[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ 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. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.67' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 71.657352][ T8507] ================================================================== [ 71.665547][ T8507] BUG: KASAN: null-ptr-deref in bdi_put+0x22/0xa0 [ 71.671980][ T8507] Write of size 4 at addr 0000000000000040 by task syz-executor742/8507 [ 71.680319][ T8507] [ 71.682663][ T8507] CPU: 1 PID: 8507 Comm: syz-executor742 Not tainted 5.10.0-rc7-next-20201210-syzkaller #0 [ 71.692630][ T8507] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 71.702695][ T8507] Call Trace: [ 71.705986][ T8507] dump_stack+0x107/0x163 [ 71.710351][ T8507] ? bdi_put+0x22/0xa0 [ 71.714431][ T8507] ? bdi_put+0x22/0xa0 [ 71.718513][ T8507] kasan_report.cold+0x5f/0xd5 [ 71.723298][ T8507] ? bdi_put+0x22/0xa0 [ 71.727386][ T8507] check_memory_region+0x13d/0x180 [ 71.732685][ T8507] bdi_put+0x22/0xa0 [ 71.736601][ T8507] bdev_evict_inode+0x280/0x4a0 [ 71.741465][ T8507] ? __blkdev_direct_IO_simple+0x930/0x930 [ 71.747286][ T8507] evict+0x2ed/0x6b0 [ 71.751205][ T8507] iput.part.0+0x41e/0x840 [ 71.755655][ T8507] ? __remove_inode_hash+0x130/0x130 [ 71.760963][ T8507] iput+0x58/0x70 [ 71.764612][ T8507] dentry_unlink_inode+0x2b1/0x3d0 [ 71.769755][ T8507] __dentry_kill+0x3c0/0x640 [ 71.774974][ T8507] ? dput+0x35/0xc10 [ 71.778880][ T8507] ? dput+0x35/0xc10 [ 71.782804][ T8507] dput+0x786/0xc10 [ 71.786654][ T8507] shrink_dcache_for_umount+0x11f/0x330 [ 71.792236][ T8507] generic_shutdown_super+0x68/0x370 [ 71.797547][ T8507] kill_anon_super+0x36/0x60 [ 71.802159][ T8507] deactivate_locked_super+0x94/0x160 [ 71.807552][ T8507] deactivate_super+0xad/0xd0 [ 71.812272][ T8507] cleanup_mnt+0x3a3/0x530 [ 71.816737][ T8507] task_work_run+0xdd/0x190 [ 71.821266][ T8507] exit_to_user_mode_prepare+0x1f0/0x200 [ 71.826918][ T8507] syscall_exit_to_user_mode+0x19/0x50 [ 71.832395][ T8507] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 71.838318][ T8507] RIP: 0033:0x4406c9 [ 71.842225][ T8507] 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 cb 11 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 71.861848][ T8507] RSP: 002b:00007ffcbdf93508 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 71.870283][ T8507] RAX: ffffffffffffffea RBX: 00000000004a1d58 RCX: 00000000004406c9 [ 71.878276][ T8507] RDX: 00000000200001c0 RSI: 0000000020000300 RDI: 0000000000000000 [ 71.886268][ T8507] RBP: 00000000004a1b98 R08: 0000000000000000 R09: 0000000000401d20 [ 71.894276][ T8507] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401d20 [ 71.902275][ T8507] R13: 0000000000401db0 R14: 0000000000000000 R15: 0000000000000000 [ 71.910304][ T8507] ================================================================== [ 71.918381][ T8507] Disabling lock debugging due to kernel taint [ 71.927589][ T8507] Kernel panic - not syncing: panic_on_warn set ... [ 71.934190][ T8507] CPU: 1 PID: 8507 Comm: syz-executor742 Tainted: G B 5.10.0-rc7-next-20201210-syzkaller #0 [ 71.945567][ T8507] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 71.955632][ T8507] Call Trace: [ 71.958917][ T8507] dump_stack+0x107/0x163 [ 71.963258][ T8507] panic+0x343/0x77f [ 71.967171][ T8507] ? __warn_printk+0xf3/0xf3 [ 71.971767][ T8507] ? preempt_schedule_common+0x59/0xc0 [ 71.977934][ T8507] ? bdi_put+0x22/0xa0 [ 71.982014][ T8507] ? preempt_schedule_thunk+0x16/0x18 [ 71.987399][ T8507] ? trace_hardirqs_on+0x38/0x1c0 [ 71.992430][ T8507] ? trace_hardirqs_on+0x51/0x1c0 [ 71.997463][ T8507] ? bdi_put+0x22/0xa0 [ 72.001538][ T8507] ? bdi_put+0x22/0xa0 [ 72.005611][ T8507] end_report+0x58/0x5e [ 72.009775][ T8507] kasan_report.cold+0x67/0xd5 [ 72.014564][ T8507] ? bdi_put+0x22/0xa0 [ 72.018645][ T8507] check_memory_region+0x13d/0x180 [ 72.023763][ T8507] bdi_put+0x22/0xa0 [ 72.027668][ T8507] bdev_evict_inode+0x280/0x4a0 [ 72.032525][ T8507] ? __blkdev_direct_IO_simple+0x930/0x930 [ 72.038358][ T8507] evict+0x2ed/0x6b0 [ 72.042271][ T8507] iput.part.0+0x41e/0x840 [ 72.046729][ T8507] ? __remove_inode_hash+0x130/0x130 [ 72.052050][ T8507] iput+0x58/0x70 [ 72.055695][ T8507] dentry_unlink_inode+0x2b1/0x3d0 [ 72.060818][ T8507] __dentry_kill+0x3c0/0x640 [ 72.065424][ T8507] ? dput+0x35/0xc10 [ 72.069328][ T8507] ? dput+0x35/0xc10 [ 72.073230][ T8507] dput+0x786/0xc10 [ 72.077053][ T8507] shrink_dcache_for_umount+0x11f/0x330 [ 72.082615][ T8507] generic_shutdown_super+0x68/0x370 [ 72.087921][ T8507] kill_anon_super+0x36/0x60 [ 72.092532][ T8507] deactivate_locked_super+0x94/0x160 [ 72.097919][ T8507] deactivate_super+0xad/0xd0 [ 72.102609][ T8507] cleanup_mnt+0x3a3/0x530 [ 72.107042][ T8507] task_work_run+0xdd/0x190 [ 72.111564][ T8507] exit_to_user_mode_prepare+0x1f0/0x200 [ 72.117215][ T8507] syscall_exit_to_user_mode+0x19/0x50 [ 72.122681][ T8507] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 72.128585][ T8507] RIP: 0033:0x4406c9 [ 72.132480][ T8507] 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 cb 11 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 72.152097][ T8507] RSP: 002b:00007ffcbdf93508 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 72.160528][ T8507] RAX: ffffffffffffffea RBX: 00000000004a1d58 RCX: 00000000004406c9 [ 72.168508][ T8507] RDX: 00000000200001c0 RSI: 0000000020000300 RDI: 0000000000000000 [ 72.176501][ T8507] RBP: 00000000004a1b98 R08: 0000000000000000 R09: 0000000000401d20 [ 72.184476][ T8507] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401d20 [ 72.192452][ T8507] R13: 0000000000401db0 R14: 0000000000000000 R15: 0000000000000000 [ 72.200960][ T8507] Kernel Offset: disabled [ 72.205280][ T8507] Rebooting in 86400 seconds..