[....] 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[ 10.717736] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.090308] random: sshd: uninitialized urandom read (32 bytes read) [ 21.178234] random: crng init done Warning: Permanently added '10.128.10.55' (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 [ 38.201693] ================================================================== [ 38.209108] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 38.215854] Read of size 8 at addr ffff8801d9b08de0 by task syz-executor280/2603 [ 38.223379] [ 38.225008] CPU: 1 PID: 2603 Comm: syz-executor280 Not tainted 4.9.141+ #23 [ 38.232100] ffff8801c64af6e8 ffffffff81b42e79 ffffea000766c200 ffff8801d9b08de0 [ 38.240191] 0000000000000000 ffff8801d9b08de0 0000000000000000 ffff8801c64af720 executing program executing program executing program executing program executing program executing program [ 38.248295] ffffffff815009b8 ffff8801d9b08de0 0000000000000008 0000000000000000 [ 38.256370] Call Trace: [ 38.258956] [] dump_stack+0xc1/0x128 [ 38.264319] [] print_address_description+0x6c/0x234 [ 38.270989] [] kasan_report.cold.6+0x242/0x2fe [ 38.277221] [] ? disk_unblock_events+0x51/0x60 [ 38.283452] [] __asan_report_load8_noabort+0x14/0x20 [ 38.290205] [] disk_unblock_events+0x51/0x60 [ 38.296263] [] __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 [ 38.301909] [] ? __blkdev_put+0x840/0x840 [ 38.307703] [] ? fsnotify+0x114/0x1100 [ 38.313246] [] blkdev_get+0x2da/0x920 [ 38.318702] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 38.325459] [] ? bd_may_claim+0xd0/0xd0 [ 38.331083] [] ? bd_acquire+0x27/0x250 [ 38.336622] [] ? bd_acquire+0x88/0x250 [ 38.342164] [] ? _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 [ 38.348142] [] blkdev_open+0x1a5/0x250 [ 38.353687] [] do_dentry_open+0x3ef/0xc90 [ 38.359513] [] ? blkdev_get_by_dev+0x70/0x70 [ 38.365576] [] vfs_open+0x11c/0x210 [ 38.370864] [] ? may_open.isra.20+0x14f/0x2a0 [ 38.377015] [] path_openat+0x542/0x2790 [ 38.382636] [] ? path_mountpoint+0x6c0/0x6c0 [ 38.388695] [] ? trace_hardirqs_on+0x10/0x10 [ 38.394761] [] ? 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 executing program executing program executing program [ 38.401169] [] do_filp_open+0x197/0x270 [ 38.406788] [] ? may_open_dev+0xe0/0xe0 [ 38.412410] [] ? _raw_spin_unlock+0x2c/0x50 [ 38.418378] [] ? __alloc_fd+0x1d7/0x4a0 [ 38.423999] [] do_sys_open+0x30d/0x5c0 [ 38.429538] [] ? filp_open+0x70/0x70 [ 38.434900] [] ? up_read+0x1a/0x40 [ 38.440096] [] ? loop_probe+0x180/0x180 [ 38.445720] [] compat_SyS_open+0x2a/0x40 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 38.451443] [] ? compat_SyS_getdents64+0x280/0x280 [ 38.458020] [] do_fast_syscall_32+0x2f1/0xa10 [ 38.464166] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 38.470830] [] entry_SYSENTER_compat+0x90/0xa2 [ 38.477053] [ 38.478675] Allocated by task 2603: [ 38.482308] save_stack_trace+0x16/0x20 [ 38.486290] kasan_kmalloc.part.1+0x62/0xf0 [ 38.490608] kasan_kmalloc+0xaf/0xc0 [ 38.494318] kmem_cache_alloc_trace+0x117/0x2e0 [ 38.498990] alloc_disk_node+0x54/0x3a0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 38.502958] alloc_disk+0x18/0x20 [ 38.506406] loop_add+0x368/0x7a0 [ 38.509851] loop_probe+0x14f/0x180 [ 38.513484] kobj_lookup+0x223/0x410 [ 38.517192] get_gendisk+0x39/0x2d0 [ 38.520823] __blkdev_get+0x351/0xd60 [ 38.524620] blkdev_get+0x2da/0x920 [ 38.528241] blkdev_open+0x1a5/0x250 [ 38.531956] do_dentry_open+0x3ef/0xc90 [ 38.535931] vfs_open+0x11c/0x210 [ 38.539385] path_openat+0x542/0x2790 [ 38.543193] do_filp_open+0x197/0x270 [ 38.546998] do_sys_open+0x30d/0x5c0 [ 38.550711] compat_SyS_open+0x2a/0x40 [ 38.554606] do_fast_syscall_32+0x2f1/0xa10 [ 38.558920] entry_SYSENTER_compat+0x90/0xa2 [ 38.563317] [ 38.564936] Freed by task 2603: [ 38.568210] save_stack_trace+0x16/0x20 [ 38.572177] kasan_slab_free+0xac/0x190 [ 38.576150] kfree+0xfb/0x310 [ 38.579249] disk_release+0x259/0x330 [ 38.583058] device_release+0x7e/0x220 [ 38.586966] kobject_put+0x148/0x250 [ 