[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 12.447322] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 15.065175] random: sshd: uninitialized urandom read (32 bytes read) [ 15.362350] random: sshd: uninitialized urandom read (32 bytes read) [ 16.071867] random: sshd: uninitialized urandom read (32 bytes read) [ 16.210926] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.15' (ECDSA) to the list of known hosts. [ 21.666224] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 23.013633] ================================================================== [ 23.021085] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 23.027848] Read of size 8 at addr ffff8801d8a3e2e0 by task blkid/4284 [ 23.034520] [ 23.036148] CPU: 1 PID: 4284 Comm: blkid Not tainted 4.9.96-g71fce1e #13 [ 23.042986] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 23.052367] ffff8801d81df6d8 ffffffff81eb0b69 ffffea0007628e00 ffff8801d8a3e2e0 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 23.060498] 0000000000000000 ffff8801d8a3e2e0 0000000000000000 ffff8801d81df710 [ 23.068605] ffffffff8156540b ffff8801d8a3e2e0 0000000000000008 0000000000000000 [ 23.076694] Call Trace: [ 23.079276] [] dump_stack+0xc1/0x128 [ 23.084644] [] print_address_description+0x6c/0x234 [ 23.091314] [] kasan_report.cold.6+0x242/0x2fe [ 23.097554] [] ? disk_unblock_events+0x51/0x60 [ 23.103793] [] __asan_report_load8_noabort+0x14/0x20 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 23.110553] [] disk_unblock_events+0x51/0x60 [ 23.116616] [] __blkdev_get+0x6b6/0xd60 [ 23.122250] [] ? __blkdev_put+0x840/0x840 [ 23.128064] [] ? fsnotify+0x114/0x1100 [ 23.133621] [] blkdev_get+0x2da/0x920 [ 23.139085] [] ? bd_may_claim+0xd0/0xd0 [ 23.144723] [] ? bd_acquire+0x27/0x250 [ 23.150272] [] ? bd_acquire+0x88/0x250 [ 23.155835] [] ? _raw_spin_unlock+0x2c/0x50 executing program executing program executing program executing program executing program executing program executing program executing program [ 23.161819] [] blkdev_open+0x1a5/0x250 [ 23.167381] [] do_dentry_open+0x703/0xc80 [ 23.173190] [] ? blkdev_get_by_dev+0x70/0x70 [ 23.179256] [] vfs_open+0x11c/0x210 [ 23.184570] [] ? may_open.isra.57+0x14f/0x2a0 [ 23.190721] [] path_openat+0x758/0x3590 [ 23.196353] [] ? save_stack+0xa9/0xd0 [ 23.201813] [] ? path_lookupat.isra.41+0x410/0x410 [ 23.208407] [] ? __lock_is_held+0xa2/0xf0 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 23.214219] [] do_filp_open+0x197/0x270 [ 23.219851] [] ? may_open_dev+0xe0/0xe0 [ 23.225487] [] ? _raw_spin_unlock+0x2c/0x50 [ 23.231467] [] ? __alloc_fd+0x1d7/0x4a0 [ 23.237103] [] do_sys_open+0x30d/0x5c0 [ 23.242649] [] ? filp_open+0x70/0x70 [ 23.248027] [] ? up_read+0x1a/0x40 [ 23.253235] [] ? __do_page_fault+0x183/0xd50 [ 23.259321] [] SyS_open+0x2d/0x40 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 23.264449] [] ? do_sys_open+0x5c0/0x5c0 [ 23.270166] [] do_syscall_64+0x1a6/0x490 [ 23.275907] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 23.283656] [ 23.285278] Allocated by task 4273: [ 23.288911] save_stack_trace+0x16/0x20 [ 23.292884] save_stack+0x43/0xd0 [ 23.296360] kasan_kmalloc+0xc7/0xe0 [ 23.300074] kmem_cache_alloc_trace+0xfd/0x2b0 [ 23.304663] alloc_disk_node+0x54/0x3a0 [ 23.308637] alloc_disk+0x18/0x20 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 23.312111] loop_add+0x33b/0x770 [ 23.315566] loop_probe+0x14f/0x180 [ 23.319195] kobj_lookup+0x223/0x410 [ 23.322917] get_gendisk+0x39/0x2d0 [ 23.326557] __blkdev_get+0x351/0xd60 [ 23.330368] blkdev_get+0x488/0x920 [ 23.334009] blkdev_open+0x1a5/0x250 [ 23.337730] do_dentry_open+0x703/0xc80 [ 23.341714] vfs_open+0x11c/0x210 [ 23.345184] path_openat+0x758/0x3590 [ 23.348992] do_filp_open+0x197/0x270 [ 23.352797] do_sys_open+0x30d/0x5c0 [ 23.356508] SyS_open+0x2d/0x40 [ 23.359788] do_syscall_64+0x1a6/0x490 executing program executing program executing program executing program executing program executing program executing program executing program [ 23.363676] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 23.368775] [ 23.370445] Freed by task 4284: [ 23.373732] save_stack_trace+0x16/0x20 [ 23.377706] save_stack+0x43/0xd0 [ 23.381161] kasan_slab_free+0x72/0xc0 [ 23.385073] kfree+0xfb/0x310 [ 23.388182] disk_release+0x259/0x330 [ 23.391984] device_release+0x7e/0x220 [ 23.395883] kobject_release+0x103/0x1b0 [ 23.399951] kobject_put+0x6d/0xd0 [ 23.403487] put_disk+0x23/0x30 [ 23.406768] __blkdev_get+0x616/0xd60 [ 23.410566] blkdev_get+0x2da/0x920 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 23.414196] blkdev_open+0x1a5/0x250 [ 23.417908] do_dentry_open+0x703/0xc80 [ 23.421879] vfs_open+0x11c/0x210 [ 23.425332] path_openat+0x758/0x3590 [ 23.429129] do_filp_open+0x197/0x270 [ 23.432926] do_sys_open+0x30d/0x5c0 [ 23.436641] SyS_open+0x2d/0x40 [ 23.439916] do_syscall_64+0x1a6/0x490 [ 23.443799] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 23.448887] [ 23.450514] The buggy address belongs to the object at ffff8801d8a3dd80 [ 23.450514] which belongs to the cache kmalloc-2048 of size 2048 executing program executing program executing program executing program executing program executing program executing program executing program [ 23.463347] The buggy address is located 1376 bytes inside of [ 23.463347] 2048-byte region [ffff8801d8a3dd80, ffff8801d8a3e580) [ 23.475395] The buggy address belongs to the page: [ 23.480332] page:ffffea0007628e00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 23.490562] flags: 0x8000000000004080(slab|head) [ 23.495308] page dumped because: kasan: bad access detected [ 23.501021] [ 23.502645] Memory state around the buggy address: [ 23.507570] ffff8801d8a3e180: 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 [ 23.514925] ffff8801d8a3e200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 23.522284] >ffff8801d8a3e280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 23.529642] ^ [ 23.536239] ffff8801d8a3e300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 23.543602] ffff8801d8a3e380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 23.550971] ================================================================== [ 23.558343] 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 [ 23.597728] Kernel panic - not syncing: panic_on_warn set ... [ 23.597728] [ 23.605145] CPU: 1 PID: 4284 Comm: blkid Tainted: G B 4.9.96-g71fce1e #13 [ 23.613194] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 23.622547] ffff8801d81df638 ffffffff81eb0b69 ffffffff841c492d 00000000ffffffff [ 23.630608] 0000000000000000 0000000000000001 0000000000000000 ffff8801d81df6f8 [ 23.638686] ffffffff8141f975 0000000041b58ab3 ffffffff841b8030 ffffffff8141f7b6 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 23.646818] Call Trace: [ 23.649400] [] dump_stack+0xc1/0x128 [ 23.654771] [] panic+0x1bf/0x3bc [ 23.659802] [] ? add_taint.cold.6+0x16/0x16 [ 23.665787] [] ? ___preempt_schedule+0x16/0x18 [ 23.672034] [] kasan_end_report+0x47/0x4f [ 23.677863] [] kasan_report.cold.6+0x76/0x2fe [ 23.684029] [] ? disk_unblock_events+0x51/0x60 [ 23.690271] [] __asan_report_load8_noabort+0x14/0x20 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 23.697041] [] disk_unblock_events+0x51/0x60 [ 23.703114] [] __blkdev_get+0x6b6/0xd60 [ 23.708743] [] ? __blkdev_put+0x840/0x840 [ 23.714550] [] ? fsnotify+0x114/0x1100 [ 23.720107] [] blkdev_get+0x2da/0x920 [ 23.725582] [] ? bd_may_claim+0xd0/0xd0 [ 23.731218] [] ? bd_acquire+0x27/0x250 [ 23.736764] [] ? bd_acquire+0x88/0x250 [ 23.742312] [] ? _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 [ 23.748291] [] blkdev_open+0x1a5/0x250 [ 23.753847] [] do_dentry_open+0x703/0xc80 [ 23.759649] [] ? blkdev_get_by_dev+0x70/0x70 [ 23.765714] [] vfs_open+0x11c/0x210 [ 23.771001] [] ? may_open.isra.57+0x14f/0x2a0 [ 23.777153] [] path_openat+0x758/0x3590 [ 23.782789] [] ? save_stack+0xa9/0xd0 [ 23.788290] [] ? path_lookupat.isra.41+0x410/0x410 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 [ 23.794885] [] ? __lock_is_held+0xa2/0xf0 [ 23.800703] [] do_filp_open+0x197/0x270 [ 23.806351] [] ? may_open_dev+0xe0/0xe0 [ 23.811996] [] ? _raw_spin_unlock+0x2c/0x50 [ 23.817989] [] ? __alloc_fd+0x1d7/0x4a0 [ 23.823632] [] do_sys_open+0x30d/0x5c0 [ 23.829191] [] ? filp_open+0x70/0x70 [ 23.834563] [] ? up_read+0x1a/0x40 [ 23.839765] [] ? __do_page_fault+0x183/0xd50 executing program executing program executing program executing program executing program executing program [ 23.845828] [] SyS_open+0x2d/0x40 [ 23.850931] [] ? do_sys_open+0x5c0/0x5c0 [ 23.856644] [] do_syscall_64+0x1a6/0x490 [ 23.862372] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 23.869798] Dumping ftrace buffer: [ 23.873341] (ftrace buffer empty) [ 23.877038] Kernel Offset: disabled [ 23.880649] Rebooting in 86400 seconds..