[....] 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[ 10.984748] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 25.568548] random: sshd: uninitialized urandom read (32 bytes read) [ 25.630791] random: crng init done Warning: Permanently added '10.128.10.53' (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 [ 39.288463] ================================================================== [ 39.296102] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 39.303173] Read of size 8 at addr ffff8801c7fc0560 by task blkid/2418 [ 39.310198] [ 39.311848] CPU: 1 PID: 2418 Comm: blkid Not tainted 4.9.141+ #1 [ 39.317985] ffff8801c78cf6f8 ffffffff81b42e79 ffffea00071ff000 ffff8801c7fc0560 [ 39.326689] 0000000000000000 ffff8801c7fc0560 0000000000000000 ffff8801c78cf730 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 39.334949] ffffffff815009b8 ffff8801c7fc0560 0000000000000008 0000000000000000 [ 39.343056] Call Trace: [ 39.345769] [] dump_stack+0xc1/0x128 [ 39.351133] [] print_address_description+0x6c/0x234 [ 39.357919] [] kasan_report.cold.6+0x242/0x2fe [ 39.364293] [] ? disk_unblock_events+0x51/0x60 [ 39.370690] [] __asan_report_load8_noabort+0x14/0x20 [ 39.377722] [] disk_unblock_events+0x51/0x60 [ 39.383783] [] __blkdev_get+0x6b6/0xd60 [ 39.389415] [] ? __blkdev_put+0x840/0x840 [ 39.395209] [] ? fsnotify+0x114/0x1100 [ 39.401030] [] blkdev_get+0x2da/0x920 [ 39.406778] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 39.413526] [] ? bd_may_claim+0xd0/0xd0 [ 39.419175] [] ? bd_acquire+0x27/0x250 [ 39.424878] [] ? bd_acquire+0x88/0x250 [ 39.430416] [] ? _raw_spin_unlock+0x2c/0x50 [ 39.436381] [] blkdev_open+0x1a5/0x250 [ 39.441917] [] do_dentry_open+0x3ef/0xc90 [ 39.447713] [] ? blkdev_get_by_dev+0x70/0x70 [ 39.453771] [] vfs_open+0x11c/0x210 [ 39.459300] [] ? may_open.isra.20+0x14f/0x2a0 [ 39.465450] [] path_openat+0x542/0x2790 [ 39.471235] [] ? path_mountpoint+0x6c0/0x6c0 [ 39.477593] [] ? trace_hardirqs_on+0x10/0x10 [ 39.483795] [] ? expand_files.part.3+0x3a9/0x6d0 [ 39.490414] [] do_filp_open+0x197/0x270 [ 39.496040] [] ? may_open_dev+0xe0/0xe0 [ 39.501829] [] ? _raw_spin_unlock+0x2c/0x50 [ 39.507798] [] ? __alloc_fd+0x1d7/0x4a0 [ 39.513420] [] do_sys_open+0x30d/0x5c0 [ 39.518952] [] ? filp_open+0x70/0x70 [ 39.524441] [] ? up_read+0x1a/0x40 [ 39.529635] [] SyS_open+0x2d/0x40 [ 39.534838] [] ? do_sys_open+0x5c0/0x5c0 [ 39.540706] [] do_syscall_64+0x19f/0x550 [ 39.546413] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 39.553331] [ 39.554953] Allocated by task 2408: [ 39.558776] save_stack_trace+0x16/0x20 [ 39.562871] kasan_kmalloc.part.1+0x62/0xf0 [ 39.567346] kasan_kmalloc+0xaf/0xc0 [ 39.571060] kmem_cache_alloc_trace+0x117/0x2e0 [ 39.575880] alloc_disk_node+0x54/0x3a0 [ 39.579865] alloc_disk+0x18/0x20 [ 39.583511] loop_add+0x368/0x7a0 [ 39.586991] loop_control_ioctl+0x136/0x300 [ 39.591701] do_vfs_ioctl+0x1ac/0x11a0 [ 39.595928] SyS_ioctl+0x8f/0xc0 [ 39.599311] do_syscall_64+0x19f/0x550 [ 39.603201] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 39.608293] [ 39.609918] Freed by task 2418: [ 39.613203] save_stack_trace+0x16/0x20 [ 39.617357] kasan_slab_free+0xac/0x190 [ 39.621326] kfree+0xfb/0x310 [ 39.624443] disk_release+0x259/0x330 [ 39.628368] device_release+0x7e/0x220 [ 39.632253] kobject_put+0x148/0x250 [ 39.636112] put_disk+0x23/0x30 [ 39.639496] __blkdev_get+0x616/0xd60 [ 39.643296] blkdev_get+0x2da/0x920 [ 39.646994] blkdev_open+0x1a5/0x250 [ 39.650704] do_dentry_open+0x3ef/0xc90 [ 39.654676] vfs_open+0x11c/0x210 [ 39.658123] path_openat+0x542/0x2790 [ 39.662036] do_filp_open+0x197/0x270 [ 39.665832] do_sys_open+0x30d/0x5c0 [ 