[ 46.932066] audit: type=1800 audit(1585518213.602:29): pid=8005 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 46.982067] audit: type=1800 audit(1585518213.612:30): pid=8005 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 Starting mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.146' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 55.891361] kauditd_printk_skb: 5 callbacks suppressed [ 55.891376] audit: type=1400 audit(1585518222.562:36): avc: denied { map } for pid=8187 comm="syz-executor874" path="/root/syz-executor874640202" dev="sda1" ino=16484 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 executing program [ 56.326622] [ 56.326626] ============================================ [ 56.326628] WARNING: possible recursive locking detected [ 56.326634] 4.19.113-syzkaller #0 Not tainted [ 56.326636] -------------------------------------------- [ 56.326640] syz-executor874/8192 is trying to acquire lock: [ 56.326644] 000000005b226712 ((fb_notifier_list).rwsem){++++}, at: blocking_notifier_call_chain+0x6f/0xa0 [ 56.326663] [ 56.326663] but task is already holding lock: [ 56.326665] 000000005b226712 ((fb_notifier_list).rwsem){++++}, at: blocking_notifier_call_chain+0x6f/0xa0 [ 56.326675] [ 56.326675] other info that might help us debug this: [ 56.326677] Possible unsafe locking scenario: [ 56.326677] [ 56.326679] CPU0 [ 56.326680] ---- [ 56.326681] lock((fb_notifier_list).rwsem); [ 56.326684] lock((fb_notifier_list).rwsem); [ 56.326687] [ 56.326687] *** DEADLOCK *** [ 56.326687] [ 56.326689] May be due to missing lock nesting notation [ 56.326689] [ 56.326693] 3 locks held by syz-executor874/8192: [ 56.326694] #0: 000000002f77d622 (console_lock){+.+.}, at: do_fb_ioctl+0x179/0xab0 [ 56.326706] #1: 000000000f2b070c (&fb_info->lock){+.+.}, at: lock_fb_info+0x1a/0x70 [ 56.326716] #2: 000000005b226712 ((fb_notifier_list).rwsem){++++}, at: blocking_notifier_call_chain+0x6f/0xa0 [ 56.326728] [ 56.326728] stack backtrace: [ 56.326734] CPU: 0 PID: 8192 Comm: syz-executor874 Not tainted 4.19.113-syzkaller #0 [ 56.326738] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 56.326740] Call Trace: [ 56.326755] dump_stack+0x188/0x20d [ 56.326764] __lock_acquire.cold+0x20f/0x4a7 [ 56.326773] ? __schedule+0x86e/0x1d80 [ 56.326779] ? lockdep_hardirqs_on+0x40b/0x5d0 [ 56.326788] ? mark_held_locks+0xf0/0xf0 [ 56.326796] ? ___preempt_schedule+0x16/0x18 [ 56.326803] ? preempt_schedule_common+0x4a/0xc0 [ 56.326809] ? ___preempt_schedule+0x16/0x18 [ 56.326818] ? check_preemption_disabled+0x41/0x280 [ 56.326826] ? delay_tsc+0x8a/0xb0 [ 56.326833] ? vga16fb_update_fix+0x27b/0x4a0 [ 56.326840] lock_acquire+0x170/0x400 [ 56.326848] ? blocking_notifier_call_chain+0x6f/0xa0 [ 56.326855] down_read+0x37/0xb0 [ 56.326862] ? blocking_notifier_call_chain+0x6f/0xa0 [ 56.326869] blocking_notifier_call_chain+0x6f/0xa0 [ 56.326875] fb_set_var+0xc39/0xe00 [ 56.326882] ? fb_set_suspend+0x130/0x130 [ 56.326888] ? _raw_spin_unlock_irqrestore+0xa0/0xe0 [ 56.326897] ? depot_save_stack+0x1d6/0x444 [ 56.326905] ? save_stack+0x89/0xa0 [ 56.326911] ? __kasan_slab_free+0xf7/0x140 [ 56.326916] ? kfree+0xce/0x220 [ 56.326923] ? bit_cursor+0x916/0x1900 [ 56.326929] ? fbcon_cursor+0x572/0x760 [ 56.326935] ? fbcon_blank+0x926/0xf00 [ 56.326942] ? do_unblank_screen+0x241/0x620 [ 56.326948] ? fbcon_event_notify+0x1a11/0x1d54 [ 56.326954] ? notifier_call_chain+0xc0/0x230 [ 56.326960] ? vga16fb_imageblit+0xc49/0x2210 [ 56.326971] ? bit_cursor+0xa62/0x1900 [ 56.326978] ? fb_videomode_to_var+0xf/0x610 [ 56.326985] fbcon_switch+0x520/0x1970 [ 56.326992] ? fbcon_set_def_font+0x370/0x370 [ 56.327001] ? fbcon_cursor+0x572/0x760 [ 56.327007] ? bit_clear+0x4e0/0x4e0 [ 56.327014] ? fbcon_set_origin+0x26/0x50 [ 56.327021] redraw_screen+0x37d/0x870 [ 56.327027] ? con_flush_chars+0x90/0x90 [ 56.327034] ? fbcon_cursor+0x572/0x760 [ 56.327040] ? bit_clear+0x4e0/0x4e0 [ 56.327047] fbcon_blank+0x9ab/0xf00 [ 56.327054] ? fbcon_cursor+0x760/0x760 [ 56.327060] ? mark_held_locks+0xf0/0xf0 [ 56.327068] ? mark_held_locks+0xf0/0xf0 [ 56.327075] ? __lock_is_held+0xad/0x140 [ 56.327083] do_unblank_screen+0x241/0x620 [ 56.327090] fbcon_event_notify+0x1a11/0x1d54 [ 56.327097] ? lock_acquire+0x170/0x400 [ 56.327104] notifier_call_chain+0xc0/0x230 [ 56.327112] blocking_notifier_call_chain+0x85/0xa0 [ 56.327118] fb_blank+0x195/0x1d0 [ 56.327124] ? fb_seq_stop+0x20/0x20 [ 56.327129] ? lock_acquire+0x170/0x400 [ 56.327134] ? do_fb_ioctl+0x179/0xab0 [ 56.327141] do_fb_ioctl+0x1d9/0xab0 [ 56.327147] ? lock_downgrade+0x740/0x740 [ 56.327153] ? fb_read+0x570/0x570 [ 56.327161] ? avc_has_extended_perms+0x9c6/0x1030 [ 56.327168] ? avc_ss_reset+0x180/0x180 [ 56.327174] ? mark_held_locks+0xf0/0xf0 [ 56.327181] ? lock_downgrade+0x740/0x740 [ 56.327188] ? _raw_spin_unlock_irqrestore+0x67/0xe0 [ 56.327194] ? __lock_acquire+0x6ee/0x49c0 [ 56.327203] ? find_held_lock+0x2d/0x110 [ 56.327215] ? debug_object_active_state+0x25d/0x380 [ 56.327230] fb_ioctl+0xdd/0x130 [ 56.327240] ? do_fb_ioctl+0xab0/0xab0 [ 56.327252] do_vfs_ioctl+0xcda/0x12e0 [ 56.327265] ? selinux_file_ioctl+0x46c/0x5d0 [ 56.327276] ? selinux_file_ioctl+0x125/0x5d0 [ 56.327282] ? ioctl_preallocate+0x200/0x200 [ 56.327289] ? selinux_file_mprotect+0x600/0x600 [ 56.327299] ? blkcg_maybe_throttle_current+0x591/0xc30 [ 56.327304] ? lock_downgrade+0x740/0x740 [ 56.327313] ? security_file_ioctl+0x6c/0xb0 [ 56.327319] ksys_ioctl+0x9b/0xc0 [ 56.327326] __x64_sys_ioctl+0x6f/0xb0 [ 56.327332] ? lockdep_hardirqs_on+0x40b/0x5d0 [ 56.327339] do_syscall_64+0xf9/0x620 [ 56.327346] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 56.327352] RIP: 0033:0x446179 executing program [ 56.327360] Code: 8d cd fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 5b cd fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 56.327363] RSP: 002b:00007ffdb039cfd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 56.327370] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446179 [ 56.327373] RDX: 0000000000000000 RSI: 0000000000004611 RDI: 0000000000000004 [ 56.327377] RBP: 000000000000da3d R08: 000000000000da3d R09: 00000000004033f0 [ 56.327381] R10: 00007ffdb039ceb0 R11: 0000000000000246 R12: 0000000000403360 [ 56.327384] R13: 00000000004033f0 R14: 0000000000000000 R15: 0000000000000000 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program