[ 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. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.94' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 72.986594][ T8488] ================================================================== [ 72.994873][ T8488] BUG: KASAN: null-ptr-deref in bdi_put+0x22/0xa0 [ 73.001319][ T8488] Write of size 4 at addr 0000000000000040 by task syz-executor135/8488 [ 73.009721][ T8488] [ 73.012061][ T8488] CPU: 1 PID: 8488 Comm: syz-executor135 Not tainted 5.11.0-rc2-next-20210107-syzkaller #0 [ 73.022042][ T8488] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 73.032801][ T8488] Call Trace: [ 73.036100][ T8488] dump_stack+0x107/0x163 [ 73.040442][ T8488] ? bdi_put+0x22/0xa0 [ 73.044510][ T8488] ? bdi_put+0x22/0xa0 [ 73.048619][ T8488] kasan_report.cold+0x5f/0xd5 [ 73.053399][ T8488] ? bdi_put+0x22/0xa0 [ 73.057487][ T8488] check_memory_region+0x13d/0x180 [ 73.062650][ T8488] bdi_put+0x22/0xa0 [ 73.066824][ T8488] bdev_evict_inode+0x262/0x460 [ 73.071876][ T8488] ? __blkdev_direct_IO_simple+0x930/0x930 [ 73.077704][ T8488] evict+0x2ed/0x6b0 [ 73.082050][ T8488] iput.part.0+0x57e/0x810 [ 73.086556][ T8488] ? find_inode_nowait+0x190/0x190 [ 73.091804][ T8488] iput+0x58/0x70 [ 73.095585][ T8488] dentry_unlink_inode+0x2b1/0x3d0 [ 73.101198][ T8488] __dentry_kill+0x3c0/0x640 [ 73.105814][ T8488] ? dput+0x35/0xbc0 [ 73.109786][ T8488] ? dput+0x35/0xbc0 [ 73.113697][ T8488] dput+0x725/0xbc0 [ 73.117537][ T8488] shrink_dcache_for_umount+0x11f/0x330 [ 73.123155][ T8488] generic_shutdown_super+0x68/0x370 [ 73.128475][ T8488] kill_anon_super+0x36/0x60 [ 73.133186][ T8488] deactivate_locked_super+0x94/0x160 [ 73.138582][ T8488] deactivate_super+0xad/0xd0 [ 73.143392][ T8488] cleanup_mnt+0x3a3/0x530 [ 73.147831][ T8488] task_work_run+0xdd/0x190 [ 73.152347][ T8488] exit_to_user_mode_prepare+0x249/0x250 [ 73.158006][ T8488] syscall_exit_to_user_mode+0x19/0x50 [ 73.163511][ T8488] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 73.169433][ T8488] RIP: 0033:0x440219 [ 73.173343][ T8488] 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 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 73.193734][ T8488] RSP: 002b:00007fffd643c158 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 73.202413][ T8488] RAX: ffffffffffffffea RBX: 0030656c69662f2e RCX: 0000000000440219 [ 73.210387][ T8488] RDX: 0000000020000040 RSI: 0000000020000140 RDI: 0000000000000000 [ 73.219160][ T8488] RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 [ 73.227129][ T8488] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a20 [ 73.235111][ T8488] R13: 0000000000401ab0 R14: 0000000000000000 R15: 0000000000000000 [ 73.243101][ T8488] ================================================================== [ 73.251149][ T8488] Disabling lock debugging due to kernel taint [ 73.258508][ T8488] Kernel panic - not syncing: panic_on_warn set ... [ 73.265114][ T8488] CPU: 0 PID: 8488 Comm: syz-executor135 Tainted: G B 5.11.0-rc2-next-20210107-syzkaller #0 [ 73.276589][ T8488] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 73.287183][ T8488] Call Trace: [ 73.290453][ T8488] dump_stack+0x107/0x163 [ 73.294784][ T8488] ? bdi_alloc+0xb0/0x140 [ 73.299101][ T8488] panic+0x306/0x73d [ 73.302998][ T8488] ? __warn_printk+0xf3/0xf3 [ 73.307803][ T8488] ? preempt_schedule_common+0x59/0xc0 [ 73.313257][ T8488] ? bdi_put+0x22/0xa0 [ 73.317315][ T8488] ? preempt_schedule_thunk+0x16/0x18 [ 73.322848][ T8488] ? trace_hardirqs_on+0x38/0x1c0 [ 73.327864][ T8488] ? trace_hardirqs_on+0x51/0x1c0 [ 73.333277][ T8488] ? bdi_put+0x22/0xa0 [ 73.337341][ T8488] ? bdi_put+0x22/0xa0 [ 73.341395][ T8488] end_report+0x58/0x5e [ 73.345633][ T8488] kasan_report.cold+0x67/0xd5 [ 73.350385][ T8488] ? bdi_put+0x22/0xa0 [ 73.354526][ T8488] check_memory_region+0x13d/0x180 [ 73.359628][ T8488] bdi_put+0x22/0xa0 [ 73.363507][ T8488] bdev_evict_inode+0x262/0x460 [ 73.368360][ T8488] ? __blkdev_direct_IO_simple+0x930/0x930 [ 73.374157][ T8488] evict+0x2ed/0x6b0 [ 73.378399][ T8488] iput.part.0+0x57e/0x810 [ 73.382804][ T8488] ? find_inode_nowait+0x190/0x190 [ 73.387906][ T8488] iput+0x58/0x70 [ 73.391539][ T8488] dentry_unlink_inode+0x2b1/0x3d0 [ 73.396638][ T8488] __dentry_kill+0x3c0/0x640 [ 73.401393][ T8488] ? dput+0x35/0xbc0 [ 73.405298][ T8488] ? dput+0x35/0xbc0 [ 73.409190][ T8488] dput+0x725/0xbc0 [ 73.413005][ T8488] shrink_dcache_for_umount+0x11f/0x330 [ 73.418546][ T8488] generic_shutdown_super+0x68/0x370 [ 73.424181][ T8488] kill_anon_super+0x36/0x60 [ 73.428796][ T8488] deactivate_locked_super+0x94/0x160 [ 73.434202][ T8488] deactivate_super+0xad/0xd0 [ 73.438985][ T8488] cleanup_mnt+0x3a3/0x530 [ 73.443433][ T8488] task_work_run+0xdd/0x190 [ 73.448043][ T8488] exit_to_user_mode_prepare+0x249/0x250 [ 73.454138][ T8488] syscall_exit_to_user_mode+0x19/0x50 [ 73.459801][ T8488] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 73.465714][ T8488] RIP: 0033:0x440219 [ 73.469616][ T8488] 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 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 73.489417][ T8488] RSP: 002b:00007fffd643c158 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 73.498059][ T8488] RAX: ffffffffffffffea RBX: 0030656c69662f2e RCX: 0000000000440219 [ 73.506049][ T8488] RDX: 0000000020000040 RSI: 0000000020000140 RDI: 0000000000000000 [ 73.514214][ T8488] RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 [ 73.522267][ T8488] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a20 [ 73.530866][ T8488] R13: 0000000000401ab0 R14: 0000000000000000 R15: 0000000000000000 [ 73.539592][ T8488] Kernel Offset: disabled [ 73.543926][ T8488] Rebooting in 86400 seconds..