[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 29.315747] kauditd_printk_skb: 9 callbacks suppressed [ 29.315757] audit: type=1800 audit(1541334242.938:33): pid=5577 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 29.344324] audit: type=1800 audit(1541334242.948:34): pid=5577 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 32.619187] audit: type=1400 audit(1541334246.248:35): avc: denied { map } for pid=5752 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 Warning: Permanently added '10.128.0.115' (ECDSA) to the list of known hosts. executing program [ 39.280029] audit: type=1400 audit(1541334252.908:36): avc: denied { map } for pid=5766 comm="syz-executor763" path="/root/syz-executor763880000" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 39.292385] ================================================================== [ 39.313787] BUG: KASAN: null-ptr-deref in refcount_sub_and_test_checked+0x9d/0x310 [ 39.321510] Read of size 4 at addr 0000000000000020 by task syz-executor763/5766 [ 39.329032] [ 39.330654] CPU: 1 PID: 5766 Comm: syz-executor763 Not tainted 4.19.0+ #98 [ 39.337653] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 39.346998] Call Trace: [ 39.349589] dump_stack+0x244/0x39d [ 39.353211] ? dump_stack_print_info.cold.1+0x20/0x20 [ 39.358442] ? do_group_exit+0x177/0x440 [ 39.362506] ? __x64_sys_exit_group+0x3e/0x50 [ 39.367003] ? vprintk_func+0x85/0x181 [ 39.370891] kasan_report.cold.8+0x6d/0x309 [ 39.375205] ? refcount_sub_and_test_checked+0x9d/0x310 [ 39.380568] check_memory_region+0x13e/0x1b0 [ 39.385059] kasan_check_read+0x11/0x20 [ 39.389027] refcount_sub_and_test_checked+0x9d/0x310 [ 39.394330] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 39.399053] ? refcount_inc_not_zero_checked+0x2f0/0x2f0 [ 39.404501] ? vb2_vmalloc_put+0x5f/0x80 [ 39.408557] ? trace_hardirqs_off_caller+0x310/0x310 [ 39.413696] ? __kasan_slab_free+0x119/0x150 [ 39.418127] refcount_dec_and_test_checked+0x1a/0x20 [ 39.423236] vb2_vmalloc_put+0x19/0x80 [ 39.427123] __vb2_buf_mem_free+0x112/0x210 [ 39.431437] ? vb2_vmalloc_get_dmabuf+0x300/0x300 [ 39.436275] __vb2_queue_free+0x830/0xa30 [ 39.440420] ? v4l2_m2m_job_finish+0x4c0/0x4c0 [ 39.445516] ? __vb2_plane_dmabuf_put.isra.5+0x310/0x310 [ 39.450965] ? vidioc_querycap+0xd0/0xd0 [ 39.455019] vb2_core_queue_release+0x62/0x80 [ 39.459511] vb2_queue_release+0x15/0x20 [ 39.463572] v4l2_m2m_ctx_release+0x2a/0x35 [ 39.468059] vim2m_release+0xe6/0x150 [ 39.471865] v4l2_release+0x224/0x3a0 [ 39.475658] ? dev_debug_store+0x140/0x140 [ 39.479891] __fput+0x385/0xa30 [ 39.483165] ? get_max_files+0x20/0x20 [ 39.487048] ? trace_hardirqs_on+0xbd/0x310 [ 39.491364] ? kasan_check_read+0x11/0x20 [ 39.495505] ? task_work_run+0x1af/0x2a0 [ 39.499562] ? trace_hardirqs_off_caller+0x310/0x310 [ 39.504663] ____fput+0x15/0x20 [ 39.507938] task_work_run+0x1e8/0x2a0 [ 39.511819] ? task_work_cancel+0x240/0x240 [ 39.516135] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 39.521666] ? switch_task_namespaces+0x9d/0xd0 [ 39.526331] do_exit+0x1ad6/0x26d0 [ 39.529870] ? mm_update_next_owner+0x990/0x990 [ 39.534535] ? kvfree+0x66/0x70 [ 39.537811] ? video_usercopy+0x79b/0x1760 [ 39.542039] ? v4l_s_fmt+0x990/0x990 [ 39.545752] ? v4l_enumstd+0x70/0x70 [ 39.549462] ? rcu_softirq_qs+0x20/0x20 [ 39.553440] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 39.558994] ? avc_has_extended_perms+0xab2/0x15a0 [ 39.563926] ? avc_ss_reset+0x190/0x190 [ 39.567915] ? save_stack+0x43/0xd0 [ 39.571549] ? __kasan_slab_free+0x102/0x150 [ 39.575951] ? kasan_slab_free+0xe/0x10 [ 39.579923] ? kmem_cache_free+0x83/0x290 [ 39.584070] ? kasan_check_read+0x11/0x20 [ 39.588217] ? perf_trace_sched_process_exec+0x860/0x860 [ 39.593667] ? video_usercopy+0x1760/0x1760 [ 39.598039] ? video_ioctl2+0x2c/0x33 [ 39.601840] ? v4l2_ioctl+0x15c/0x1b0 [ 39.605740] ? video_devdata+0xa0/0xa0 [ 39.609627] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 39.615158] ? do_vfs_ioctl+0x201/0x1790 [ 39.619216] ? ioctl_preallocate+0x300/0x300 [ 39.623626] ? selinux_file_mprotect+0x620/0x620 [ 39.628391] ? rcu_read_lock_sched_held+0x14f/0x180 [ 39.633443] ? kmem_cache_free+0x1db/0x290 [ 39.637715] ? putname+0xf7/0x130 [ 39.641169] do_group_exit+0x177/0x440 [ 39.645058] ? trace_hardirqs_on+0xbd/0x310 [ 39.649464] ? __ia32_sys_exit+0x50/0x50 [ 39.653523] ? trace_hardirqs_off_caller+0x310/0x310 [ 39.658732] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 39.664267] ? ksys_ioctl+0x81/0xd0 [ 39.667894] __x64_sys_exit_group+0x3e/0x50 [ 39.672211] do_syscall_64+0x1b9/0x820 [ 39.676093] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 39.681456] ? syscall_return_slowpath+0x5e0/0x5e0 [ 39.686380] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 39.691220] ? trace_hardirqs_on_caller+0x310/0x310 [ 39.696243] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 39.701253] ? prepare_exit_to_usermode+0x291/0x3b0 [ 39.706270] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 39.711272] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 39.716504] RIP: 0033:0x442cc8 [ 39.719717] Code: Bad RIP value. [ 39.723089] RSP: 002b:00007ffc275f1cb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 39.731010] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442cc8 [ 39.738273] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 39.745535] RBP: 00000000004c2888 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 39.752800] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 39.760152] R13: 00000000006d4180 R14: 0000000000000000 R15: 0000000000000000 [ 39.767423] ================================================================== [ 39.774821] Disabling lock debugging due to kernel taint [ 39.781023] Kernel panic - not syncing: panic_on_warn set ... [ 39.786926] CPU: 1 PID: 5766 Comm: syz-executor763 Tainted: G B 4.19.0+ #98 [ 39.795325] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 39.804670] Call Trace: [ 39.807363] dump_stack+0x244/0x39d [ 39.811000] ? dump_stack_print_info.cold.1+0x20/0x20 [ 39.816189] panic+0x2ad/0x55c [ 39.819374] ? add_taint.cold.5+0x16/0x16 [ 39.823512] ? preempt_schedule+0x4d/0x60 [ 39.827649] ? ___preempt_schedule+0x16/0x18 [ 39.832049] ? trace_hardirqs_on+0xb4/0x310 [ 39.836361] kasan_end_report+0x47/0x4f [ 39.840453] kasan_report.cold.8+0x76/0x309 [ 39.844768] ? refcount_sub_and_test_checked+0x9d/0x310 [ 39.850132] check_memory_region+0x13e/0x1b0 [ 39.854542] kasan_check_read+0x11/0x20 [ 39.858507] refcount_sub_and_test_checked+0x9d/0x310 [ 39.863707] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 39.868323] ? refcount_inc_not_zero_checked+0x2f0/0x2f0 [ 39.873771] ? vb2_vmalloc_put+0x5f/0x80 [ 39.877825] ? trace_hardirqs_off_caller+0x310/0x310 [ 39.882922] ? __kasan_slab_free+0x119/0x150 [ 39.887337] refcount_dec_and_test_checked+0x1a/0x20 [ 39.892434] vb2_vmalloc_put+0x19/0x80 [ 39.896316] __vb2_buf_mem_free+0x112/0x210 [ 39.900718] ? vb2_vmalloc_get_dmabuf+0x300/0x300 [ 39.905601] __vb2_queue_free+0x830/0xa30 [ 39.909747] ? v4l2_m2m_job_finish+0x4c0/0x4c0 [ 39.914352] ? __vb2_plane_dmabuf_put.isra.5+0x310/0x310 [ 39.919795] ? vidioc_querycap+0xd0/0xd0 [ 39.923935] vb2_core_queue_release+0x62/0x80 [ 39.928421] vb2_queue_release+0x15/0x20 [ 39.932474] v4l2_m2m_ctx_release+0x2a/0x35 [ 39.936783] vim2m_release+0xe6/0x150 [ 39.940575] v4l2_release+0x224/0x3a0 [ 39.944367] ? dev_debug_store+0x140/0x140 [ 39.948654] __fput+0x385/0xa30 [ 39.951950] ? get_max_files+0x20/0x20 [ 39.955834] ? trace_hardirqs_on+0xbd/0x310 [ 39.960147] ? kasan_check_read+0x11/0x20 [ 39.964288] ? task_work_run+0x1af/0x2a0 [ 39.968341] ? trace_hardirqs_off_caller+0x310/0x310 [ 39.973442] ____fput+0x15/0x20 [ 39.976731] task_work_run+0x1e8/0x2a0 [ 39.980611] ? task_work_cancel+0x240/0x240 [ 39.984927] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 39.990504] ? switch_task_namespaces+0x9d/0xd0 [ 39.995168] do_exit+0x1ad6/0x26d0 [ 39.998712] ? mm_update_next_owner+0x990/0x990 [ 40.003371] ? kvfree+0x66/0x70 [ 40.006642] ? video_usercopy+0x79b/0x1760 [ 40.010882] ? v4l_s_fmt+0x990/0x990 [ 40.014586] ? v4l_enumstd+0x70/0x70 [ 40.018299] ? rcu_softirq_qs+0x20/0x20 [ 40.022283] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.027821] ? avc_has_extended_perms+0xab2/0x15a0 [ 40.032748] ? avc_ss_reset+0x190/0x190 [ 40.036726] ? save_stack+0x43/0xd0 [ 40.040345] ? __kasan_slab_free+0x102/0x150 [ 40.044798] ? kasan_slab_free+0xe/0x10 [ 40.048810] ? kmem_cache_free+0x83/0x290 [ 40.053013] ? kasan_check_read+0x11/0x20 [ 40.057159] ? perf_trace_sched_process_exec+0x860/0x860 [ 40.062608] ? video_usercopy+0x1760/0x1760 [ 40.066921] ? video_ioctl2+0x2c/0x33 [ 40.070734] ? v4l2_ioctl+0x15c/0x1b0 [ 40.074523] ? video_devdata+0xa0/0xa0 [ 40.078403] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.083935] ? do_vfs_ioctl+0x201/0x1790 [ 40.087986] ? ioctl_preallocate+0x300/0x300 [ 40.092388] ? selinux_file_mprotect+0x620/0x620 [ 40.097140] ? rcu_read_lock_sched_held+0x14f/0x180 [ 40.102148] ? kmem_cache_free+0x1db/0x290 [ 40.106372] ? putname+0xf7/0x130 [ 40.109818] do_group_exit+0x177/0x440 [ 40.113717] ? trace_hardirqs_on+0xbd/0x310 [ 40.118031] ? __ia32_sys_exit+0x50/0x50 [ 40.122089] ? trace_hardirqs_off_caller+0x310/0x310 [ 40.127184] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.132756] ? ksys_ioctl+0x81/0xd0 [ 40.136382] __x64_sys_exit_group+0x3e/0x50 [ 40.140720] do_syscall_64+0x1b9/0x820 [ 40.144599] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 40.150042] ? syscall_return_slowpath+0x5e0/0x5e0 [ 40.154961] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.159798] ? trace_hardirqs_on_caller+0x310/0x310 [ 40.164806] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 40.169813] ? prepare_exit_to_usermode+0x291/0x3b0 [ 40.174819] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.179678] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.184858] RIP: 0033:0x442cc8 [ 40.188053] Code: Bad RIP value. [ 40.191418] RSP: 002b:00007ffc275f1cb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 40.199116] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442cc8 [ 40.206375] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 40.213634] RBP: 00000000004c2888 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 40.220914] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 40.228174] R13: 00000000006d4180 R14: 0000000000000000 R15: 0000000000000000 [ 40.237054] Kernel Offset: disabled [ 40.240696] Rebooting in 86400 seconds..