[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty1. [ 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 '10.128.0.91' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 68.166901][ T8484] ================================================================== [ 68.175114][ T8484] BUG: KASAN: null-ptr-deref in bdi_put+0x22/0xa0 [ 68.181526][ T8484] Write of size 4 at addr 0000000000000040 by task syz-executor868/8484 [ 68.189835][ T8484] [ 68.192143][ T8484] CPU: 0 PID: 8484 Comm: syz-executor868 Not tainted 5.10.0-next-20201223-syzkaller #0 [ 68.201775][ T8484] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 68.211817][ T8484] Call Trace: [ 68.215083][ T8484] dump_stack+0x107/0x163 [ 68.219403][ T8484] ? bdi_put+0x22/0xa0 [ 68.223469][ T8484] ? bdi_put+0x22/0xa0 [ 68.227539][ T8484] kasan_report.cold+0x5f/0xd5 [ 68.232305][ T8484] ? bdi_put+0x22/0xa0 [ 68.236402][ T8484] check_memory_region+0x13d/0x180 [ 68.241542][ T8484] bdi_put+0x22/0xa0 [ 68.245439][ T8484] bdev_evict_inode+0x262/0x460 [ 68.250276][ T8484] ? __blkdev_direct_IO_simple+0x930/0x930 [ 68.256081][ T8484] evict+0x2ed/0x6b0 [ 68.259978][ T8484] iput.part.0+0x57e/0x810 [ 68.264378][ T8484] ? find_inode_nowait+0x190/0x190 [ 68.269489][ T8484] iput+0x58/0x70 [ 68.273120][ T8484] dentry_unlink_inode+0x2b1/0x3d0 [ 68.278218][ T8484] __dentry_kill+0x3c0/0x640 [ 68.282805][ T8484] ? dput+0x35/0xbc0 [ 68.286698][ T8484] ? dput+0x35/0xbc0 [ 68.290592][ T8484] dput+0x725/0xbc0 [ 68.294391][ T8484] shrink_dcache_for_umount+0x11f/0x330 [ 68.299932][ T8484] generic_shutdown_super+0x68/0x370 [ 68.305218][ T8484] kill_anon_super+0x36/0x60 [ 68.309883][ T8484] deactivate_locked_super+0x94/0x160 [ 68.315249][ T8484] deactivate_super+0xad/0xd0 [ 68.319910][ T8484] put_fs_context+0xaa/0x650 [ 68.324485][ T8484] ? __sanitizer_cov_trace_const_cmp2+0x22/0x80 [ 68.330714][ T8484] fscontext_release+0x4c/0x60 [ 68.335462][ T8484] __fput+0x283/0x920 [ 68.339443][ T8484] ? fs_validate_description+0x1d0/0x1d0 [ 68.345063][ T8484] task_work_run+0xdd/0x190 [ 68.349558][ T8484] do_exit+0xb89/0x29e0 [ 68.353713][ T8484] ? mm_update_next_owner+0x7a0/0x7a0 [ 68.359066][ T8484] ? __do_sys_fsconfig+0x1c2/0xbd0 [ 68.364162][ T8484] ? fscontext_read+0x310/0x310 [ 68.369000][ T8484] do_group_exit+0x125/0x310 [ 68.373576][ T8484] __x64_sys_exit_group+0x3a/0x50 [ 68.378624][ T8484] do_syscall_64+0x2d/0x70 [ 68.383052][ T8484] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 68.388967][ T8484] RIP: 0033:0x43ee78 [ 68.392876][ T8484] Code: Unable to access opcode bytes at RIP 0x43ee4e. [ 68.399703][ T8484] RSP: 002b:00007ffdc8138ea8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 68.408124][ T8484] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ee78 [ 68.416082][ T8484] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 68.424036][ T8484] RBP: 00000000004be688 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 68.431993][ T8484] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 68.439961][ T8484] R13: 00000000006d0180 R14: 0000000000000000 R15: 0000000000000000 [ 68.447929][ T8484] ================================================================== [ 68.456053][ T8484] Disabling lock debugging due to kernel