INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added 'ci-upstream-mmots-kasan-gce-3,10.128.15.208' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 51.326224] ================================================================== [ 51.327400] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 51.328395] Read of size 8 at addr ffff8801ca1269c0 by task blkid/11961 [ 51.329346] [ 51.329608] CPU: 0 PID: 11961 Comm: blkid Not tainted 4.14.0-rc5-mm1+ #20 [ 51.330669] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.332407] Call Trace: [ 51.332769] dump_stack+0x194/0x257 [ 51.333261] ? arch_local_irq_restore+0x53/0x53 [ 51.333889] ? show_regs_print_info+0x65/0x65 [ 51.334516] ? kfree_const+0x31/0x40 [ 51.335025] ? disk_unblock_events+0x51/0x60 [ 51.335620] print_address_description+0x73/0x250 [ 51.336266] ? disk_unblock_events+0x51/0x60 [ 51.336855] kasan_report+0x25b/0x340 [ 51.337389] __asan_report_load8_noabort+0x14/0x20 [ 51.338046] disk_unblock_events+0x51/0x60 [ 51.338628] __blkdev_get+0x78d/0xf90 [ 51.339164] ? __blkdev_put+0x7c0/0x7c0 [ 51.339745] blkdev_get+0x3a1/0xad0 [ 51.340255] ? do_raw_spin_trylock+0x190/0x190 [ 51.340869] ? bd_link_disk_holder+0x8b0/0x8b0 [ 51.341484] ? __fsnotify_parent+0xb4/0x3a0 [ 51.342066] ? errseq_sample+0xee/0x140 [ 51.342599] ? _copy_to_user+0xc0/0xc0 [ 51.343163] ? _raw_spin_unlock+0x22/0x30 [ 51.343751] blkdev_open+0x1c9/0x250 [ 51.344271] ? security_file_open+0x89/0x190 [ 51.344884] do_dentry_open+0x664/0xd40 [ 51.345445] ? security_inode_permission+0xbb/0xf0 [ 51.346109] ? bd_acquire+0x2c0/0x2c0 [ 51.348355] vfs_open+0x107/0x220 [ 51.351796] path_openat+0x1151/0x3520 [ 51.355671] ? path_lookupat+0xba0/0xba0 [ 51.359705] ? lock_downgrade+0x990/0x990 [ 51.363829] ? do_sys_open+0x2e7/0x6d0 [ 51.367711] ? do_raw_spin_trylock+0x190/0x190 [ 51.372290] ? __lock_is_held+0xb6/0x140 executing program executing program [ 51.376330] ? _find_next_bit+0xee/0x120 [ 51.380387] ? _raw_spin_unlock+0x22/0x30 [ 51.384531] ? __alloc_fd+0x29b/0x750 [ 51.388344] do_filp_open+0x25b/0x3b0 [ 51.392138] ? may_open_dev+0xe0/0xe0 [ 51.395944] ? mpi_resize+0x200/0x200 [ 51.399739] ? get_unused_fd_flags+0x121/0x190 [ 51.404312] ? getname_flags+0x256/0x580 [ 51.408472] do_sys_open+0x502/0x6d0 [ 51.412170] ? do_sys_open+0x502/0x6d0 [ 51.416053] ? filp_open+0x70/0x70 [ 51.419579] ? entry_SYSCALL_64_fastpath+0x5/0xbe executing program executing program executing program executing program [ 51.424411] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 51.429423] SyS_open+0x2d/0x40 [ 51.432695] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 51.437433] RIP: 0033:0x7f8b7be36120 [ 51.441137] RSP: 002b:00007fff0e5989b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 51.448830] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8b7be36120 [ 51.456095] RDX: 00007fff0e59af35 RSI: 0000000000000000 RDI: 00007fff0e59af35 [ 51.463360] RBP: 0000000000000082 R08: 0000000000000078 R09: 0000000000000000 [ 