[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] 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[ 10.327227] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 16.393826] random: crng init done Warning: Permanently added '10.128.0.39' (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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.259032] ================================================================== [ 34.266536] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 34.273297] Read of size 8 at addr ffff8801c68ec0e0 by task blkid/3957 [ 34.279951] [ 34.281611] CPU: 1 PID: 3957 Comm: blkid Not tainted 4.9.126+ #90 [ 34.287955] ffff8801c6b076f8 ffffffff81af1049 ffffea00071a3a00 ffff8801c68ec0e0 [ 34.296064] 0000000000000000 ffff8801c68ec0e0 0000000000000000 ffff8801c6b07730 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.304154] ffffffff814e136d ffff8801c68ec0e0 0000000000000008 0000000000000000 [ 34.312183] Call Trace: [ 34.314829] [] dump_stack+0xc1/0x128 [ 34.320210] [] print_address_description+0x6c/0x234 [ 34.327052] [] kasan_report.cold.6+0x242/0x2fe [ 34.333269] [] ? disk_unblock_events+0x51/0x60 [ 34.339588] [] __asan_report_load8_noabort+0x14/0x20 [ 34.346381] [] disk_unblock_events+0x51/0x60 [ 34.352553] [] __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 [ 34.358293] [] ? __blkdev_put+0x840/0x840 [ 34.364084] [] ? fsnotify+0x114/0x1100 [ 34.369713] [] blkdev_get+0x2da/0x920 [ 34.375175] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 34.381919] [] ? bd_may_claim+0xd0/0xd0 [ 34.387526] [] ? bd_acquire+0x27/0x250 [ 34.393057] [] ? bd_acquire+0x88/0x250 [ 34.398587] [] ? _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 [ 34.404545] [] blkdev_open+0x1a5/0x250 [ 34.410069] [] do_dentry_open+0x3ef/0xc90 [ 34.415859] [] ? blkdev_get_by_dev+0x70/0x70 [ 34.421909] [] vfs_open+0x11c/0x210 [ 34.427174] [] ? may_open.isra.20+0x14f/0x2a0 [ 34.433314] [] path_openat+0x542/0x2790 [ 34.438923] [] ? path_mountpoint+0x6c0/0x6c0 [ 34.444966] [] ? trace_hardirqs_on+0x10/0x10 [ 34.451016] [] ? 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 [ 34.457404] [] do_filp_open+0x197/0x270 [ 34.463025] [] ? may_open_dev+0xe0/0xe0 [ 34.468641] [] ? _raw_spin_unlock+0x2c/0x50 [ 34.474600] [] ? __alloc_fd+0x1d7/0x4a0 [ 34.480232] [] do_sys_open+0x30d/0x5c0 [ 34.485788] [] ? filp_open+0x70/0x70 [ 34.491200] [] ? up_read+0x1a/0x40 [ 34.496377] [] SyS_open+0x2d/0x40 [ 34.501460] [] ? 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 [ 34.507159] [] do_syscall_64+0x19f/0x480 [ 34.512879] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 34.519805] [ 34.521422] Allocated by task 3933: [ 34.525034] save_stack_trace+0x16/0x20 [ 34.529022] kasan_kmalloc.part.1+0x62/0xf0 [ 34.533327] kasan_kmalloc+0xaf/0xc0 [ 34.537031] kmem_cache_alloc_trace+0x117/0x2e0 [ 34.541699] alloc_disk_node+0x54/0x3a0 [ 34.545702] alloc_disk+0x18/0x20 [ 34.549178] loop_add+0x33b/0x770 [ 34.552620] loop_probe+0x14f/0x180 [ 34.556351] 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 [ 34.560060] get_gendisk+0x39/0x2d0 [ 34.563788] __blkdev_get+0x351/0xd60 [ 34.567581] blkdev_get+0x2da/0x920 [ 34.571191] blkdev_open+0x1a5/0x250 [ 34.574892] do_dentry_open+0x3ef/0xc90 [ 34.578851] vfs_open+0x11c/0x210 [ 34.582293] path_openat+0x542/0x2790 [ 34.586082] do_filp_open+0x197/0x270 [ 34.589886] do_sys_open+0x30d/0x5c0 [ 34.593582] SyS_open+0x2d/0x40 [ 34.596852] do_syscall_64+0x19f/0x480 [ 34.600733] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 34.605836] [ 34.607448] Freed by task 3957: executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.610710] save_stack_trace+0x16/0x20 [ 34.614671] kasan_slab_free+0xac/0x190 [ 34.618629] kfree+0xfb/0x310 [ 34.621742] disk_release+0x259/0x330 [ 34.625535] device_release+0x7e/0x220 [ 34.629416] kobject_put+0x148/0x250 [ 34.633127] put_disk+0x23/0x30 [ 34.636399] __blkdev_get+0x616/0xd60 [ 34.640215] blkdev_get+0x2da/0x920 [ 34.643829] blkdev_open+0x1a5/0x250 [ 34.647531] do_dentry_open+0x3ef/0xc90 [ 34.651501] vfs_open+0x11c/0x210 [ 34.654942] 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 [ 34.658738] do_filp_open+0x197/0x270 [ 34.662526] do_sys_open+0x30d/0x5c0 [ 34.666224] SyS_open+0x2d/0x40 [ 34.669517] do_syscall_64+0x19f/0x480 [ 34.673399] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 34.678492] [ 34.680119] The buggy address belongs to the object at ffff8801c68ebb80 [ 34.680119] which belongs to the cache kmalloc-2048 of size 2048 [ 34.692958] The buggy address is located 1376 bytes inside of [ 34.692958] 2048-byte region [ffff8801c68ebb80, ffff8801c68ec380) [ 34.704998] 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 [ 34.709998] page:ffffea00071a3a00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 34.720246] flags: 0x4000000000004080(slab|head) [ 34.725003] page dumped because: kasan: bad access detected [ 34.730699] [ 34.732321] Memory state around the buggy address: [ 34.737276] ffff8801c68ebf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.744646] ffff8801c68ec000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.751999] >ffff8801c68ec080: 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 [ 34.759349] ^ [ 34.765834] ffff8801c68ec100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.773206] ffff8801c68ec180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.780555] ================================================================== [ 34.787899] Disabling lock debugging due to kernel taint [ 34.797167] Kernel panic - not syncing: panic_on_warn set ... [ 34.797167] executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.804556] CPU: 1 PID: 3957 Comm: blkid Tainted: G B 4.9.126+ #90 [ 34.811996] ffff8801c6b07658 ffffffff81af1049 ffffffff82c346e0 00000000ffffffff [ 34.820074] 0000000000000000 0000000000000001 0000000000000000 ffff8801c6b07718 [ 34.828171] ffffffff813df5e5 0000000041b58ab3 ffffffff82c286e3 ffffffff813df426 [ 34.836246] Call Trace: [ 34.838830] [] dump_stack+0xc1/0x128 [ 34.844190] [] panic+0x1bf/0x39f [ 34.849216] [] ? add_taint.cold.6+0x16/0x16 [ 34.855242] [] ? ___preempt_schedule+0x16/0x18 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.861489] [] kasan_end_report+0x47/0x4f [ 34.867426] [] kasan_report.cold.6+0x76/0x2fe [ 34.873559] [] ? disk_unblock_events+0x51/0x60 [ 34.879815] [] __asan_report_load8_noabort+0x14/0x20 [ 34.886554] [] disk_unblock_events+0x51/0x60 [ 34.892665] [] __blkdev_get+0x6b6/0xd60 [ 34.898283] [] ? __blkdev_put+0x840/0x840 [ 34.904075] [] ? fsnotify+0x114/0x1100 [ 34.909613] [] blkdev_get+0x2da/0x920 [ 34.915057] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 34.921808] [] ? bd_may_claim+0xd0/0xd0 [ 34.927422] [] ? bd_acquire+0x27/0x250 [ 34.932943] [] ? bd_acquire+0x88/0x250 [ 34.938480] [] ? _raw_spin_unlock+0x2c/0x50 [ 34.944450] [] blkdev_open+0x1a5/0x250 [ 34.949981] [] do_dentry_open+0x3ef/0xc90 [ 34.955790] [] ? blkdev_get_by_dev+0x70/0x70 [ 34.961831] [] vfs_open+0x11c/0x210 [ 34.967116] [] ? may_open.isra.20+0x14f/0x2a0 [ 34.973294] [] path_openat+0x542/0x2790 [ 34.978897] [] ? path_mountpoint+0x6c0/0x6c0 [ 34.984926] [] ? trace_hardirqs_on+0x10/0x10 [ 34.990956] [] ? expand_files.part.3+0x3a9/0x6d0 [ 34.997350] [] do_filp_open+0x197/0x270 [ 35.002963] [] ? may_open_dev+0xe0/0xe0 [ 35.008562] [] ? _raw_spin_unlock+0x2c/0x50 [ 35.014525] [] ? __alloc_fd+0x1d7/0x4a0 [ 35.020129] [] do_sys_open+0x30d/0x5c0 [ 35.025640] [] ? filp_open+0x70/0x70 [ 35.030988] [] ? up_read+0x1a/0x40 [ 35.036151] [] SyS_open+0x2d/0x40 [ 35.041227] [] ? do_sys_open+0x5c0/0x5c0 [ 35.046907] [] do_syscall_64+0x19f/0x480 [ 35.052591] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 35.059737] Dumping ftrace buffer: [ 35.063252] (ftrace buffer empty) [ 35.066941] Kernel Offset: disabled [ 35.070543] Rebooting in 86400 seconds..