taint [ 68.463871][ T8484] Kernel panic - not syncing: panic_on_warn set ... [ 68.470475][ T8484] CPU: 0 PID: 8484 Comm: syz-executor868 Tainted: G B 5.10.0-next-20201223-syzkaller #0 [ 68.481519][ T8484] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 68.491552][ T8484] Call Trace: [ 68.494823][ T8484] dump_stack+0x107/0x163 [ 68.499149][ T8484] ? bdi_alloc+0xc0/0x140 [ 68.503460][ T8484] panic+0x306/0x73d [ 68.507337][ T8484] ? __warn_printk+0xf3/0xf3 [ 68.511920][ T8484] ? preempt_schedule_common+0x59/0xc0 [ 68.517362][ T8484] ? bdi_put+0x22/0xa0 [ 68.521407][ T8484] ? preempt_schedule_thunk+0x16/0x18 [ 68.526799][ T8484] ? trace_hardirqs_on+0x38/0x1c0 [ 68.531818][ T8484] ? trace_hardirqs_on+0x51/0x1c0 [ 68.536855][ T8484] ? bdi_put+0x22/0xa0 [ 68.540901][ T8484] ? bdi_put+0x22/0xa0 [ 68.544946][ T8484] end_report+0x58/0x5e [ 68.549115][ T8484] kasan_report.cold+0x67/0xd5 [ 68.553897][ T8484] ? bdi_put+0x22/0xa0 [ 68.557943][ T8484] check_memory_region+0x13d/0x180 [ 68.563037][ T8484] bdi_put+0x22/0xa0 [ 68.566941][ T8484] bdev_evict_inode+0x262/0x460 [ 68.571770][ T8484] ? __blkdev_direct_IO_simple+0x930/0x930 [ 68.577557][ T8484] evict+0x2ed/0x6b0 [ 68.581431][ T8484] iput.part.0+0x57e/0x810 [ 68.585826][ T8484] ? find_inode_nowait+0x190/0x190 [ 68.590918][ T8484] iput+0x58/0x70 [ 68.594544][ T8484] dentry_unlink_inode+0x2b1/0x3d0 [ 68.599642][ T8484] __dentry_kill+0x3c0/0x640 [ 68.604232][ T8484] ? dput+0x35/0xbc0 [ 68.608110][ T8484] ? dput+0x35/0xbc0 [ 68.611987][ T8484] dput+0x725/0xbc0 [ 68.615786][ T8484] shrink_dcache_for_umount+0x11f/0x330 [ 68.621349][ T8484] generic_shutdown_super+0x68/0x370 [ 68.626616][ T8484] kill_anon_super+0x36/0x60 [ 68.631200][ T8484] deactivate_locked_super+0x94/0x160 [ 68.636561][ T8484] deactivate_super+0xad/0xd0 [ 68.641217][ T8484] put_fs_context+0xaa/0x650 [ 68.645798][ T8484] ? __sanitizer_cov_trace_const_cmp2+0x22/0x80 [ 68.652034][ T8484] fscontext_release+0x4c/0x60 [ 68.656799][ T8484] __fput+0x283/0x920 [ 68.660764][ T8484] ? fs_validate_description+0x1d0/0x1d0 [ 68.666379][ T8484] task_work_run+0xdd/0x190 [ 68.670876][ T8484] do_exit+0xb89/0x29e0 [ 68.675022][ T8484] ? mm_update_next_owner+0x7a0/0x7a0 [ 68.680371][ T8484] ? __do_sys_fsconfig+0x1c2/0xbd0 [ 68.685463][ T8484] ? fscontext_read+0x310/0x310 [ 68.690295][ T8484] do_group_exit+0x125/0x310 [ 68.694872][ T8484] __x64_sys_exit_group+0x3a/0x50 [ 68.699875][ T8484] do_syscall_64+0x2d/0x70 [ 68.704277][ T8484] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 68.710156][ T8484] RIP: 0033:0x43ee78 [ 68.714037][ T8484] Code: Unable to access opcode bytes at RIP 0x43ee4e. [ 68.720862][ T8484] RSP: 002b:00007ffdc8138ea8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 68.729256][ T8484] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ee78 [ 68.737211][ T8484] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 68.745162][ T8484] RBP: 00000000004be688 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 68.753114][ T8484] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 68.761064][ T8484] R13: 00000000006d0180 R14: 0000000000000000 R15: 0000000000000000 [ 68.769444][ T8484] Kernel Offset: disabled [ 68.773757][ T8484] Rebooting in 86400 seconds..