[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [ 10.219761] random: sshd: uninitialized urandom read (32 bytes read) [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 11.223858] random: crng init done Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.38' (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 syzkaller login: [ 30.446843] ================================================================== [ 30.448169] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 30.449160] Read of size 8 at addr ffff8801cd4a7c60 by task blkid/2241 [ 30.450075] [ 30.450332] CPU: 0 PID: 2241 Comm: blkid Not tainted 4.9.141+ #1 [ 30.451369] ffff8801cd6576f8 ffffffff81b42e79 ffffea0007352800 ffff8801cd4a7c60 [ 30.452709] 0000000000000000 ffff8801cd4a7c60 0000000000000000 ffff8801cd657730 [ 30.453923] ffffffff815009b8 ffff8801cd4a7c60 0000000000000008 0000000000000000 [ 30.455132] Call Trace: [ 30.455515] [] dump_stack+0xc1/0x128 [ 30.456310] [] print_address_description+0x6c/0x234 [ 30.457447] [] kasan_report.cold.6+0x242/0x2fe [ 30.458561] [] ? disk_unblock_events+0x51/0x60 [ 30.459388] [] __asan_report_load8_noabort+0x14/0x20 [ 30.460359] [] disk_unblock_events+0x51/0x60 [ 30.461201] [] __blkdev_get+0x6b6/0xd60 [ 30.462207] [] ? __blkdev_put+0x840/0x840 [ 30.463048] [] ? fsnotify+0x114/0x1100 [ 30.463805] [] blkdev_get+0x2da/0x920 [ 30.464532] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 30.465491] [] ? bd_may_claim+0xd0/0xd0 [ 30.466237] [] ? bd_acquire+0x27/0x250 [ 30.468100] [] ? bd_acquire+0x88/0x250 [ 30.473606] [] ? _raw_spin_unlock+0x2c/0x50 [ 30.479545] [] blkdev_open+0x1a5/0x250 [ 30.485050] [] do_dentry_open+0x3ef/0xc90 [ 30.490816] [] ? blkdev_get_by_dev+0x70/0x70 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 30.496857] [] vfs_open+0x11c/0x210 [ 30.502104] [] ? may_open.isra.20+0x14f/0x2a0 [ 30.508224] [] path_openat+0x542/0x2790 [ 30.513822] [] ? path_mountpoint+0x6c0/0x6c0 [ 30.519851] [] ? trace_hardirqs_on+0x10/0x10 [ 30.525881] [] ? expand_files.part.3+0x3a9/0x6d0 [ 30.532272] [] do_filp_open+0x197/0x270 [ 30.537867] [] ? may_open_dev+0xe0/0xe0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 30.543462] [] ? _raw_spin_unlock+0x2c/0x50 [ 30.549405] [] ? __alloc_fd+0x1d7/0x4a0 [ 30.554999] [] do_sys_open+0x30d/0x5c0 [ 30.560508] [] ? filp_open+0x70/0x70 [ 30.565844] [] ? up_read+0x1a/0x40 [ 30.571007] [] SyS_open+0x2d/0x40 [ 30.576083] [] ? do_sys_open+0x5c0/0x5c0 [ 30.581769] [] do_syscall_64+0x19f/0x550 [ 30.587451] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 30.594348] executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 30.595959] Allocated by task 2232: [ 30.599567] save_stack_trace+0x16/0x20 [ 30.603520] kasan_kmalloc.part.1+0x62/0xf0 [ 30.607813] kasan_kmalloc+0xaf/0xc0 [ 30.611502] kmem_cache_alloc_trace+0x117/0x2e0 [ 30.616147] alloc_disk_node+0x54/0x3a0 [ 30.620108] alloc_disk+0x18/0x20 [ 30.623531] loop_add+0x368/0x7a0 [ 30.626953] loop_control_ioctl+0x136/0x300 [ 30.631247] do_vfs_ioctl+0x1ac/0x11a0 [ 30.635107] SyS_ioctl+0x8f/0xc0 [ 30.638445] do_syscall_64+0x19f/0x550 [ 30.642305] entry_SYSCALL_64_after_swapgs+0x5d/0xdb executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 30.647393] [ 30.648989] Freed by task 2241: [ 30.652254] save_stack_trace+0x16/0x20 [ 30.656201] kasan_slab_free+0xac/0x190 [ 30.660151] kfree+0xfb/0x310 [ 30.663228] disk_release+0x259/0x330 [ 30.667013] device_release+0x7e/0x220 [ 30.670869] kobject_put+0x148/0x250 [ 30.674568] put_disk+0x23/0x30 [ 30.677819] __blkdev_get+0x616/0xd60 [ 30.681589] blkdev_get+0x2da/0x920 [ 30.685185] blkdev_open+0x1a5/0x250 [ 30.688866] do_dentry_open+0x3ef/0xc90 [ 30.692825] vfs_open+0x11c/0x210 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 30.696251] path_openat+0x542/0x2790 [ 