[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 10.371279] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. [ 11.494237] random: crng init done Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.15' (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 syzkaller login: [ 34.647020] ================================================================== [ 34.648600] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 34.649887] Read of size 8 at addr ffff8801cdde2760 by task blkid/2175 [ 34.651091] [ 34.651432] CPU: 1 PID: 2175 Comm: blkid Not tainted 4.9.128+ #94 [ 34.652703] ffff8801d631f6f8 ffffffff81b2b9e9 ffffea0007377800 ffff8801cdde2760 [ 34.654333] 0000000000000000 ffff8801cdde2760 0000000000000000 ffff8801d631f730 [ 34.655915] ffffffff8150061d ffff8801cdde2760 0000000000000008 0000000000000000 [ 34.657521] Call Trace: [ 34.658015] [] dump_stack+0xc1/0x128 [ 34.659124] [] print_address_description+0x6c/0x234 [ 34.660447] [] kasan_report.cold.6+0x242/0x2fe [ 34.661565] [] ? disk_unblock_events+0x51/0x60 [ 34.662744] [] __asan_report_load8_noabort+0x14/0x20 [ 34.663993] [] disk_unblock_events+0x51/0x60 [ 34.665137] [] __blkdev_get+0x6b6/0xd60 [ 34.666140] [] ? __blkdev_put+0x840/0x840 [ 34.667223] [] ? fsnotify+0x114/0x1100 [ 34.672754] [] blkdev_get+0x2da/0x920 [ 34.678198] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 34.684968] [] ? bd_may_claim+0xd0/0xd0 [ 34.690592] [] ? bd_acquire+0x27/0x250 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.696131] [] ? bd_acquire+0x88/0x250 [ 34.701665] [] ? _raw_spin_unlock+0x2c/0x50 [ 34.707632] [] blkdev_open+0x1a5/0x250 [ 34.713163] [] do_dentry_open+0x3ef/0xc90 [ 34.718955] [] ? blkdev_get_by_dev+0x70/0x70 [ 34.725010] [] vfs_open+0x11c/0x210 [ 34.730281] [] ? may_open.isra.20+0x14f/0x2a0 [ 34.736420] [] path_openat+0x542/0x2790 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.742039] [] ? path_mountpoint+0x6c0/0x6c0 [ 34.748092] [] ? trace_hardirqs_on+0x10/0x10 [ 34.754152] [] ? expand_files.part.3+0x3a9/0x6d0 [ 34.760551] [] do_filp_open+0x197/0x270 [ 34.766197] [] ? may_open_dev+0xe0/0xe0 [ 34.771816] [] ? _raw_spin_unlock+0x2c/0x50 [ 34.777785] [] ? __alloc_fd+0x1d7/0x4a0 [ 34.783411] [] do_sys_open+0x30d/0x5c0 [ 34.788941] [] ? filp_open+0x70/0x70 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.794304] [] ? up_read+0x1a/0x40 [ 34.799500] [] SyS_open+0x2d/0x40 [ 34.804598] [] ? do_sys_open+0x5c0/0x5c0 [ 34.810307] [] do_syscall_64+0x19f/0x550 [ 34.816024] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 34.822937] [ 34.824554] Allocated by task 2169: [ 34.828178] save_stack_trace+0x16/0x20 [ 34.832146] kasan_kmalloc.part.1+0x62/0xf0 [ 34.836459] kasan_kmalloc+0xaf/0xc0 [ 34.840167] kmem_cache_alloc_trace+0x117/0x2e0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.844834] alloc_disk_node+0x54/0x3a0 [ 34.848799] alloc_disk+0x18/0x20 [ 34.852249] loop_add+0x33b/0x770 [ 34.855695] loop_probe+0x14f/0x180 [ 34.859319] kobj_lookup+0x223/0x410 [ 34.863038] get_gendisk+0x39/0x2d0 [ 34.866659] __blkdev_get+0x351/0xd60 [ 34.870454] blkdev_get+0x488/0x920 [ 34.874073] blkdev_open+0x1a5/0x250 [ 34.877787] do_dentry_open+0x3ef/0xc90 [ 34.881755] vfs_open+0x11c/0x210 [ 34.885206] path_openat+0x542/0x2790 [ 34.889030] do_filp_open+0x197/0x270 [ 34.892827] do_sys_open+0x30d/0x5c0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.896536] SyS_open+0x2d/0x40 [ 34.899815] do_syscall_64+0x19f/0x550 [ 34.903698] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 34.908787] [ 34.910419] Freed by task 2175: [ 34.913704] save_stack_trace+0x16/0x20 [ 34.917670] kasan_slab_free+0xac/0x190 [ 34.921636] kfree+0xfb/0x310 [ 34.924735] disk_release+0x259/0x330 [ 34.928534] device_release+0x7e/0x220 [ 34.932413] kobject_put+0x148/0x250 [ 34.936125] put_disk+0x23/0x30 [ 34.939430] __blkdev_get+0x616/0xd60 [ 