38.590676] put_disk+0x23/0x30 [ 38.593950] __blkdev_get+0x616/0xd60 [ 38.597755] blkdev_get+0x2da/0x920 [ 38.601378] blkdev_open+0x1a5/0x250 [ 38.605088] do_dentry_open+0x3ef/0xc90 [ 38.609057] vfs_open+0x11c/0x210 [ 38.612533] path_openat+0x542/0x2790 [ 38.616325] do_filp_open+0x197/0x270 [ 38.620124] do_sys_open+0x30d/0x5c0 [ 38.623834] compat_SyS_open+0x2a/0x40 [ 38.627717] do_fast_syscall_32+0x2f1/0xa10 [ 38.632039] entry_SYSENTER_compat+0x90/0xa2 [ 38.636433] [ 38.638055] The buggy address belongs to the object at ffff8801d9b08880 [ 38.638055] which belongs to the cache kmalloc-2048 of size 2048 [ 38.650881] The buggy address is located 1376 bytes inside of [ 38.650881] 2048-byte region [ffff8801d9b08880, ffff8801d9b09080) [ 38.662923] The buggy address belongs to the page: [ 38.667851] page:ffffea000766c200 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 38.678096] flags: 0x4000000000004080(slab|head) [ 38.682840] page dumped because: kasan: bad access detected [ 38.688540] [ 38.690160] Memory state around the buggy address: [ 38.695087] ffff8801d9b08c80: 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 [ 38.702445] ffff8801d9b08d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.709803] >ffff8801d9b08d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.717157] ^ [ 38.723642] ffff8801d9b08e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.731002] ffff8801d9b08e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.738354] ================================================================== [ 38.745704] 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 [ 38.756524] Kernel panic - not syncing: panic_on_warn set ... [ 38.756524] [ 38.763901] CPU: 1 PID: 2603 Comm: syz-executor280 Tainted: G B 4.9.141+ #23 [ 38.772434] ffff8801c64af648 ffffffff81b42e79 ffffffff82e37630 00000000ffffffff [ 38.780549] 0000000000000000 0000000000000001 0000000000000000 ffff8801c64af708 [ 38.788693] ffffffff813f7125 0000000041b58ab3 ffffffff82e2b62b ffffffff813f6f66 [ 38.796775] Call Trace: [ 38.799364] [] 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 [ 38.804730] [] panic+0x1bf/0x39f [ 38.809750] [] ? add_taint.cold.5+0x16/0x16 [ 38.815729] [] ? ___preempt_schedule+0x16/0x18 [ 38.821964] [] kasan_end_report+0x47/0x4f [ 38.827762] [] kasan_report.cold.6+0x76/0x2fe [ 38.833909] [] ? disk_unblock_events+0x51/0x60 [ 38.840139] [] __asan_report_load8_noabort+0x14/0x20 [ 38.846898] [] 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 [ 38.852956] [] __blkdev_get+0x6b6/0xd60 [ 38.858576] [] ? __blkdev_put+0x840/0x840 [ 38.864372] [] ? fsnotify+0x114/0x1100 [ 38.869906] [] blkdev_get+0x2da/0x920 [ 38.875354] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 38.882108] [] ? bd_may_claim+0xd0/0xd0 [ 38.887736] [] ? bd_acquire+0x27/0x250 [ 38.893271] [] ? bd_acquire+0x88/0x250 [ 38.898821] [] ? _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 [ 38.904789] [] blkdev_open+0x1a5/0x250 [ 38.910328] [] do_dentry_open+0x3ef/0xc90 [ 38.916120] [] ? blkdev_get_by_dev+0x70/0x70 [ 38.922174] [] vfs_open+0x11c/0x210 [ 38.927448] [] ? may_open.isra.20+0x14f/0x2a0 [ 38.933591] [] path_openat+0x542/0x2790 [ 38.939209] [] ? path_mountpoint+0x6c0/0x6c0 [ 38.945302] [] ? trace_hardirqs_on+0x10/0x10 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 38.951357] [] ? expand_files.part.3+0x3a9/0x6d0 [ 38.957764] [] do_filp_open+0x197/0x270 [ 38.963382] [] ? may_open_dev+0xe0/0xe0 [ 38.969001] [] ? _raw_spin_unlock+0x2c/0x50 [ 38.974971] [] ? __alloc_fd+0x1d7/0x4a0 [ 38.980596] [] do_sys_open+0x30d/0x5c0 [ 38.986131] [] ? filp_open+0x70/0x70 [ 38.991492] [] ? up_read+0x1a/0x40 [ 38.996692] [] ? loop_probe+0x180/0x180 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 39.002322] [] compat_SyS_open+0x2a/0x40 [ 39.008030] [] ? compat_SyS_getdents64+0x280/0x280 [ 39.014610] [] do_fast_syscall_32+0x2f1/0xa10 [ 39.020761] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 39.027427] [] entry_SYSENTER_compat+0x90/0xa2 [ 39.033973] Kernel Offset: disabled [ 39.037592] Rebooting in 86400 seconds..