ 32.268825] ? sock_def_wakeup+0x222/0x350 [ 32.273028] ? sk_dst_check+0x560/0x560 [ 32.276969] ? sctp_association_put+0x74/0x2f0 [ 32.281516] ? sctp_association_hold+0x20/0x20 [ 32.286072] ? sctp_sm_lookup_event+0x95/0x3c0 [ 32.290623] sctp_do_sm+0x28e7/0x6d90 [ 32.294391] ? check_noncircular+0x20/0x20 [ 32.298599] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 32.304626] ? print_usage_bug+0x480/0x480 [ 32.308837] ? print_usage_bug+0x480/0x480 [ 32.313054] ? mark_held_locks+0xaf/0x100 [ 32.317172] ? retint_kernel+0x10/0x10 [ 32.321029] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 32.326013] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 32.330739] ? retint_kernel+0x10/0x10 [ 32.334620] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 32.339176] sctp_close+0x3c6/0x980 [ 32.342782] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 32.348021] ? unwind_get_return_address+0x61/0xa0 [ 32.352916] ? __save_stack_trace+0x7e/0xd0 [ 32.357211] ? check_noncircular+0x20/0x20 [ 32.361416] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 32.365880] ? ipv6_sock_mc_close+0x148/0x1a0 [ 32.370345] ? ipv6_sock_ac_drop+0x580/0x580 [ 32.374723] ? ip_mc_drop_socket+0x1ce/0x230 [ 32.379099] ? __fsnotify_parent+0xb4/0x3a0 [ 32.383391] inet_release+0xed/0x1c0 [ 32.387075] inet6_release+0x50/0x70 [ 32.390761] sock_release+0x8d/0x1e0 [ 32.394441] ? sock_release+0x1e0/0x1e0 [ 32.398380] sock_close+0x16/0x20 [ 32.401812] __fput+0x327/0x7e0 [ 32.405065] ? fput+0x140/0x140 [ 32.408314] ? do_raw_spin_trylock+0x190/0x190 [ 32.412864] ? check_same_owner+0x320/0x320 [ 32.417155] ____fput+0x15/0x20 [ 32.420402] task_work_run+0x18a/0x260 [ 32.424258] ? task_work_cancel+0x210/0x210 [ 32.428546] ? _raw_spin_unlock+0x22/0x30 [ 32.432661] ? switch_task_namespaces+0x87/0xc0 [ 32.437311] do_exit+0xa3a/0x1b10 [ 32.440741] ? __fd_install+0x2da/0x6a0 [ 32.444686] ? mm_update_next_owner+0x930/0x930 [ 32.449324] ? __lock_is_held+0xb6/0x140 [ 32.453363] ? __fd_install+0x2f7/0x6a0 [ 32.457309] ? get_unused_fd_flags+0x190/0x190 [ 32.461868] ? __might_sleep+0x95/0x190 [ 32.465819] ? kasan_check_read+0x11/0x20 [ 32.469935] ? _copy_to_user+0xa2/0xc0 [ 32.473793] ? fd_install+0x4d/0x60 [ 32.477387] ? SYSC_accept4+0x4ec/0x850 [ 32.481339] ? kernel_accept+0x2f0/0x2f0 [ 32.485368] ? __do_page_fault+0x51b/0xb60 [ 32.489572] ? lock_downgrade+0x990/0x990 [ 32.493700] ? down_read_trylock+0xdb/0x170 [ 32.497994] ? __handle_mm_fault+0x3810/0x3810 [ 32.502542] ? vmacache_find+0x61/0x270 [ 32.506491] do_group_exit+0x149/0x400 [ 32.510349] ? SyS_exit+0x30/0x30 [ 32.513770] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 32.518753] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 32.523480] SyS_exit_group+0x1d/0x20 [ 32.527250] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 32.531971] RIP: 0033:0x43e9d8 [ 32.535132] RSP: 002b:00007ffd9e368928 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 32.542803] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043e9d8 [ 32.550040] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 32.557275] RBP: 0000000000000086 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 32.564510] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401700 [ 32.571744] R13: 0000000000401790 R14: 0000000000000000 R15: 0000000000000000 [ 32.579133] Dumping ftrace buffer: [ 32.582678] (ftrace buffer empty) [ 32.586360] Kernel Offset: disabled [ 32.589962] Rebooting in 86400 seconds..