51.470620] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000403738 [ 51.477899] R13: 0000000000000001 R14: 0000000000000000 R15: 00007f8b7c10ca20 [ 51.485186] [ 51.486797] Allocated by task 11973: [ 51.490504] save_stack+0x43/0xd0 [ 51.493950] kasan_kmalloc+0xad/0xe0 [ 51.497655] kmem_cache_alloc_node_trace+0x150/0x750 [ 51.502739] alloc_disk_node+0xb4/0x4e0 [ 51.506681] alloc_disk+0x18/0x20 [ 51.510107] loop_add+0x45c/0xa50 [ 51.513526] loop_probe+0x16d/0x1a0 [ 51.517124] kobj_lookup+0x2ac/0x410 [ 51.520808] get_gendisk+0x37/0x230 [ 51.524403] blkdev_get+0x12d/0xad0 [ 51.527996] blkdev_open+0x1c9/0x250 [ 51.531692] do_dentry_open+0x664/0xd40 [ 51.535635] vfs_open+0x107/0x220 [ 51.539066] path_openat+0x1151/0x3520 [ 51.542928] do_filp_open+0x25b/0x3b0 [ 51.546702] do_sys_open+0x502/0x6d0 [ 51.550407] SyS_open+0x2d/0x40 [ 51.553656] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 51.558384] [ 51.559980] Freed by task 11961: [ 51.563321] save_stack+0x43/0xd0 [ 51.566742] kasan_slab_free+0x71/0xc0 [ 51.570599] kfree+0xca/0x250 [ 51.573676] disk_release+0x327/0x410 [ 51.577446] device_release+0x7c/0x200 [ 51.581302] kobject_put+0x14c/0x240 [ 51.584993] put_disk+0x23/0x30 [ 51.588252] __blkdev_get+0x6ed/0xf90 [ 51.592030] blkdev_get+0x3a1/0xad0 [ 51.595628] blkdev_open+0x1c9/0x250 [ 51.599319] do_dentry_open+0x664/0xd40 [ 51.603262] vfs_open+0x107/0x220 [ 51.606681] path_openat+0x1151/0x3520 [ 51.610536] do_filp_open+0x25b/0x3b0 [ 51.614302] do_sys_open+0x502/0x6d0 [ 51.617982] SyS_open+0x2d/0x40 [ 51.621230] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 51.625951] [ 51.627560] The buggy address belongs to the object at ffff8801ca126440 [ 51.627560] which belongs to the cache kmalloc-2048 of size 2048 [ 51.640454] The buggy address is located 1408 bytes inside of [ 51.640454] 2048-byte region [ffff8801ca126440, ffff8801ca126c40) [ 51.652469] The buggy address belongs to the page: [ 51.657373] page:ffffea0007284980 count:1 mapcount:0 mapping:ffff8801ca126440 index:0x0 compound_mapcount: 0 [ 51.667320] flags: 0x200000000008100(slab|head) [ 51.671973] raw: 0200000000008100 ffff8801ca126440 0000000000000000 0000000100000003 [ 51.679837] raw: ffffea0007284920 ffffea000729a120 ffff8801dac00c40 0000000000000000 [ 51.687692] page dumped because: kasan: bad access detected [ 51.693373] [ 51.694968] Memory state around the buggy address: [ 51.699864] ffff8801ca126880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.707204] ffff8801ca126900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.714539] >ffff8801ca126980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.721870] ^ executing program [ 51.727287] ffff8801ca126a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.734623] ffff8801ca126a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.741948] ================================================================== [ 51.749278] Disabling lock debugging due to kernel taint [ 51.754789] Kernel panic - not syncing: panic_on_warn set ... [ 51.754789] [ 51.762132] CPU: 0 PID: 11961 Comm: blkid Tainted: G B 4.14.0-rc5-mm1+ #20 [ 51.770329] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.779657] Call Trace: [ 51.782221] dump_stack+0x194/0x257 [ 51.785822] ? arch_local_irq_restore+0x53/0x53 [ 51.790473] ? kasan_end_report+0x32/0x50 [ 51.794598] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 51.799322] ? vsnprintf+0x1ed/0x1900 [ 51.803100] ? del_gendisk+0x920/0x950 [ 51.806963] panic+0x1e4/0x41c [ 51.810124] ? refcount_error_report+0x214/0x214 [ 51.814847] ? add_taint+0x1c/0x50 [ 51.818364] ? add_taint+0x1c/0x50 [ 51.821892] ? disk_unblock_events+0x51/0x60 [ 51.826279] kasan_end_report+0x50/0x50 [ 51.830238] kasan_report+0x144/0x340 [ 51.834013] __asan_report_load8_noabort+0x14/0x20 [ 51.838920] disk_unblock_events+0x51/0x60 [ 51.843130] __blkdev_get+0x78d/0xf90 [ 51.846914] ? __blkdev_put+0x7c0/0x7c0 [ 51.850873] blkdev_get+0x3a1/0xad0 [ 51.854577] ? do_raw_spin_trylock+0x190/0x190 [ 51.859155] ? bd_link_disk_holder+0x8b0/0x8b0 [ 51.863709] ? __fsnotify_parent+0xb4/0x3a0 [ 51.867998] ? errseq_sample+0xee/0x140 [ 51.871942] ? _copy_to_user+0xc0/0xc0 [ 51.875807] ? _raw_spin_unlock+0x22/0x30 [ 51.879923] blkdev_open+0x1c9/0x250 [ 51.883607] ? security_file_open+0x89/0x190 [ 51.887988] do_dentry_open+0x664/0xd40 [ 51.891932] ? security_inode_permission+0xbb/0xf0 [ 51.896829] ? bd_acquire+0x2c0/0x2c0 [ 51.900600] vfs_open+0x107/0x220 [ 51.904028] path_openat+0x1151/0x3520 [ 51.907896] ? path_lookupat+0xba0/0xba0 [ 51.911927] ? lock_downgrade+0x990/0x990 [ 51.916043] ? do_sys_open+0x2e7/0x6d0 [ 51.919902] ? do_raw_spin_trylock+0x190/0x190 [ 51.924455] ? __lock_is_held+0xb6/0x140 [ 51.928485] ? _find_next_bit+0xee/0x120 [ 51.932517] ? _raw_spin_unlock+0x22/0x30 [ 51.936631] ? __alloc_fd+0x29b/0x750 [ 51.940403] do_filp_open+0x25b/0x3b0 [ 51.944172] ? may_open_dev+0xe0/0xe0 [ 51.947954] ? mpi_resize+0x200/0x200 [ 51.951723] ? get_unused_fd_flags+0x121/0x190 [ 51.956276] ? getname_flags+0x256/0x580 [ 51.960305] do_sys_open+0x502/0x6d0 [ 51.963985] ? do_sys_open+0x502/0x6d0 [ 51.967838] ? filp_open+0x70/0x70 [ 51.971347] ? entry_SYSCALL_64_fastpath+0x5/0xbe [ 51.976159] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 51.981146] SyS_open+0x2d/0x40 [ 51.984408] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 51.989134] RIP: 0033:0x7f8b7be36120 [ 51.992817] RSP: 002b:00007fff0e5989b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 52.000497] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8b7be36120 [ 52.007735] RDX: 00007fff0e59af35 RSI: 0000000000000000 RDI: 00007fff0e59af35 [ 52.014973] RBP: 0000000000000082 R08: 0000000000000078 R09: 0000000000000000 [ 52.022208] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000403738 [ 52.029442] R13: 0000000000000001 R14: 0000000000000000 R15: 00007f8b7c10ca20 [ 52.037163] Dumping ftrace buffer: [ 52.040670] (ftrace buffer empty) [ 52.044345] Kernel Offset: disabled [ 52.047941] Rebooting in 86400 seconds..