[....] 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. [ 28.878277] kauditd_printk_skb: 7 callbacks suppressed [ 28.878289] audit: type=1800 audit(1544992723.981:29): pid=5878 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 28.904770] audit: type=1800 audit(1544992723.981:30): pid=5878 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 32.066571] sshd (6017) used greatest stack depth: 15744 bytes left Warning: Permanently added '10.128.0.122' (ECDSA) to the list of known hosts. executing program [ 44.414340] ================================================================== [ 44.421997] BUG: KASAN: use-after-free in tipc_group_bc_cong+0x327/0x3f0 [ 44.428934] Read of size 2 at addr ffff8881d96bac74 by task syz-executor650/6037 [ 44.436453] [ 44.438087] CPU: 0 PID: 6037 Comm: syz-executor650 Not tainted 4.20.0-rc6+ #374 [ 44.445512] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.454850] Call Trace: [ 44.457423] dump_stack+0x244/0x39d [ 44.461044] ? dump_stack_print_info.cold.1+0x20/0x20 [ 44.466219] ? printk+0xa7/0xcf [ 44.469483] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 44.474232] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 44.479339] print_address_description.cold.7+0x9/0x1ff [ 44.484689] kasan_report.cold.8+0x242/0x309 [ 44.489087] ? tipc_group_bc_cong+0x327/0x3f0 [ 44.493569] __asan_report_load2_noabort+0x14/0x20 [ 44.498536] tipc_group_bc_cong+0x327/0x3f0 [ 44.503024] ? _raw_spin_unlock_irqrestore+0x6d/0xd0 [ 44.508122] ? tipc_group_cong+0x5d0/0x5d0 [ 44.512345] ? remove_wait_queue+0x1a6/0x360 [ 44.516741] ? add_wait_queue+0x2b0/0x2b0 [ 44.520878] ? __local_bh_enable_ip+0x160/0x260 [ 44.525535] tipc_send_group_bcast+0x50a/0xd90 [ 44.530112] ? tipc_sk_sock_err.isra.61+0x2f0/0x2f0 [ 44.535116] ? __init_waitqueue_head+0x150/0x150 [ 44.539864] ? refill_pi_state_cache.part.8+0x310/0x310 [ 44.545232] ? mark_held_locks+0x130/0x130 [ 44.549447] ? futex_wait_setup+0x266/0x3e0 [ 44.553757] ? futex_wake+0x760/0x760 [ 44.557541] ? print_usage_bug+0xc0/0xc0 [ 44.561586] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 44.566763] __tipc_sendmsg+0xeec/0x1d40 [ 44.570807] ? futex_wait+0x5ec/0xa50 [ 44.574600] ? tipc_sendmcast+0xf50/0xf50 [ 44.578740] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 44.583926] ? zap_class+0x640/0x640 [ 44.587638] ? print_usage_bug+0xc0/0xc0 [ 44.591703] ? find_held_lock+0x36/0x1c0 [ 44.595751] ? mark_held_locks+0xc7/0x130 [ 44.599892] ? __local_bh_enable_ip+0x160/0x260 [ 44.604668] ? __local_bh_enable_ip+0x160/0x260 [ 44.609330] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 44.613906] ? trace_hardirqs_on+0xbd/0x310 [ 44.618215] ? lock_release+0xa00/0xa00 [ 44.622173] ? lock_sock_nested+0xe2/0x120 [ 44.626396] ? trace_hardirqs_off_caller+0x310/0x310 [ 44.631486] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 44.637010] ? check_preemption_disabled+0x48/0x280 [ 44.642019] ? lock_sock_nested+0x9a/0x120 [ 44.646246] ? lock_sock_nested+0x9a/0x120 [ 44.650469] ? __local_bh_enable_ip+0x160/0x260 [ 44.655128] tipc_sendmsg+0x50/0x70 [ 44.658750] ? __tipc_sendmsg+0x1d40/0x1d40 [ 44.663071] sock_sendmsg+0xd5/0x120 [ 44.666772] ___sys_sendmsg+0x7fd/0x930 [ 44.670732] ? find_held_lock+0x36/0x1c0 [ 44.674782] ? copy_msghdr_from_user+0x580/0x580 [ 44.679521] ? __fd_install+0x2b5/0x8f0 [ 44.683483] ? check_preemption_disabled+0x48/0x280 [ 44.688487] ? __fget_light+0x2e9/0x430 [ 44.692448] ? fget_raw+0x20/0x20 [ 44.695888] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 44.701411] ? __fd_install+0x2f9/0x8f0 [ 44.705382] ? get_unused_fd_flags+0x1a0/0x1a0 [ 44.709968] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 44.715492] ? sockfd_lookup_light+0xc5/0x160 [ 44.719976] __sys_sendmsg+0x11d/0x280 [ 44.723852] ? __ia32_sys_shutdown+0x80/0x80 [ 44.728248] ? __x64_sys_futex+0x47f/0x6a0 [ 44.732470] ? do_syscall_64+0x9a/0x820 [ 44.736427] ? do_syscall_64+0x9a/0x820 [ 44.740404] ? trace_hardirqs_off_caller+0x310/0x310 [ 44.745493] __x64_sys_sendmsg+0x78/0xb0 [ 44.749638] do_syscall_64+0x1b9/0x820 [ 44.753517] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 44.758872] ? syscall_return_slowpath+0x5e0/0x5e0 [ 44.763787] ? trace_hardirqs_on_caller+0x310/0x310 [ 44.768930] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 44.773934] ? post_copy_siginfo_from_user.isra.25.part.26+0x250/0x250 [ 44.780583] ? __switch_to_asm+0x40/0x70 [ 44.784630] ? __switch_to_asm+0x34/0x70 [ 44.788677] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 44.793516] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 44.798692] RIP: 0033:0x446389 [ 44.801879] Code: e8 2c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 44.820765] RSP: 002b:00007ff2dc03bdb8 EFLAGS: 00000297 ORIG_RAX: 000000000000002e [ 44.828472] RAX: ffffffffffffffda RBX: 00000000006dac38 RCX: 0000000000446389 [ 44.835726] RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000005 [ 44.842981] RBP: 00000000006dac30 R08: 0000000000000000 R09: 0000000000000000 [ 44.850444] R10: 0000000000000000 R11: 0000000000000297 R12: 00000000006dac3c [ 44.857703] R13: 00007ffdf26cd82f R14: 00007ff2dc03c9c0 R15: 00000000006dad2c [ 44.865004] [ 44.866634] Allocated by task 6038: [ 44.870250] save_stack+0x43/0xd0 [ 44.873695] kasan_kmalloc+0xc7/0xe0 [ 44.877396] kmem_cache_alloc_trace+0x152/0x750 [ 44.882061] tipc_group_create+0x152/0xa70 [ 44.886278] tipc_setsockopt+0x2d1/0xd70 [ 44.890328] __sys_setsockopt+0x1ba/0x3c0 [ 44.894459] __x64_sys_setsockopt+0xbe/0x150 [ 44.898997] do_syscall_64+0x1b9/0x820 [ 44.902869] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 44.908031] [ 44.909675] Freed by task 6038: [ 44.912936] save_stack+0x43/0xd0 [ 44.916430] __kasan_slab_free+0x102/0x150 [ 44.920686] kasan_slab_free+0xe/0x10 [ 44.924483] kfree+0xcf/0x230 [ 44.927575] tipc_group_delete+0x2e4/0x3f0 [ 44.931926] tipc_sk_leave+0x113/0x220 [ 44.935798] tipc_setsockopt+0x97d/0xd70 [ 44.939870] __sys_setsockopt+0x1ba/0x3c0 [ 44.944125] __x64_sys_setsockopt+0xbe/0x150 [ 44.948517] do_syscall_64+0x1b9/0x820 [ 44.952386] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 44.957550] [ 44.959174] The buggy address belongs to the object at ffff8881d96bac00 [ 44.959174] which belongs to the cache kmalloc-192 of size 192 [ 44.971812] The buggy address is located 116 bytes inside of [ 44.971812] 192-byte region [ffff8881d96bac00, ffff8881d96bacc0) [ 44.983683] The buggy address belongs to the page: [ 44.988609] page:ffffea000765ae80 count:1 mapcount:0 mapping:ffff8881da800040 index:0xffff8881d96baf00 [ 44.998042] flags: 0x2fffc0000000200(slab) [ 45.002265] raw: 02fffc0000000200 ffffea000765af48 ffffea000765ad08 ffff8881da800040 [ 45.010140] raw: ffff8881d96baf00 ffff8881d96ba000 0000000100000001 0000000000000000 [ 45.018118] page dumped because: kasan: bad access detected [ 45.023809] [ 45.025415] Memory state around the buggy address: [ 45.030322] ffff8881d96bab00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.037789] ffff8881d96bab80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 45.045235] >ffff8881d96bac00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.052573] ^ [ 45.059563] ffff8881d96bac80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 45.066910] ffff8881d96bad00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 45.074250] ================================================================== [ 45.081589] Disabling lock debugging due to kernel taint [ 45.087723] Kernel panic - not syncing: panic_on_warn set ... [ 45.093618] CPU: 0 PID: 6037 Comm: syz-executor650 Tainted: G B 4.20.0-rc6+ #374 [ 45.102509] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.111847] Call Trace: [ 45.114533] dump_stack+0x244/0x39d [ 45.118151] ? dump_stack_print_info.cold.1+0x20/0x20 [ 45.123326] panic+0x2ad/0x55c [ 45.126506] ? add_taint.cold.5+0x16/0x16 [ 45.130647] ? preempt_schedule+0x4d/0x60 [ 45.134831] ? ___preempt_schedule+0x16/0x18 [ 45.139356] ? trace_hardirqs_on+0xb4/0x310 [ 45.143662] kasan_end_report+0x47/0x4f [ 45.147748] kasan_report.cold.8+0x76/0x309 [ 45.152063] ? tipc_group_bc_cong+0x327/0x3f0 [ 45.156541] __asan_report_load2_noabort+0x14/0x20 [ 45.161461] tipc_group_bc_cong+0x327/0x3f0 [ 45.165780] ? _raw_spin_unlock_irqrestore+0x6d/0xd0 [ 45.170875] ? tipc_group_cong+0x5d0/0x5d0 [ 45.175092] ? remove_wait_queue+0x1a6/0x360 [ 45.179586] ? add_wait_queue+0x2b0/0x2b0 [ 45.183828] ? __local_bh_enable_ip+0x160/0x260 [ 45.188641] tipc_send_group_bcast+0x50a/0xd90 [ 45.193235] ? tipc_sk_sock_err.isra.61+0x2f0/0x2f0 [ 45.198240] ? __init_waitqueue_head+0x150/0x150 [ 45.202978] ? refill_pi_state_cache.part.8+0x310/0x310 [ 45.208344] ? mark_held_locks+0x130/0x130 [ 45.212716] ? futex_wait_setup+0x266/0x3e0 [ 45.217028] ? futex_wake+0x760/0x760 [ 45.220825] ? print_usage_bug+0xc0/0xc0 [ 45.224872] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 45.230050] __tipc_sendmsg+0xeec/0x1d40 [ 45.234092] ? futex_wait+0x5ec/0xa50 [ 45.237871] ? tipc_sendmcast+0xf50/0xf50 [ 45.241996] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 45.247167] ? zap_class+0x640/0x640 [ 45.250865] ? print_usage_bug+0xc0/0xc0 [ 45.254925] ? find_held_lock+0x36/0x1c0 [ 45.258974] ? mark_held_locks+0xc7/0x130 [ 45.263151] ? __local_bh_enable_ip+0x160/0x260 [ 45.267801] ? __local_bh_enable_ip+0x160/0x260 [ 45.272451] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 45.277012] ? trace_hardirqs_on+0xbd/0x310 [ 45.281318] ? lock_release+0xa00/0xa00 [ 45.285271] ? lock_sock_nested+0xe2/0x120 [ 45.289487] ? trace_hardirqs_off_caller+0x310/0x310 [ 45.294577] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 45.300093] ? check_preemption_disabled+0x48/0x280 [ 45.305209] ? lock_sock_nested+0x9a/0x120 [ 45.309425] ? lock_sock_nested+0x9a/0x120 [ 45.313651] ? __local_bh_enable_ip+0x160/0x260 [ 45.318311] tipc_sendmsg+0x50/0x70 [ 45.321927] ? __tipc_sendmsg+0x1d40/0x1d40 [ 45.326233] sock_sendmsg+0xd5/0x120 [ 45.329930] ___sys_sendmsg+0x7fd/0x930 [ 45.333887] ? find_held_lock+0x36/0x1c0 [ 45.337932] ? copy_msghdr_from_user+0x580/0x580 [ 45.342689] ? __fd_install+0x2b5/0x8f0 [ 45.346666] ? check_preemption_disabled+0x48/0x280 [ 45.351699] ? __fget_light+0x2e9/0x430 [ 45.355651] ? fget_raw+0x20/0x20 [ 45.359097] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 45.364618] ? __fd_install+0x2f9/0x8f0 [ 45.368573] ? get_unused_fd_flags+0x1a0/0x1a0 [ 45.373264] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 45.378825] ? sockfd_lookup_light+0xc5/0x160 [ 45.383305] __sys_sendmsg+0x11d/0x280 [ 45.387181] ? __ia32_sys_shutdown+0x80/0x80 [ 45.391574] ? __x64_sys_futex+0x47f/0x6a0 [ 45.395791] ? do_syscall_64+0x9a/0x820 [ 45.399750] ? do_syscall_64+0x9a/0x820 [ 45.403719] ? trace_hardirqs_off_caller+0x310/0x310 [ 45.408815] __x64_sys_sendmsg+0x78/0xb0 [ 45.412854] do_syscall_64+0x1b9/0x820 [ 45.416737] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 45.422082] ? syscall_return_slowpath+0x5e0/0x5e0 [ 45.426995] ? trace_hardirqs_on_caller+0x310/0x310 [ 45.431998] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 45.437069] ? post_copy_siginfo_from_user.isra.25.part.26+0x250/0x250 [ 45.443726] ? __switch_to_asm+0x40/0x70 [ 45.447784] ? __switch_to_asm+0x34/0x70 [ 45.451848] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 45.456681] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 45.461874] RIP: 0033:0x446389 [ 45.465069] Code: e8 2c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 45.484101] RSP: 002b:00007ff2dc03bdb8 EFLAGS: 00000297 ORIG_RAX: 000000000000002e [ 45.491823] RAX: ffffffffffffffda RBX: 00000000006dac38 RCX: 0000000000446389 [ 45.499077] RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000005 [ 45.506350] RBP: 00000000006dac30 R08: 0000000000000000 R09: 0000000000000000 [ 45.513723] R10: 0000000000000000 R11: 0000000000000297 R12: 00000000006dac3c [ 45.521009] R13: 00007ffdf26cd82f R14: 00007ff2dc03c9c0 R15: 00000000006dad2c [ 45.529245] Kernel Offset: disabled [ 45.532867] Rebooting in 86400 seconds..