[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 9.035022] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 29.119208] random: sshd: uninitialized urandom read (32 bytes read) [ 29.455292] random: sshd: uninitialized urandom read (32 bytes read) [ 29.576739] random: crng init done Warning: Permanently added '10.128.0.75' (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 [ 66.695300] ================================================================== [ 66.702728] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 66.709479] Read of size 8 at addr ffff8801d8654960 by task blkid/2633 [ 66.716130] [ 66.717756] CPU: 0 PID: 2633 Comm: blkid Not tainted 4.9.133+ #106 [ 66.724061] ffff8801d7a9f6f8 ffffffff81b37069 ffffea0007619400 ffff8801d8654960 [ 66.732300] 0000000000000000 ffff8801d8654960 0000000000000000 ffff8801d7a9f730 [ 66.740355] ffffffff81500a0d ffff8801d8654960 0000000000000008 0000000000000000 [ 66.748409] Call Trace: [ 66.751008] [] dump_stack+0xc1/0x128 [ 66.756371] [] print_address_description+0x6c/0x234 [ 66.763036] [] kasan_report.cold.6+0x242/0x2fe [ 66.769266] [] ? disk_unblock_events+0x51/0x60 [ 66.775498] [] __asan_report_load8_noabort+0x14/0x20 [ 66.782240] [] disk_unblock_events+0x51/0x60 [ 66.788288] [] __blkdev_get+0x6b6/0xd60 [ 66.793891] [] ? __blkdev_put+0x840/0x840 [ 66.799676] [] ? fsnotify+0x114/0x1100 [ 66.805314] [] blkdev_get+0x2da/0x920 [ 66.810755] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 66.817509] [] ? bd_may_claim+0xd0/0xd0 [ 66.823130] [] ? bd_acquire+0x27/0x250 [ 66.828673] [] ? bd_acquire+0x88/0x250 [ 66.834209] [] ? _raw_spin_unlock+0x2c/0x50 [ 66.840166] [] blkdev_open+0x1a5/0x250 [ 66.845682] [] do_dentry_open+0x3ef/0xc90 [ 66.851461] [] ? blkdev_get_by_dev+0x70/0x70 [ 66.857514] [] vfs_open+0x11c/0x210 [ 66.862796] [] ? may_open.isra.20+0x14f/0x2a0 [ 66.868936] [] path_openat+0x542/0x2790 [ 66.874559] [] ? path_mountpoint+0x6c0/0x6c0 [ 66.880654] [] ? trace_hardirqs_on+0x10/0x10 [ 66.886703] [] ? expand_files.part.3+0x3a9/0x6d0 [ 66.893104] [] do_filp_open+0x197/0x270 [ 66.898720] [] ? may_open_dev+0xe0/0xe0 [ 66.904344] [] ? _raw_spin_unlock+0x2c/0x50 [ 66.910304] [] ? __alloc_fd+0x1d7/0x4a0 [ 66.915912] [] do_sys_open+0x30d/0x5c0 [ 66.921458] [] ? filp_open+0x70/0x70 [ 66.926815] [] ? up_read+0x1a/0x40 [ 66.931998] [] SyS_open+0x2d/0x40 [ 66.937094] [] ? do_sys_open+0x5c0/0x5c0 [ 66.942800] [] do_syscall_64+0x19f/0x550 [ 66.948546] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 66.955464] [ 66.957076] Allocated by task 2625: [ 66.960684] save_stack_trace+0x16/0x20 [ 66.964642] kasan_kmalloc.part.1+0x62/0xf0 [ 66.968955] kasan_kmalloc+0xaf/0xc0 [ 66.972667] kmem_cache_alloc_trace+0x117/0x2e0 [ 66.977323] alloc_disk_node+0x54/0x3a0 [ 66.981279] alloc_disk+0x18/0x20 [ 66.984721] loop_add+0x368/0x7a0 [ 66.988150] loop_control_ioctl+0x136/0x300 [ 66.992458] do_vfs_ioctl+0x1ac/0x11a0 [ 66.996337] SyS_ioctl+0x8f/0xc0 [ 66.999697] do_syscall_64+0x19f/0x550 [ 67.003581] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 67.008671] [ 67.010288] Freed by task 2633: [ 67.013558] save_stack_trace+0x16/0x20 [ 67.017519] kasan_slab_free+0xac/0x190 [ 67.021473] kfree+0xfb/0x310 [ 67.024564] disk_release+0x259/0x330 [ 67.028358] device_release+0x7e/0x220 [ 67.032230] kobject_put+0x148/0x250 [ 67.035922] put_disk+0x23/0x30 [ 67.039183] __blkdev_get+0x616/0xd60 [ 67.042976] blkdev_get+0x2da/0x920 [ 67.046594] blkdev_open+0x1a5/0x250 [ 67.050300] do_dentry_open+0x3ef/0xc90 [ 67.054260] vfs_open+0x11c/0x210 [ 67.057694] path_openat+0x542/0x2790 [ 67.061481] do_filp_open+0x197/0x270 [ 67.065258] do_sys_open+0x30d/0x5c0 [ 67.068952] SyS_open+0x2d/0x40 [ 67.072229] do_syscall_64+0x19f/0x550 [ 