[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.973555] audit: type=1800 audit(1546349677.585:25): pid=7824 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 39.006505] audit: type=1800 audit(1546349677.585:26): pid=7824 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 39.044852] audit: type=1800 audit(1546349677.585:27): pid=7824 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] 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 '10.128.0.73' (ECDSA) to the list of known hosts. syzkaller login: [ 49.800461] IPVS: ftp: loaded support on port[0] = 21 executing program [ 49.878285] L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html for details. [ 49.900189] ================================================================== [ 49.907637] BUG: KASAN: slab-out-of-bounds in kvm_clear_dirty_log_protect+0x8cf/0x970 [ 49.915587] Read of size 8 at addr ffff8880a13e5810 by task syz-executor650/7975 [ 49.923100] [ 49.924710] CPU: 0 PID: 7975 Comm: syz-executor650 Not tainted 4.20.0+ #3 [ 49.931647] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.940981] Call Trace: [ 49.943556] dump_stack+0x1db/0x2d0 [ 49.947194] ? dump_stack_print_info.cold+0x20/0x20 [ 49.952198] ? kvm_clear_dirty_log_protect+0x8cf/0x970 [ 49.957460] print_address_description.cold+0x7c/0x20d [ 49.962716] ? kvm_clear_dirty_log_protect+0x8cf/0x970 [ 49.967990] ? kvm_clear_dirty_log_protect+0x8cf/0x970 [ 49.973247] kasan_report.cold+0x1b/0x40 [ 49.977291] ? kvm_clear_dirty_log_protect+0x8cf/0x970 [ 49.982553] __asan_report_load8_noabort+0x14/0x20 [ 49.987470] kvm_clear_dirty_log_protect+0x8cf/0x970 [ 49.992560] ? vcpu_stat_get_per_vm_open+0x40/0x40 [ 49.997495] ? lock_downgrade+0x910/0x910 [ 50.001624] ? lock_release+0xc40/0xc40 [ 50.005601] kvm_vm_ioctl_clear_dirty_log+0xff/0x260 [ 50.010693] ? kvm_vm_ioctl_get_dirty_log+0x260/0x260 [ 50.015883] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 50.021415] ? _copy_from_user+0xdd/0x150 [ 50.025544] kvm_vm_ioctl+0xc19/0x1fe0 [ 50.029414] ? lock_downgrade+0x910/0x910 [ 50.033560] ? kasan_check_read+0x11/0x20 [ 50.037689] ? kvm_unregister_device_ops+0x70/0x70 [ 50.042606] ? rcu_softirq_qs+0x20/0x20 [ 50.046571] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 50.052096] ? __fd_install+0x2e4/0x8c0 [ 50.056060] ? lockdep_hardirqs_on+0x415/0x5d0 [ 50.060621] ? get_unused_fd_flags+0x1a0/0x1a0 [ 50.065196] ? kvm_uevent_notify_change.part.0+0x2de/0x440 [ 50.070807] ? trace_hardirqs_off_caller+0x300/0x300 [ 50.075941] ? __kasan_slab_free+0x119/0x150 [ 50.080333] ? kvm_uevent_notify_change.part.0+0x2de/0x440 [ 50.085939] ? fd_install+0x4d/0x60 [ 50.089553] ? kvm_dev_ioctl+0x10e/0x1a60 [ 50.093703] ? kvm_debugfs_release+0x90/0x90 [ 50.098118] ? __handle_mm_fault+0x955/0x5690 [ 50.102613] ? add_lock_to_list.isra.0+0x450/0x450 [ 50.107544] ? vmf_insert_mixed_mkwrite+0x40/0x40 [ 50.112378] ? check_preemption_disabled+0x48/0x290 [ 50.117388] ? __do_page_fault+0x610/0xd60 [ 50.121803] ? find_held_lock+0x35/0x120 [ 50.125852] ? __do_page_fault+0x610/0xd60 [ 50.130073] ? kvm_unregister_device_ops+0x70/0x70 [ 50.134990] do_vfs_ioctl+0x107b/0x17d0 [ 50.138950] ? rcu_read_unlock_special+0x380/0x380 [ 50.143863] ? ioctl_preallocate+0x2f0/0x2f0 [ 50.148256] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 50.153775] ? __fget_light+0x2db/0x420 [ 50.157733] ? fget_raw+0x20/0x20 [ 50.161184] ? up_read_non_owner+0x100/0x100 [ 50.165602] ? do_syscall_64+0x8c/0x800 [ 50.169559] ? do_syscall_64+0x8c/0x800 [ 50.173517] ? lockdep_hardirqs_on+0x415/0x5d0 [ 50.178091] ? security_file_ioctl+0x93/0xc0 [ 50.182480] ksys_ioctl+0xab/0xd0 [ 