34.943221] blkdev_get+0x2da/0x920 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.946838] blkdev_open+0x1a5/0x250 [ 34.950547] do_dentry_open+0x3ef/0xc90 [ 34.954512] vfs_open+0x11c/0x210 [ 34.957962] path_openat+0x542/0x2790 [ 34.961754] do_filp_open+0x197/0x270 [ 34.965550] do_sys_open+0x30d/0x5c0 [ 34.969253] SyS_open+0x2d/0x40 [ 34.972543] do_syscall_64+0x19f/0x550 [ 34.976427] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 34.981513] [ 34.983137] The buggy address belongs to the object at ffff8801cdde2200 [ 34.983137] which belongs to the cache kmalloc-2048 of size 2048 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.995959] The buggy address is located 1376 bytes inside of [ 34.995959] 2048-byte region [ffff8801cdde2200, ffff8801cdde2a00) [ 35.007995] The buggy address belongs to the page: [ 35.012915] page:ffffea0007377800 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 35.023141] flags: 0x4000000000004080(slab|head) [ 35.027885] page dumped because: kasan: bad access detected [ 35.033880] [ 35.035502] Memory state around the buggy address: [ 35.040419] ffff8801cdde2600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 35.047769] ffff8801cdde2680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 35.055125] >ffff8801cdde2700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 35.062473] ^ [ 35.068958] ffff8801cdde2780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 35.076307] ffff8801cdde2800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 35.083684] ================================================================== [ 35.091032] Disabling lock debugging due to kernel taint executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 35.102361] Kernel panic - not syncing: panic_on_warn set ... [ 35.102361] [ 35.109736] CPU: 1 PID: 2175 Comm: blkid Tainted: G B 4.9.128+ #94 [ 35.117170] ffff8801d631f658 ffffffff81b2b9e9 ffffffff82e349c0 00000000ffffffff [ 35.125206] 0000000000000000 0000000000000001 0000000000000000 ffff8801d631f718 [ 35.133310] ffffffff813f6665 0000000041b58ab3 ffffffff82e289c3 ffffffff813f64a6 [ 35.141370] Call Trace: [ 35.143944] [] dump_stack+0xc1/0x128 [ 35.149328] [] panic+0x1bf/0x39f [ 35.154359] [] ? add_taint.cold.6+0x16/0x16 [ 35.160325] [] ? ___preempt_schedule+0x16/0x18 [ 35.167041] [] kasan_end_report+0x47/0x4f [ 35.172836] [] kasan_report.cold.6+0x76/0x2fe [ 35.178977] [] ? disk_unblock_events+0x51/0x60 [ 35.185206] [] __asan_report_load8_noabort+0x14/0x20 [ 35.191950] [] disk_unblock_events+0x51/0x60 [ 35.198004] [] __blkdev_get+0x6b6/0xd60 [ 35.203620] [] ? __blkdev_put+0x840/0x840 [ 35.209416] [] ? fsnotify+0x114/0x1100 [ 35.214942] [] blkdev_get+0x2da/0x920 [ 35.220388] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 35.227136] [] ? bd_may_claim+0xd0/0xd0 [ 35.232758] [] ? bd_acquire+0x27/0x250 [ 35.238293] [] ? bd_acquire+0x88/0x250 [ 35.243828] [] ? _raw_spin_unlock+0x2c/0x50 [ 35.249794] [] blkdev_open+0x1a5/0x250 [ 35.255326] [] do_dentry_open+0x3ef/0xc90 [ 35.261135] [] ? blkdev_get_by_dev+0x70/0x70 [ 35.267201] [] vfs_open+0x11c/0x210 [ 35.272488] [] ? may_open.isra.20+0x14f/0x2a0 [ 35.278623] [] path_openat+0x542/0x2790 [ 35.284237] [] ? path_mountpoint+0x6c0/0x6c0 [ 35.290321] [] ? trace_hardirqs_on+0x10/0x10 [ 35.296400] [] ? expand_files.part.3+0x3a9/0x6d0 [ 35.302800] [] do_filp_open+0x197/0x270 [ 35.308420] [] ? may_open_dev+0xe0/0xe0 [ 35.314039] [] ? _raw_spin_unlock+0x2c/0x50 [ 35.320006] [] ? __alloc_fd+0x1d7/0x4a0 [ 35.325682] [] do_sys_open+0x30d/0x5c0 [ 35.331213] [] ? filp_open+0x70/0x70 [ 35.336577] [] ? up_read+0x1a/0x40 [ 35.341763] [] SyS_open+0x2d/0x40 [ 35.346861] [] ? do_sys_open+0x5c0/0x5c0 [ 35.352567] [] do_syscall_64+0x19f/0x550 [ 35.358276] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 35.365512] Kernel Offset: disabled [ 35.369129] Rebooting in 86400 seconds..