67.076113] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 67.081203] [ 67.082830] The buggy address belongs to the object at ffff8801d8654400 [ 67.082830] which belongs to the cache kmalloc-2048 of size 2048 [ 67.095652] The buggy address is located 1376 bytes inside of [ 67.095652] 2048-byte region [ffff8801d8654400, ffff8801d8654c00) [ 67.107689] The buggy address belongs to the page: [ 67.112611] page:ffffea0007619400 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 67.122802] flags: 0x4000000000004080(slab|head) [ 67.127552] page dumped because: kasan: bad access detected [ 67.133245] [ 67.134854] Memory state around the buggy address: [ 67.139773] ffff8801d8654800: 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 [ 67.147125] ffff8801d8654880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.154476] >ffff8801d8654900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.161827] ^ [ 67.168310] ffff8801d8654980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.175656] ffff8801d8654a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.182989] ================================================================== [ 67.190322] 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 67.200443] Kernel panic - not syncing: panic_on_warn set ... [ 67.200443] [ 67.207816] CPU: 0 PID: 2633 Comm: blkid Tainted: G B 4.9.133+ #106 [ 67.215343] ffff8801d7a9f658 ffffffff81b37069 ffffffff82e359a0 00000000ffffffff [ 67.223404] 0000000000000000 0000000000000000 0000000000000000 ffff8801d7a9f718 [ 67.231475] ffffffff813f6a45 0000000041b58ab3 ffffffff82e299a3 ffffffff813f6886 [ 67.239549] Call Trace: [ 67.242141] [] dump_stack+0xc1/0x128 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 67.247503] [] panic+0x1bf/0x39f [ 67.252521] [] ? add_taint.cold.6+0x16/0x16 [ 67.258499] [] ? ___preempt_schedule+0x16/0x18 [ 67.264736] [] kasan_end_report+0x47/0x4f [ 67.270537] [] kasan_report.cold.6+0x76/0x2fe [ 67.276685] [] ? disk_unblock_events+0x51/0x60 [ 67.282912] [] __asan_report_load8_noabort+0x14/0x20 [ 67.289686] [] 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 [ 67.295749] [] __blkdev_get+0x6b6/0xd60 [ 67.301369] [] ? __blkdev_put+0x840/0x840 [ 67.307156] [] ? fsnotify+0x114/0x1100 [ 67.312686] [] blkdev_get+0x2da/0x920 [ 67.318134] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 67.324908] [] ? bd_may_claim+0xd0/0xd0 [ 67.330529] [] ? bd_acquire+0x27/0x250 [ 67.336066] [] ? bd_acquire+0x88/0x250 [ 67.341602] [] ? _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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 67.347568] [] blkdev_open+0x1a5/0x250 [ 67.353105] [] do_dentry_open+0x3ef/0xc90 [ 67.358896] [] ? blkdev_get_by_dev+0x70/0x70 [ 67.364948] [] vfs_open+0x11c/0x210 [ 67.370217] [] ? may_open.isra.20+0x14f/0x2a0 [ 67.376355] [] path_openat+0x542/0x2790 [ 67.381974] [] ? path_mountpoint+0x6c0/0x6c0 [ 67.388031] [] ? trace_hardirqs_on+0x10/0x10 [ 67.394085] [] ? 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 executing program executing program executing program executing program executing program executing program executing program executing program [ 67.400487] [] do_filp_open+0x197/0x270 [ 67.406107] [] ? may_open_dev+0xe0/0xe0 [ 67.411813] [] ? _raw_spin_unlock+0x2c/0x50 [ 67.417779] [] ? __alloc_fd+0x1d7/0x4a0 [ 67.423397] [] do_sys_open+0x30d/0x5c0 [ 67.428937] [] ? filp_open+0x70/0x70 [ 67.434295] [] ? up_read+0x1a/0x40 [ 67.439478] [] SyS_open+0x2d/0x40 [ 67.444582] [] ? do_sys_open+0x5c0/0x5c0 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 67.450288] [] do_syscall_64+0x19f/0x550 [ 67.455995] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 67.463220] Kernel Offset: disabled [ 67.466835] Rebooting in 86400 seconds..