50.185914] __x64_sys_ioctl+0x73/0xb0 [ 50.189795] do_syscall_64+0x1a3/0x800 [ 50.193666] ? syscall_return_slowpath+0x5f0/0x5f0 [ 50.198595] ? prepare_exit_to_usermode+0x232/0x3b0 [ 50.203631] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 50.208460] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 50.213658] RIP: 0033:0x440b09 [ 50.216856] Code: 23 02 00 85 c0 b8 00 00 00 00 48 0f 44 c3 5b c3 90 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 0b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 50.235769] RSP: 002b:00000000007dff68 EFLAGS: 00000217 ORIG_RAX: 0000000000000010 [ 50.243459] RAX: ffffffffffffffda RBX: 00000000004a28d8 RCX: 0000000000440b09 [ 50.250708] RDX: 0000000020000080 RSI: 00000000c018aec0 RDI: 0000000000000004 [ 50.258157] RBP: 00000000004a28d8 R08: 0000000120080522 R09: 0000000120080522 [ 50.265404] R10: 0000000120080522 R11: 0000000000000217 R12: 00000000004022a0 [ 50.272701] R13: 0000000000402330 R14: 0000000000000000 R15: 0000000000000000 [ 50.279974] [ 50.281599] Allocated by task 7975: [ 50.285210] save_stack+0x45/0xd0 [ 50.288657] kasan_kmalloc+0xcf/0xe0 [ 50.292345] __kmalloc_node+0x4e/0x70 [ 50.296126] kvmalloc_node+0x68/0x100 [ 50.299909] __kvm_set_memory_region+0x1da1/0x2c40 [ 50.304840] kvm_set_memory_region+0x2f/0x60 [ 50.309246] kvm_vm_ioctl+0xafa/0x1fe0 [ 50.313114] do_vfs_ioctl+0x107b/0x17d0 [ 50.317068] ksys_ioctl+0xab/0xd0 [ 50.320519] __x64_sys_ioctl+0x73/0xb0 [ 50.324426] do_syscall_64+0x1a3/0x800 [ 50.328294] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 50.333473] [ 50.335100] Freed by task 4309: [ 50.338361] save_stack+0x45/0xd0 [ 50.341794] __kasan_slab_free+0x102/0x150 [ 50.346046] kasan_slab_free+0xe/0x10 [ 50.349835] kfree+0xcf/0x230 [ 50.352927] single_release+0x95/0xc0 [ 50.356712] __fput+0x3c5/0xb10 [ 50.359981] ____fput+0x16/0x20 [ 50.363265] task_work_run+0x1f4/0x2b0 [ 50.367153] exit_to_usermode_loop+0x32a/0x3b0 [ 50.371720] do_syscall_64+0x696/0x800 [ 50.375590] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 50.380754] [ 50.382367] The buggy address belongs to the object at ffff8880a13e5800 [ 50.382367] which belongs to the cache kmalloc-32 of size 32 [ 50.394835] The buggy address is located 16 bytes inside of [ 50.394835] 32-byte region [ffff8880a13e5800, ffff8880a13e5820) [ 50.406510] The buggy address belongs to the page: [ 50.411418] page:ffffea000284f940 count:1 mapcount:0 mapping:ffff88812c3f01c0 index:0xffff8880a13e5fc1 [ 50.420844] flags: 0x1fffc0000000200(slab) [ 50.425063] raw: 01fffc0000000200 ffffea00027e3c48 ffff88812c3f1238 ffff88812c3f01c0 [ 50.432939] raw: ffff8880a13e5fc1 ffff8880a13e5000 0000000100000033 0000000000000000 [ 50.440811] page dumped because: kasan: bad access detected [ 50.446516] [ 50.448120] Memory state around the buggy address: [ 50.453027] ffff8880a13e5700: 00 00 fc fc fc fc fc fc 00 00 fc fc fc fc fc fc [ 50.460366] ffff8880a13e5780: 00 00 fc fc fc fc fc fc fb fb fb fb fc fc fc fc [ 50.467707] >ffff8880a13e5800: 00 00 fc fc fc fc fc fc fb fb fb fb fc fc fc fc [ 50.475041] ^ [ 50.478908] ffff8880a13e5880: 00 00 fc fc fc fc fc fc 00 00 fc fc fc fc fc fc [ 50.486246] ffff8880a13e5900: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc [ 50.493586] ================================================================== [ 50.500921] Disabling lock debugging due to kernel taint [ 50.506453] Kernel panic - not syncing: panic_on_warn set ... [ 50.512349] CPU: 0 PID: 7975 Comm: syz-executor650 Tainted: G B 4.20.0+ #3 [ 50.520653] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.529989] Call Trace: [ 50.532561] dump_stack+0x1db/0x2d0 [ 