[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [ 34.650219] restorecond (6134) used greatest stack depth: 15232 bytes left [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.917409] audit: type=1800 audit(1542119664.139:33): pid=6044 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 [ 34.946463] audit: type=1800 audit(1542119664.139:34): pid=6044 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: [ 50.732235] audit: type=1400 audit(1542119679.949:35): avc: denied { map } for pid=6222 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 '10.128.0.23' (ECDSA) to the list of known hosts. executing program [ 57.305636] audit: type=1400 audit(1542119686.519:36): avc: denied { map } for pid=6234 comm="syz-executor942" path="/root/syz-executor942201269" 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 [ 57.313068] ================================================================== [ 57.339319] BUG: KASAN: null-ptr-deref in refcount_sub_and_test_checked+0x9d/0x310 [ 57.347027] Read of size 4 at addr 0000000000000020 by task syz-executor942/6234 [ 57.354538] [ 57.356156] CPU: 1 PID: 6234 Comm: syz-executor942 Not tainted 4.20.0-rc2+ #112 [ 57.363591] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.372922] Call Trace: [ 57.375492] dump_stack+0x244/0x39d [ 57.379109] ? dump_stack_print_info.cold.1+0x20/0x20 [ 57.384298] ? do_group_exit+0x177/0x440 [ 57.388343] ? __x64_sys_exit_group+0x3e/0x50 [ 57.392843] ? vprintk_func+0x85/0x181 [ 57.396726] kasan_report.cold.8+0x6d/0x309 [ 57.401045] ? refcount_sub_and_test_checked+0x9d/0x310 [ 57.406451] check_memory_region+0x13e/0x1b0 [ 57.410849] kasan_check_read+0x11/0x20 [ 57.414806] refcount_sub_and_test_checked+0x9d/0x310 [ 57.419982] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 57.424548] ? refcount_inc_not_zero_checked+0x2f0/0x2f0 [ 57.429984] ? vb2_vmalloc_put+0x5f/0x80 [ 57.434031] ? trace_hardirqs_off_caller+0x310/0x310 [ 57.439118] ? __kasan_slab_free+0x119/0x150 [ 57.443528] refcount_dec_and_test_checked+0x1a/0x20 [ 57.448612] vb2_vmalloc_put+0x19/0x80 [ 57.452512] __vb2_buf_mem_free+0x112/0x210 [ 57.456829] ? vb2_vmalloc_get_dmabuf+0x300/0x300 [ 57.461657] __vb2_queue_free+0x830/0xa30 [ 57.465791] ? trace_hardirqs_off_caller+0x310/0x310 [ 57.470879] ? __vb2_plane_dmabuf_put.isra.5+0x310/0x310 [ 57.476315] vb2_core_queue_release+0x62/0x80 [ 57.480793] _vb2_fop_release+0x1d2/0x2b0 [ 57.484926] vb2_fop_release+0x77/0xc0 [ 57.488800] vivid_fop_release+0x18e/0x440 [ 57.493022] ? vivid_remove+0x460/0x460 [ 57.497282] v4l2_release+0x224/0x3a0 [ 57.501068] ? dev_debug_store+0x140/0x140 [ 57.505283] __fput+0x385/0xa30 [ 57.508548] ? get_max_files+0x20/0x20 [ 57.512421] ? trace_hardirqs_on+0xbd/0x310 [ 57.516734] ? kasan_check_read+0x11/0x20 [ 57.520880] ? task_work_run+0x1af/0x2a0 [ 57.524925] ? trace_hardirqs_off_caller+0x310/0x310 [ 57.530020] ____fput+0x15/0x20 [ 57.533285] task_work_run+0x1e8/0x2a0 [ 57.537160] ? task_work_cancel+0x240/0x240 [ 57.541478] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 57.547022] ? switch_task_namespaces+0x9d/0xd0 [ 57.551684] do_exit+0x1ad6/0x26d0 [ 57.555216] ? mm_update_next_owner+0x990/0x990 [ 57.559875] ? kvfree+0x66/0x70 [ 57.563174] ? video_usercopy+0x79b/0x1760 [ 57.567393] ? v4l_s_fmt+0x990/0x990 [ 57.571115] ? v4l_enumstd+0x70/0x70 [ 57.574807] ? rcu_softirq_qs+0x20/0x20 [ 57.578773] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 57.584292] ? avc_has_extended_perms+0xab2/0x15a0 [ 57.589227] ? avc_ss_reset+0x190/0x190 [ 57.593226] ? save_stack+0x43/0xd0 [ 57.596848] ? __kasan_slab_free+0x102/0x150 [ 57.601248] ? kasan_slab_free+0xe/0x10 [ 57.605218] ? kmem_cache_free+0x83/0x290 [ 57.609349] ? do_sys_open+0x54d/0x700 [ 57.613215] ? __x64_sys_open+0x7e/0xc0 [ 57.617177] ? do_syscall_64+0x1b9/0x820 [ 57.621224] ? kasan_check_read+0x11/0x20 [ 57.625367] ? perf_trace_sched_process_exec+0x860/0x860 [ 57.630805] ? video_usercopy+0x1760/0x1760 [ 57.635106] ? video_ioctl2+0x2c/0x33 [ 57.638893] ? v4l2_ioctl+0x15c/0x1b0 [ 57.642693] ? video_devdata+0xa0/0xa0 [ 57.646561] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 57.652081] ? do_vfs_ioctl+0x201/0x1790 [ 57.656126] ? ioctl_preallocate+0x300/0x300 [ 57.660518] ? selinux_file_mprotect+0x620/0x620 [ 57.665260] ? rcu_read_lock_sched_held+0x14f/0x180 [ 57.670278] ? kmem_cache_free+0x1cb/0x290 [ 57.674497] ? putname+0xf7/0x130 [ 57.677937] do_group_exit+0x177/0x440 [ 57.681856] ? trace_hardirqs_on+0xbd/0x310 [ 57.686161] ? __ia32_sys_exit+0x50/0x50 [ 57.690208] ? trace_hardirqs_off_caller+0x310/0x310 [ 57.695293] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 57.700812] ? ksys_ioctl+0x81/0xd0 [ 57.704433] __x64_sys_exit_group+0x3e/0x50 [ 57.708739] do_syscall_64+0x1b9/0x820 [ 57.712608] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 57.717959] ? syscall_return_slowpath+0x5e0/0x5e0 [ 57.722870] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 57.727700] ? trace_hardirqs_on_caller+0x310/0x310 [ 57.732699] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 57.737698] ? prepare_exit_to_usermode+0x291/0x3b0 [ 57.742713] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 57.747542] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 57.752712] RIP: 0033:0x442c78 [ 57.755896] Code: Bad RIP value. [ 57.759243] RSP: 002b:00007ffe827a7d38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 57.766929] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442c78 [ 57.774183] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 57.781435] RBP: 00000000004c2848 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 57.788703] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 57.795952] R13: 00000000006d4180 R14: 0000000000000000 R15: 0000000000000000 [ 57.803210] ================================================================== [ 57.810560] Disabling lock debugging due to kernel taint [ 57.817930] Kernel panic - not syncing: panic_on_warn set ... [ 57.823815] CPU: 0 PID: 6234 Comm: syz-executor942 Tainted: G B 4.20.0-rc2+ #112 [ 57.832628] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.841959] Call Trace: [ 57.844570] dump_stack+0x244/0x39d [ 57.848181] ? dump_stack_print_info.cold.1+0x20/0x20 [ 57.853354] panic+0x2ad/0x55c [ 57.856525] ? add_taint.cold.5+0x16/0x16 [ 57.860655] ? preempt_schedule+0x4d/0x60 [ 57.864786] ? ___preempt_schedule+0x16/0x18 [ 57.869177] ? trace_hardirqs_on+0xb4/0x310 [ 57.873491] kasan_end_report+0x47/0x4f [ 57.877446] kasan_report.cold.8+0x76/0x309 [ 57.881747] ? refcount_sub_and_test_checked+0x9d/0x310 [ 57.887089] check_memory_region+0x13e/0x1b0 [ 57.891479] kasan_check_read+0x11/0x20 [ 57.895451] refcount_sub_and_test_checked+0x9d/0x310 [ 57.900624] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 57.905189] ? refcount_inc_not_zero_checked+0x2f0/0x2f0 [ 57.910633] ? vb2_vmalloc_put+0x5f/0x80 [ 57.914693] ? trace_hardirqs_off_caller+0x310/0x310 [ 57.919779] ? __kasan_slab_free+0x119/0x150 [ 57.924168] refcount_dec_and_test_checked+0x1a/0x20 [ 57.929257] vb2_vmalloc_put+0x19/0x80 [ 57.933127] __vb2_buf_mem_free+0x112/0x210 [ 57.937442] ? vb2_vmalloc_get_dmabuf+0x300/0x300 [ 57.942279] __vb2_queue_free+0x830/0xa30 [ 57.946414] ? trace_hardirqs_off_caller+0x310/0x310 [ 57.951515] ? __vb2_plane_dmabuf_put.isra.5+0x310/0x310 [ 57.956951] vb2_core_queue_release+0x62/0x80 [ 57.961429] _vb2_fop_release+0x1d2/0x2b0 [ 57.965586] vb2_fop_release+0x77/0xc0 [ 57.969453] vivid_fop_release+0x18e/0x440 [ 57.973675] ? vivid_remove+0x460/0x460 [ 57.977629] v4l2_release+0x224/0x3a0 [ 57.981416] ? dev_debug_store+0x140/0x140 [ 57.985648] __fput+0x385/0xa30 [ 57.988918] ? get_max_files+0x20/0x20 [ 57.992784] ? trace_hardirqs_on+0xbd/0x310 [ 57.997087] ? kasan_check_read+0x11/0x20 [ 58.001216] ? task_work_run+0x1af/0x2a0 [ 58.005281] ? trace_hardirqs_off_caller+0x310/0x310 [ 58.010367] ____fput+0x15/0x20 [ 58.013624] task_work_run+0x1e8/0x2a0 [ 58.017492] ? task_work_cancel+0x240/0x240 [ 58.021798] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 58.027321] ? switch_task_namespaces+0x9d/0xd0 [ 58.031975] do_exit+0x1ad6/0x26d0 [ 58.035498] ? mm_update_next_owner+0x990/0x990 [ 58.040167] ? kvfree+0x66/0x70 [ 58.043429] ? video_usercopy+0x79b/0x1760 [ 58.047646] ? v4l_s_fmt+0x990/0x990 [ 58.051346] ? v4l_enumstd+0x70/0x70 [ 58.055037] ? rcu_softirq_qs+0x20/0x20 [ 58.058994] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 58.064511] ? avc_has_extended_perms+0xab2/0x15a0 [ 58.069430] ? avc_ss_reset+0x190/0x190 [ 58.073391] ? save_stack+0x43/0xd0 [ 58.077004] ? __kasan_slab_free+0x102/0x150 [ 58.081391] ? kasan_slab_free+0xe/0x10 [ 58.085349] ? kmem_cache_free+0x83/0x290 [ 58.089493] ? do_sys_open+0x54d/0x700 [ 58.093359] ? __x64_sys_open+0x7e/0xc0 [ 58.097310] ? do_syscall_64+0x1b9/0x820 [ 58.101384] ? kasan_check_read+0x11/0x20 [ 58.105517] ? perf_trace_sched_process_exec+0x860/0x860 [ 58.110948] ? video_usercopy+0x1760/0x1760 [ 58.115247] ? video_ioctl2+0x2c/0x33 [ 58.119029] ? v4l2_ioctl+0x15c/0x1b0 [ 58.122806] ? video_devdata+0xa0/0xa0 [ 58.126680] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 58.132201] ? do_vfs_ioctl+0x201/0x1790 [ 58.136243] ? ioctl_preallocate+0x300/0x300 [ 58.140646] ? selinux_file_mprotect+0x620/0x620 [ 58.145401] ? rcu_read_lock_sched_held+0x14f/0x180 [ 58.150455] ? kmem_cache_free+0x1cb/0x290 [ 58.154721] ? putname+0xf7/0x130 [ 58.158175] do_group_exit+0x177/0x440 [ 58.162047] ? trace_hardirqs_on+0xbd/0x310 [ 58.166364] ? __ia32_sys_exit+0x50/0x50 [ 58.170416] ? trace_hardirqs_off_caller+0x310/0x310 [ 58.175501] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 58.181017] ? ksys_ioctl+0x81/0xd0 [ 58.184625] __x64_sys_exit_group+0x3e/0x50 [ 58.188926] do_syscall_64+0x1b9/0x820 [ 58.192791] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 58.198152] ? syscall_return_slowpath+0x5e0/0x5e0 [ 58.203061] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 58.207883] ? trace_hardirqs_on_caller+0x310/0x310 [ 58.212893] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 58.217891] ? prepare_exit_to_usermode+0x291/0x3b0 [ 58.222887] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 58.227713] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 58.232880] RIP: 0033:0x442c78 [ 58.236054] Code: 00 00 ea dc 40 00 00 00 00 00 ea dc 40 00 00 00 00 00 ea dc 40 00 00 00 00 00 ea dc 40 00 00 00 00 00 c8 de 40 00 00 00 00 00 dc 40 00 00 00 00 00 ea dc 40 00 00 00 00 00 ea dc 40 00 00 00 [ 58.254937] RSP: 002b:00007ffe827a7d38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 58.262623] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442c78 [ 58.269870] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 58.277119] RBP: 00000000004c2848 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 58.284370] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 58.291619] R13: 00000000006d4180 R14: 0000000000000000 R15: 0000000000000000 [ 58.299737] Kernel Offset: disabled [ 58.303358] Rebooting in 86400 seconds..