[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty1. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.197' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 72.357445][ T8459] ================================================================== [ 72.365671][ T8459] BUG: KASAN: null-ptr-deref in bdi_put+0x22/0xa0 [ 72.372103][ T8459] Write of size 4 at addr 0000000000000040 by task syz-executor719/8459 [ 72.380539][ T8459] [ 72.382869][ T8459] CPU: 1 PID: 8459 Comm: syz-executor719 Not tainted 5.10.0-rc6-next-20201207-syzkaller #0 [ 72.392848][ T8459] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 72.402951][ T8459] Call Trace: [ 72.406292][ T8459] dump_stack+0x107/0x163 [ 72.410719][ T8459] ? bdi_put+0x22/0xa0 [ 72.414796][ T8459] ? bdi_put+0x22/0xa0 [ 72.418886][ T8459] kasan_report.cold+0x5f/0xd5 [ 72.424200][ T8459] ? bdi_put+0x22/0xa0 [ 72.428289][ T8459] check_memory_region+0x13d/0x180 [ 72.433528][ T8459] bdi_put+0x22/0xa0 [ 72.437444][ T8459] bdev_evict_inode+0x280/0x4a0 [ 72.442308][ T8459] ? __blkdev_direct_IO_simple+0x8c0/0x8c0 [ 72.448147][ T8459] evict+0x2ed/0x6b0 [ 72.452063][ T8459] iput.part.0+0x41e/0x840 [ 72.456526][ T8459] ? __remove_inode_hash+0x130/0x130 [ 72.461830][ T8459] iput+0x58/0x70 [ 72.465484][ T8459] dentry_unlink_inode+0x2b1/0x3d0 [ 72.470620][ T8459] __dentry_kill+0x3c0/0x640 [ 72.475231][ T8459] ? dput+0x35/0xc10 [ 72.479145][ T8459] ? dput+0x35/0xc10 [ 72.483055][ T8459] dput+0x786/0xc10 [ 72.486902][ T8459] shrink_dcache_for_umount+0x11f/0x330 [ 72.492578][ T8459] generic_shutdown_super+0x68/0x370 [ 72.497890][ T8459] kill_anon_super+0x36/0x60 [ 72.502501][ T8459] deactivate_locked_super+0x94/0x160 [ 72.507917][ T8459] deactivate_super+0xad/0xd0 [ 72.512609][ T8459] cleanup_mnt+0x3a3/0x530 [ 72.517051][ T8459] task_work_run+0xdd/0x190 [ 72.521593][ T8459] exit_to_user_mode_prepare+0x1f0/0x200 [ 72.527252][ T8459] syscall_exit_to_user_mode+0x19/0x50 [ 72.532744][ T8459] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 72.538657][ T8459] RIP: 0033:0x444439 [ 72.542652][ T8459] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 db d7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 72.562383][ T8459] RSP: 002b:00007ffc4e2a8a38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 72.570827][ T8459] RAX: ffffffffffffffea RBX: 00007ffc4e2a8a40 RCX: 0000000000444439 [ 72.578819][ T8459] RDX: 0000000020000100 RSI: 00000000200000c0 RDI: 0000000000000000 [ 72.586905][ T8459] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000400c60 [ 72.595019][ T8459] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004020a0 [ 72.604165][ T8459] R13: 0000000000402130 R14: 0000000000000000 R15: 0000000000000000 [ 72.612185][ T8459] ================================================================== [ 72.620271][ T8459] Disabling lock debugging due to kernel taint [ 72.626970][ T8459] Kernel panic - not syncing: panic_on_warn set ... [ 72.633598][ T8459] CPU: 0 PID: 8459 Comm: syz-executor719 Tainted: G B 5.10.0-rc6-next-20201207-syzkaller #0 [ 72.644973][ T8459] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 72.655019][ T8459] Call Trace: [ 72.658312][ T8459] dump_stack+0x107/0x163 [ 72.662642][ T8459] panic+0x343/0x77f [ 72.666529][ T8459] ? __warn_printk+0xf3/0xf3 [ 72.671112][ T8459] ? preempt_schedule_common+0x59/0xc0 [ 72.676762][ T8459] ? bdi_put+0x22/0xa0 [ 72.680861][ T8459] ? preempt_schedule_thunk+0x16/0x18 [ 72.686525][ T8459] ? trace_hardirqs_on+0x38/0x1c0 [ 72.691546][ T8459] ? trace_hardirqs_on+0x51/0x1c0 [ 72.696643][ T8459] ? bdi_put+0x22/0xa0 [ 72.700814][ T8459] ? bdi_put+0x22/0xa0 [ 72.704882][ T8459] end_report+0x58/0x5e [ 72.709053][ T8459] kasan_report.cold+0x67/0xd5 [ 72.713822][ T8459] ? bdi_put+0x22/0xa0 [ 72.717970][ T8459] check_memory_region+0x13d/0x180 [ 72.723062][ T8459] bdi_put+0x22/0xa0 [ 72.726941][ T8459] bdev_evict_inode+0x280/0x4a0 [ 72.731787][ T8459] ? __blkdev_direct_IO_simple+0x8c0/0x8c0 [ 72.737602][ T8459] evict+0x2ed/0x6b0 [ 72.741487][ T8459] iput.part.0+0x41e/0x840 [ 72.745897][ T8459] ? __remove_inode_hash+0x130/0x130 [ 72.751783][ T8459] iput+0x58/0x70 [ 72.755410][ T8459] dentry_unlink_inode+0x2b1/0x3d0 [ 72.760506][ T8459] __dentry_kill+0x3c0/0x640 [ 72.765102][ T8459] ? dput+0x35/0xc10 [ 72.769015][ T8459] ? dput+0x35/0xc10 [ 72.772919][ T8459] dput+0x786/0xc10 [ 72.776742][ T8459] shrink_dcache_for_umount+0x11f/0x330 [ 72.782625][ T8459] generic_shutdown_super+0x68/0x370 [ 72.787922][ T8459] kill_anon_super+0x36/0x60 [ 72.792520][ T8459] deactivate_locked_super+0x94/0x160 [ 72.797879][ T8459] deactivate_super+0xad/0xd0 [ 72.802636][ T8459] cleanup_mnt+0x3a3/0x530 [ 72.807035][ T8459] task_work_run+0xdd/0x190 [ 72.811539][ T8459] exit_to_user_mode_prepare+0x1f0/0x200 [ 72.819392][ T8459] syscall_exit_to_user_mode+0x19/0x50 [ 72.824848][ T8459] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 72.830736][ T8459] RIP: 0033:0x444439 [ 72.834626][ T8459] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 db d7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 72.854233][ T8459] RSP: 002b:00007ffc4e2a8a38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 72.862643][ T8459] RAX: ffffffffffffffea RBX: 00007ffc4e2a8a40 RCX: 0000000000444439 [ 72.870623][ T8459] RDX: 0000000020000100 RSI: 00000000200000c0 RDI: 0000000000000000 [ 72.878674][ T8459] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000400c60 [ 72.886765][ T8459] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004020a0 [ 72.894870][ T8459] R13: 0000000000402130 R14: 0000000000000000 R15: 0000000000000000 [ 72.903783][ T8459] Kernel Offset: disabled [ 72.908122][ T8459] Rebooting in 86400 seconds..