[....] 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[ 10.227702] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 38.698674] random: sshd: uninitialized urandom read (32 bytes read) [ 38.727362] random: crng init done Warning: Permanently added '10.128.0.101' (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 [ 46.477471] ================================================================== [ 46.484916] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 46.491673] Read of size 8 at addr ffff8801cad20560 by task blkid/2376 [ 46.498331] [ 46.499946] CPU: 1 PID: 2376 Comm: blkid Not tainted 4.9.135+ #61 [ 46.506289] ffff8801ca7ef6f8 ffffffff81b36bf9 ffffea00072b4800 ffff8801cad20560 [ 46.514408] 0000000000000000 ffff8801cad20560 0000000000000000 ffff8801ca7ef730 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 46.522504] ffffffff815009ad ffff8801cad20560 0000000000000008 0000000000000000 [ 46.530588] Call Trace: [ 46.533202] [] dump_stack+0xc1/0x128 [ 46.538583] [] print_address_description+0x6c/0x234 [ 46.545271] [] kasan_report.cold.6+0x242/0x2fe [ 46.551699] [] ? disk_unblock_events+0x51/0x60 [ 46.557951] [] __asan_report_load8_noabort+0x14/0x20 [ 46.564826] [] disk_unblock_events+0x51/0x60 [ 46.570910] [] __blkdev_get+0x6b6/0xd60 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 46.576549] [] ? __blkdev_put+0x840/0x840 [ 46.582369] [] ? fsnotify+0x114/0x1100 [ 46.587926] [] blkdev_get+0x2da/0x920 [ 46.593389] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 46.600152] [] ? bd_may_claim+0xd0/0xd0 [ 46.605795] [] ? bd_acquire+0x27/0x250 [ 46.611346] [] ? bd_acquire+0x88/0x250 [ 46.616907] [] ? _raw_spin_unlock+0x2c/0x50 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 46.622894] [] blkdev_open+0x1a5/0x250 [ 46.628533] [] do_dentry_open+0x3ef/0xc90 [ 46.634344] [] ? blkdev_get_by_dev+0x70/0x70 [ 46.640421] [] vfs_open+0x11c/0x210 [ 46.645720] [] ? may_open.isra.20+0x14f/0x2a0 [ 46.651884] [] path_openat+0x542/0x2790 [ 46.657531] [] ? path_mountpoint+0x6c0/0x6c0 [ 46.663604] [] ? trace_hardirqs_on+0x10/0x10 [ 46.669690] [] ? expand_files.part.3+0x3a9/0x6d0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 46.676117] [] do_filp_open+0x197/0x270 [ 46.681752] [] ? may_open_dev+0xe0/0xe0 [ 46.687394] [] ? _raw_spin_unlock+0x2c/0x50 [ 46.693379] [] ? __alloc_fd+0x1d7/0x4a0 [ 46.699120] [] do_sys_open+0x30d/0x5c0 [ 46.704670] [] ? filp_open+0x70/0x70 [ 46.710057] [] ? up_read+0x1a/0x40 [ 46.715267] [] SyS_open+0x2d/0x40 [ 46.720376] [] ? do_sys_open+0x5c0/0x5c0 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 46.726106] [] do_syscall_64+0x19f/0x550 [ 46.731825] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 46.738751] [ 46.740382] Allocated by task 2345: [ 46.744020] save_stack_trace+0x16/0x20 [ 46.748018] kasan_kmalloc.part.1+0x62/0xf0 [ 46.752346] kasan_kmalloc+0xaf/0xc0 [ 46.756067] kmem_cache_alloc_trace+0x117/0x2e0 [ 46.760748] alloc_disk_node+0x54/0x3a0 [ 46.764725] alloc_disk+0x18/0x20 [ 46.768182] loop_add+0x368/0x7a0 [ 46.771638] loop_probe+0x14f/0x180 [ 46.775268] kobj_lookup+0x223/0x410 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 46.778983] get_gendisk+0x39/0x2d0 [ 46.782611] __blkdev_get+0x351/0xd60 [ 46.786416] blkdev_get+0x488/0x920 [ 46.790059] blkdev_open+0x1a5/0x250 [ 46.793789] do_dentry_open+0x3ef/0xc90 [ 46.797763] vfs_open+0x11c/0x210 [ 46.801218] path_openat+0x542/0x2790 [ 46.805025] do_filp_open+0x197/0x270 [ 46.808835] do_sys_open+0x30d/0x5c0 [ 46.812551] SyS_open+0x2d/0x40 [ 46.815846] do_syscall_64+0x19f/0x550 [ 46.819735] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 46.824827] executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 46.826448] Freed by task 2376: [ 46.829734] save_stack_trace+0x16/0x20 [ 46.833715] kasan_slab_free+0xac/0x190 [ 46.837695] kfree+0xfb/0x310 [ 46.840809] disk_release+0x259/0x330 [ 46.844616] device_release+0x7e/0x220 [ 46.848505] kobject_put+0x148/0x250 [ 46.852230] put_disk+0x23/0x30 [ 46.855524] __blkdev_get+0x616/0xd60 [ 46.859324] blkdev_get+0x2da/0x920 [ 46.862954] blkdev_open+0x1a5/0x250 [ 46.866671] do_dentry_open+0x3ef/0xc90 [ 46.870654] vfs_open+0x11c/0x210 [ 46.874111] 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 46.877908] do_filp_open+0x197/0x270 [ 46.881710] do_sys_open+0x30d/0x5c0 [ 46.885421] SyS_open+0x2d/0x40 [ 46.888701] do_syscall_64+0x19f/0x550 [ 46.892592] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 46.897689] [ 46.899318] The buggy address belongs to the object at ffff8801cad20000 [ 46.899318] which belongs to the cache kmalloc-2048 of size 2048 [ 46.912165] The buggy address is located 1376 bytes inside of [ 46.912165] 2048-byte region [ffff8801cad20000, ffff8801cad20800) [ 46.924215] The buggy address belongs to the page: executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 46.929146] page:ffffea00072b4800 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 46.939400] flags: 0x4000000000004080(slab|head) [ 46.944150] page dumped because: kasan: bad access detected [ 46.949860] [ 46.951481] Memory state around the buggy address: [ 46.956415] ffff8801cad20400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.963861] ffff8801cad20480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.971225] >ffff8801cad20500: 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 46.978586] ^ [ 46.985086] ffff8801cad20580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.992454] ffff8801cad20600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.999817] ================================================================== [ 47.007183] Disabling lock debugging due to kernel taint [ 47.013778] Kernel panic - not syncing: panic_on_warn set ... [ 47.013778] [ 47.021161] CPU: 1 PID: 2376 Comm: blkid Tainted: G B 4.9.135+ #61 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 47.028605] ffff8801ca7ef658 ffffffff81b36bf9 ffffffff82e366e0 00000000ffffffff [ 47.036711] 0000000000000000 0000000000000001 0000000000000000 ffff8801ca7ef718 [ 47.044802] ffffffff813f6aa5 0000000041b58ab3 ffffffff82e2a6e3 ffffffff813f68e6 [ 47.052871] Call Trace: [ 47.055474] [] dump_stack+0xc1/0x128 [ 47.060839] [] panic+0x1bf/0x39f [ 47.065859] [] ? add_taint.cold.6+0x16/0x16 [ 47.071838] [] ? ___preempt_schedule+0x16/0x18 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 47.078089] [] kasan_end_report+0x47/0x4f [ 47.083896] [] kasan_report.cold.6+0x76/0x2fe [ 47.090060] [] ? disk_unblock_events+0x51/0x60 [ 47.096306] [] __asan_report_load8_noabort+0x14/0x20 [ 47.103085] [] disk_unblock_events+0x51/0x60 [ 47.109156] [] __blkdev_get+0x6b6/0xd60 [ 47.114789] [] ? __blkdev_put+0x840/0x840 [ 47.120612] [] ? fsnotify+0x114/0x1100 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 47.126176] [] blkdev_get+0x2da/0x920 [ 47.131642] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 47.138409] [] ? bd_may_claim+0xd0/0xd0 [ 47.144039] [] ? bd_acquire+0x27/0x250 [ 47.149604] [] ? bd_acquire+0x88/0x250 [ 47.155138] [] ? _raw_spin_unlock+0x2c/0x50 [ 47.161194] [] blkdev_open+0x1a5/0x250 [ 47.166737] [] do_dentry_open+0x3ef/0xc90 [ 47.172543] [] ? blkdev_get_by_dev+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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 47.178612] [] vfs_open+0x11c/0x210 [ 47.183902] [] ? may_open.isra.20+0x14f/0x2a0 [ 47.190141] [] path_openat+0x542/0x2790 [ 47.195893] [] ? path_mountpoint+0x6c0/0x6c0 [ 47.201960] [] ? trace_hardirqs_on+0x10/0x10 [ 47.208027] [] ? expand_files.part.3+0x3a9/0x6d0 [ 47.214445] [] do_filp_open+0x197/0x270 [ 47.220082] [] ? may_open_dev+0xe0/0xe0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 47.225711] [] ? _raw_spin_unlock+0x2c/0x50 [ 47.231690] [] ? __alloc_fd+0x1d7/0x4a0 [ 47.237308] [] do_sys_open+0x30d/0x5c0 [ 47.242845] [] ? filp_open+0x70/0x70 [ 47.248210] [] ? up_read+0x1a/0x40 [ 47.253404] [] SyS_open+0x2d/0x40 [ 47.258509] [] ? do_sys_open+0x5c0/0x5c0 [ 47.264228] [] do_syscall_64+0x19f/0x550 [ 47.269937] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 47.277326] Kernel Offset: disabled [ 47.280945] Rebooting in 86400 seconds..