[ 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 '10.128.0.47' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 82.829099][ T8487] ================================================================== [ 82.837316][ T8487] BUG: KASAN: null-ptr-deref in bdi_put+0x22/0xa0 [ 82.843736][ T8487] Write of size 4 at addr 0000000000000040 by task syz-executor054/8487 [ 82.852094][ T8487] [ 82.854401][ T8487] CPU: 1 PID: 8487 Comm: syz-executor054 Not tainted 5.10.0-next-20201223-syzkaller #0 [ 82.864010][ T8487] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 82.874050][ T8487] Call Trace: [ 82.877317][ T8487] dump_stack+0x107/0x163 [ 82.881640][ T8487] ? bdi_put+0x22/0xa0 [ 82.885747][ T8487] ? bdi_put+0x22/0xa0 [ 82.889835][ T8487] kasan_report.cold+0x5f/0xd5 [ 82.894588][ T8487] ? bdi_put+0x22/0xa0 [ 82.898643][ T8487] check_memory_region+0x13d/0x180 [ 82.903747][ T8487] bdi_put+0x22/0xa0 [ 82.907637][ T8487] bdev_evict_inode+0x262/0x460 [ 82.912481][ T8487] ? __blkdev_direct_IO_simple+0x930/0x930 [ 82.918273][ T8487] evict+0x2ed/0x6b0 [ 82.922159][ T8487] iput.part.0+0x57e/0x810 [ 82.926568][ T8487] ? find_inode_nowait+0x190/0x190 [ 82.931682][ T8487] iput+0x58/0x70 [ 82.935306][ T8487] dentry_unlink_inode+0x2b1/0x3d0 [ 82.940413][ T8487] __dentry_kill+0x3c0/0x640 [ 82.944996][ T8487] ? dput+0x35/0xbc0 [ 82.948884][ T8487] ? dput+0x35/0xbc0 [ 82.952770][ T8487] dput+0x725/0xbc0 [ 82.956577][ T8487] shrink_dcache_for_umount+0x11f/0x330 [ 82.962122][ T8487] generic_shutdown_super+0x68/0x370 [ 82.967404][ T8487] kill_anon_super+0x36/0x60 [ 82.971986][ T8487] deactivate_locked_super+0x94/0x160 [ 82.977358][ T8487] deactivate_super+0xad/0xd0 [ 82.982035][ T8487] cleanup_mnt+0x3a3/0x530 [ 82.986463][ T8487] task_work_run+0xdd/0x190 [ 82.990964][ T8487] exit_to_user_mode_prepare+0x249/0x250 [ 82.996592][ T8487] syscall_exit_to_user_mode+0x19/0x50 [ 83.002059][ T8487] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 83.007947][ T8487] RIP: 0033:0x440219 [ 83.011843][ T8487] 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 [ 83.031450][ T8487] RSP: 002b:00007fff6b2fbb48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 83.039865][ T8487] RAX: ffffffffffffffea RBX: 0030656c69662f2e RCX: 0000000000440219 [ 83.047827][ T8487] RDX: 00000000200001c0 RSI: 0000000020000300 RDI: 0000000000000000 [ 83.055789][ T8487] RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 [ 83.063747][ T8487] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a20 [ 83.071715][ T8487] R13: 0000000000401ab0 R14: 0000000000000000 R15: 0000000000000000 [ 83.079698][ T8487] ================================================================== [ 83.087739][ T8487] Disabling lock debugging due to kernel taint [ 83.094690][ T8487] Kernel panic - not syncing: panic_on_warn set ... [ 83.101285][ T8487] CPU: 0 PID: 8487 Comm: syz-executor054 Tainted: G B 5.10.0-next-20201223-syzkaller #0 [ 83.112299][ T8487] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 83.122331][ T8487] Call Trace: [ 83.125589][ T8487] dump_stack+0x107/0x163 [ 83.129902][ T8487] ? bdi_alloc+0xc0/0x140 [ 83.134207][ T8487] panic+0x306/0x73d [ 83.138082][ T8487] ? __warn_printk+0xf3/0xf3 [ 83.142649][ T8487] ? preempt_schedule_common+0x59/0xc0 [ 83.148086][ T8487] ? bdi_put+0x22/0xa0 [ 83.152128][ T8487] ? preempt_schedule_thunk+0x16/0x18 [ 83.157482][ T8487] ? trace_hardirqs_on+0x38/0x1c0 [ 83.162485][ T8487] ? trace_hardirqs_on+0x51/0x1c0 [ 83.167490][ T8487] ? bdi_put+0x22/0xa0 [ 83.171533][ T8487] ? bdi_put+0x22/0xa0 [ 83.175612][ T8487] end_report+0x58/0x5e [ 83.179746][ T8487] kasan_report.cold+0x67/0xd5 [ 83.184499][ T8487] ? bdi_put+0x22/0xa0 [ 83.188545][ T8487] check_memory_region+0x13d/0x180 [ 83.193633][ T8487] bdi_put+0x22/0xa0 [ 83.197505][ T8487] bdev_evict_inode+0x262/0x460 [ 83.202333][ T8487] ? __blkdev_direct_IO_simple+0x930/0x930 [ 83.208117][ T8487] evict+0x2ed/0x6b0 [ 83.211995][ T8487] iput.part.0+0x57e/0x810 [ 83.216388][ T8487] ? find_inode_nowait+0x190/0x190 [ 83.221478][ T8487] iput+0x58/0x70 [ 83.225089][ T8487] dentry_unlink_inode+0x2b1/0x3d0 [ 83.230178][ T8487] __dentry_kill+0x3c0/0x640 [ 83.234745][ T8487] ? dput+0x35/0xbc0 [ 83.238620][ T8487] ? dput+0x35/0xbc0 [ 83.242492][ T8487] dput+0x725/0xbc0 [ 83.246280][ T8487] shrink_dcache_for_umount+0x11f/0x330 [ 83.251808][ T8487] generic_shutdown_super+0x68/0x370 [ 83.257075][ T8487] kill_anon_super+0x36/0x60 [ 83.261650][ T8487] deactivate_locked_super+0x94/0x160 [ 83.266999][ T8487] deactivate_super+0xad/0xd0 [ 83.271666][ T8487] cleanup_mnt+0x3a3/0x530 [ 83.276073][ T8487] task_work_run+0xdd/0x190 [ 83.280556][ T8487] exit_to_user_mode_prepare+0x249/0x250 [ 83.286165][ T8487] syscall_exit_to_user_mode+0x19/0x50 [ 83.291602][ T8487] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 83.297476][ T8487] RIP: 0033:0x440219 [ 83.301348][ T8487] 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 [ 83.320943][ T8487] RSP: 002b:00007fff6b2fbb48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 83.329331][ T8487] RAX: ffffffffffffffea RBX: 0030656c69662f2e RCX: 0000000000440219 [ 83.337286][ T8487] RDX: 00000000200001c0 RSI: 0000000020000300 RDI: 0000000000000000 [ 83.345242][ T8487] RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 [ 83.353195][ T8487] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a20 [ 83.361147][ T8487] R13: 0000000000401ab0 R14: 0000000000000000 R15: 0000000000000000 [ 83.369867][ T8487] Kernel Offset: disabled [ 83.374174][ T8487] Rebooting in 86400 seconds..