50.536169] ? dump_stack_print_info.cold+0x20/0x20 [ 50.541171] panic+0x2cb/0x589 [ 50.544341] ? add_taint.cold+0x16/0x16 [ 50.548300] ? trace_hardirqs_on+0xb4/0x310 [ 50.552600] ? trace_hardirqs_on+0xb4/0x310 [ 50.556923] ? kvm_clear_dirty_log_protect+0x8cf/0x970 [ 50.562211] end_report+0x47/0x4f [ 50.565673] ? kvm_clear_dirty_log_protect+0x8cf/0x970 [ 50.570928] kasan_report.cold+0xe/0x40 [ 50.574880] ? kvm_clear_dirty_log_protect+0x8cf/0x970 [ 50.580134] __asan_report_load8_noabort+0x14/0x20 [ 50.585043] kvm_clear_dirty_log_protect+0x8cf/0x970 [ 50.590129] ? vcpu_stat_get_per_vm_open+0x40/0x40 [ 50.595043] ? lock_downgrade+0x910/0x910 [ 50.599184] ? lock_release+0xc40/0xc40 [ 50.603158] kvm_vm_ioctl_clear_dirty_log+0xff/0x260 [ 50.608243] ? kvm_vm_ioctl_get_dirty_log+0x260/0x260 [ 50.613426] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 50.618947] ? _copy_from_user+0xdd/0x150 [ 50.623075] kvm_vm_ioctl+0xc19/0x1fe0 [ 50.626945] ? lock_downgrade+0x910/0x910 [ 50.631073] ? kasan_check_read+0x11/0x20 [ 50.635205] ? kvm_unregister_device_ops+0x70/0x70 [ 50.640131] ? rcu_softirq_qs+0x20/0x20 [ 50.644113] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 50.649660] ? __fd_install+0x2e4/0x8c0 [ 50.653614] ? lockdep_hardirqs_on+0x415/0x5d0 [ 50.658187] ? get_unused_fd_flags+0x1a0/0x1a0 [ 50.662765] ? kvm_uevent_notify_change.part.0+0x2de/0x440 [ 50.668369] ? trace_hardirqs_off_caller+0x300/0x300 [ 50.673451] ? __kasan_slab_free+0x119/0x150 [ 50.677847] ? kvm_uevent_notify_change.part.0+0x2de/0x440 [ 50.683462] ? fd_install+0x4d/0x60 [ 50.687090] ? kvm_dev_ioctl+0x10e/0x1a60 [ 50.691224] ? kvm_debugfs_release+0x90/0x90 [ 50.695615] ? __handle_mm_fault+0x955/0x5690 [ 50.700094] ? add_lock_to_list.isra.0+0x450/0x450 [ 50.705003] ? vmf_insert_mixed_mkwrite+0x40/0x40 [ 50.709832] ? check_preemption_disabled+0x48/0x290 [ 50.714837] ? __do_page_fault+0x610/0xd60 [ 50.719056] ? find_held_lock+0x35/0x120 [ 50.723102] ? __do_page_fault+0x610/0xd60 [ 50.727320] ? kvm_unregister_device_ops+0x70/0x70 [ 50.732229] do_vfs_ioctl+0x107b/0x17d0 [ 50.736184] ? rcu_read_unlock_special+0x380/0x380 [ 50.741102] ? ioctl_preallocate+0x2f0/0x2f0 [ 50.745513] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 50.751033] ? __fget_light+0x2db/0x420 [ 50.755002] ? fget_raw+0x20/0x20 [ 50.758439] ? up_read_non_owner+0x100/0x100 [ 50.762846] ? do_syscall_64+0x8c/0x800 [ 50.766805] ? do_syscall_64+0x8c/0x800 [ 50.770767] ? lockdep_hardirqs_on+0x415/0x5d0 [ 50.775331] ? security_file_ioctl+0x93/0xc0 [ 50.779736] ksys_ioctl+0xab/0xd0 [ 50.783167] __x64_sys_ioctl+0x73/0xb0 [ 50.787050] do_syscall_64+0x1a3/0x800 [ 50.790919] ? syscall_return_slowpath+0x5f0/0x5f0 [ 50.795843] ? prepare_exit_to_usermode+0x232/0x3b0 [ 50.800844] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 50.805669] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 50.810868] RIP: 0033:0x440b09 [ 50.814060] Code: 23 02 00 85 c0 b8 00 00 00 00 48 0f 44 c3 5b c3 90 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 0b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 50.832940] RSP: 002b:00000000007dff68 EFLAGS: 00000217 ORIG_RAX: 0000000000000010 [ 50.840625] RAX: ffffffffffffffda RBX: 00000000004a28d8 RCX: 0000000000440b09 [ 50.847875] RDX: 0000000020000080 RSI: 00000000c018aec0 RDI: 0000000000000004 [ 50.855149] RBP: 00000000004a28d8 R08: 0000000120080522 R09: 0000000120080522 [ 50.862412] R10: 0000000120080522 R11: 0000000000000217 R12: 00000000004022a0 [ 50.869661] R13: 0000000000402330 R14: 0000000000000000 R15: 0000000000000000 [ 50.877983] Kernel Offset: disabled [ 50.881607] Rebooting in 86400 seconds..