39.669722] SyS_open+0x2d/0x40 [ 39.672997] do_syscall_64+0x19f/0x550 [ 39.677158] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 39.682582] [ 39.684213] The buggy address belongs to the object at ffff8801c7fc0000 [ 39.684213] which belongs to the cache kmalloc-2048 of size 2048 [ 39.697256] The buggy address is located 1376 bytes inside of [ 39.697256] 2048-byte region [ffff8801c7fc0000, ffff8801c7fc0800) [ 39.709427] The buggy address belongs to the page: [ 39.714466] page:ffffea00071ff000 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 39.724711] flags: 0x4000000000004080(slab|head) [ 39.729458] page dumped because: kasan: bad access detected [ 39.735156] [ 39.736988] Memory state around the buggy address: [ 39.741915] ffff8801c7fc0400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 39.749268] ffff8801c7fc0480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 39.757106] >ffff8801c7fc0500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 39.764592] ^ [ 39.771090] ffff8801c7fc0580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 39.778793] ffff8801c7fc0600: 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 39.786700] ================================================================== [ 39.794483] Disabling lock debugging due to kernel taint [ 39.804236] Kernel panic - not syncing: panic_on_warn set ... [ 39.804236] [ 39.811890] CPU: 1 PID: 2418 Comm: blkid Tainted: G B 4.9.141+ #1 [ 39.819371] ffff8801c78cf658 ffffffff81b42e79 ffffffff82e37630 00000000ffffffff [ 39.827655] 0000000000000000 0000000000000001 0000000000000000 ffff8801c78cf718 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 39.836209] ffffffff813f7125 0000000041b58ab3 ffffffff82e2b62b ffffffff813f6f66 [ 39.844398] Call Trace: [ 39.846992] [] dump_stack+0xc1/0x128 [ 39.852353] [] panic+0x1bf/0x39f [ 39.857362] [] ? add_taint.cold.5+0x16/0x16 [ 39.863629] [] ? ___preempt_schedule+0x16/0x18 [ 39.870134] [] kasan_end_report+0x47/0x4f [ 39.876451] [] kasan_report.cold.6+0x76/0x2fe [ 39.882911] [] ? disk_unblock_events+0x51/0x60 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 39.889145] [] __asan_report_load8_noabort+0x14/0x20 [ 39.895901] [] disk_unblock_events+0x51/0x60 [ 39.901960] [] __blkdev_get+0x6b6/0xd60 [ 39.907592] [] ? __blkdev_put+0x840/0x840 [ 39.914047] [] ? fsnotify+0x114/0x1100 [ 39.919583] [] blkdev_get+0x2da/0x920 [ 39.925163] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 39.932169] [] ? bd_may_claim+0xd0/0xd0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 39.937789] [] ? bd_acquire+0x27/0x250 [ 39.943324] [] ? bd_acquire+0x88/0x250 [ 39.948865] [] ? _raw_spin_unlock+0x2c/0x50 [ 39.954831] [] blkdev_open+0x1a5/0x250 [ 39.960485] [] do_dentry_open+0x3ef/0xc90 [ 39.966282] [] ? blkdev_get_by_dev+0x70/0x70 [ 39.972627] [] vfs_open+0x11c/0x210 [ 39.978075] [] ? may_open.isra.20+0x14f/0x2a0 [ 39.984218] [] 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 39.990006] [] ? path_mountpoint+0x6c0/0x6c0 [ 39.996381] [] ? trace_hardirqs_on+0x10/0x10 [ 40.002601] [] ? expand_files.part.3+0x3a9/0x6d0 [ 40.009012] [] do_filp_open+0x197/0x270 [ 40.014762] [] ? may_open_dev+0xe0/0xe0 [ 40.020739] [] ? _raw_spin_unlock+0x2c/0x50 [ 40.027273] [] ? __alloc_fd+0x1d7/0x4a0 [ 40.033312] [] 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 40.038848] [] ? filp_open+0x70/0x70 [ 40.044453] [] ? up_read+0x1a/0x40 [ 40.049644] [] SyS_open+0x2d/0x40 [ 40.054771] [] ? do_sys_open+0x5c0/0x5c0 [ 40.060483] [] do_syscall_64+0x19f/0x550 [ 40.066217] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 40.073502] Kernel Offset: disabled [ 40.077128] Rebooting in 86400 seconds..