30.700021] do_filp_open+0x197/0x270 [ 30.703807] do_sys_open+0x30d/0x5c0 [ 30.707510] SyS_open+0x2d/0x40 [ 30.710763] do_syscall_64+0x19f/0x550 [ 30.714623] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 30.719691] [ 30.721289] The buggy address belongs to the object at ffff8801cd4a7700 [ 30.721289] which belongs to the cache kmalloc-2048 of size 2048 [ 30.734095] The buggy address is located 1376 bytes inside of [ 30.734095] 2048-byte region [ffff8801cd4a7700, ffff8801cd4a7f00) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 30.746109] The buggy address belongs to the page: [ 30.751010] page:ffffea0007352800 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 30.761182] flags: 0x4000000000004080(slab|head) [ 30.765907] page dumped because: kasan: bad access detected [ 30.771611] [ 30.773208] Memory state around the buggy address: [ 30.778226] ffff8801cd4a7b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.785559] ffff8801cd4a7b80: 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 [ 30.792888] >ffff8801cd4a7c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.800218] ^ [ 30.806679] ffff8801cd4a7c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.814009] ffff8801cd4a7d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.821335] ================================================================== [ 30.828660] Disabling lock debugging due to kernel taint [ 30.836779] Kernel panic - not syncing: panic_on_warn set ... [ 30.836779] executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 30.844128] CPU: 0 PID: 2241 Comm: blkid Tainted: G B 4.9.141+ #1 [ 30.851461] ffff8801cd657658 ffffffff81b42e79 ffffffff82e37630 00000000ffffffff [ 30.859535] 0000000000000000 0000000000000000 0000000000000000 ffff8801cd657718 [ 30.867517] ffffffff813f7125 0000000041b58ab3 ffffffff82e2b62b ffffffff813f6f66 [ 30.875520] Call Trace: [ 30.878107] [] dump_stack+0xc1/0x128 [ 30.883444] [] panic+0x1bf/0x39f [ 30.888434] [] ? add_taint.cold.5+0x16/0x16 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 30.894377] [] ? ___preempt_schedule+0x16/0x18 [ 30.900580] [] kasan_end_report+0x47/0x4f [ 30.906352] [] kasan_report.cold.6+0x76/0x2fe [ 30.912471] [] ? disk_unblock_events+0x51/0x60 [ 30.918680] [] __asan_report_load8_noabort+0x14/0x20 [ 30.925403] [] disk_unblock_events+0x51/0x60 [ 30.931432] [] __blkdev_get+0x6b6/0xd60 [ 30.937025] [] ? __blkdev_put+0x840/0x840 [ 30.942794] [] ? fsnotify+0x114/0x1100 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 30.948300] [] blkdev_get+0x2da/0x920 [ 30.953722] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 30.960444] [] ? bd_may_claim+0xd0/0xd0 [ 30.966036] [] ? bd_acquire+0x27/0x250 [ 30.971552] [] ? bd_acquire+0x88/0x250 [ 30.977071] [] ? _raw_spin_unlock+0x2c/0x50 [ 30.983019] [] blkdev_open+0x1a5/0x250 [ 30.988528] [] do_dentry_open+0x3ef/0xc90 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 30.994295] [] ? blkdev_get_by_dev+0x70/0x70 [ 31.000324] [] vfs_open+0x11c/0x210 [ 31.005575] [] ? may_open.isra.20+0x14f/0x2a0 [ 31.011691] [] path_openat+0x542/0x2790 [ 31.017301] [] ? path_mountpoint+0x6c0/0x6c0 [ 31.023332] [] ? trace_hardirqs_on+0x10/0x10 [ 31.029369] [] ? expand_files.part.3+0x3a9/0x6d0 [ 31.035752] [] do_filp_open+0x197/0x270 [ 31.041355] [] ? may_open_dev+0xe0/0xe0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 31.046956] [] ? _raw_spin_unlock+0x2c/0x50 [ 31.052947] [] ? __alloc_fd+0x1d7/0x4a0 [ 31.058559] [] do_sys_open+0x30d/0x5c0 [ 31.064069] [] ? filp_open+0x70/0x70 [ 31.069411] [] ? up_read+0x1a/0x40 [ 31.074571] [] SyS_open+0x2d/0x40 [ 31.079646] [] ? do_sys_open+0x5c0/0x5c0 [ 31.085456] [] do_syscall_64+0x19f/0x550 [ 31.091185] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 31.098469] Kernel Offset: disabled [ 31.102081] Rebooting in 86400 seconds..